Reverse velocity jet tamper disrupter enhancer with muzzle blast suppression

Abstract

Provided herein are fluid jet enhancement adapters for use with a propellant driven disrupter, and more particularly muzzle blast suppressor. The fluid jet enhancement muzzle blast suppressor may comprise a suppressor bore extending between the proximal end and the distal end with an inner suppressor surface that defines the suppressor bore. An outer suppressor surface opposably faces the inner suppressor surface, with a suppressor chamber positioned between the inner and outer suppressor surfaces. A plurality of passages connect the suppressor bore with the suppressor chamber, wherein the plurality of passages are sized to allow gas to move from the suppressor bore to the suppressor chamber and minimize liquid movement from the suppressor bore to the suppressor chamber.

Claims

1. A fluid jet enhancement muzzle suppressor for use with a propellant driven disrupter, the fluid jet enhancement muzzle suppressor comprising: a connection proximal end having a connection mechanism configured to operably connect to a propellant driven disrupter muzzle end; a suppressor distal end; a suppressor bore extending between the proximal end and the distal end; an inner suppressor surface that defines the suppressor bore; an outer suppressor surface opposably facing the inner suppressor surface; a suppressor chamber positioned between the inner and outer suppressor surfaces; a plurality of passages that connect the suppressor bore with the suppressor chamber, wherein the plurality of passages are sized to allow gas to move from the suppressor bore to the suppressor chamber and minimize liquid movement from the suppressor bore to the suppressor chamber; wherein the outer suppressor surface is a continuous surface that radially isolates the suppressor chamber from a surrounding environment; and wherein the suppressor bore has a diameter at the connection proximal end that is substantially equivalent to a propellant driven disrupter muzzle end inner diameter.

2. The fluid jet enhancement muzzle suppressor of claim 1, wherein the suppressor bore has a suppressor bore length and the propellant driven disrupter has a disrupter bore length, with a ratio of suppressor bore length to disrupter bore length that is greater than or equal to 0.25 and less than or equal to 1.5.

3. The fluid jet enhancement muzzle suppressor of claim 1, wherein the connection mechanism comprises a threaded end configured to rotationally connect to a corresponding threaded end of a disrupter barrel or a disrupter barrel adapter.

4. The fluid jet enhancement muzzle suppressor of claim 1, wherein the plurality of passages have an average diameter that is less than or equal to 3/16.

5. The fluid jet enhancement muzzle suppressor of claim 1, wherein the plurality of passages have a spatial density of between 2 passages cm.sup.2 to 8 passages cm.sup.2.

6. The fluid jet enhancement muzzle suppressor of claim 1, wherein the plurality of passages are confined to a distal portion of the suppressor bore, wherein the distal portion spans 50% or less of the suppressor bore longitudinal length.

7. The fluid jet enhancement muzzle suppressor of claim 1, wherein the plurality of passages are spatially aligned.

8. The fluid jet enhancement muzzle suppressor of claim 1, wherein the plurality of passages are sized so that less than 1% by mass of a disrupter fluid enters the suppressor chamber or a plurality of suppressor chambers.

9. The fluid jet enhancement muzzle suppressor of claim 1, wherein the plurality of passages are shaped to minimize fluid mass from entering the suppressor chamber or plurality of suppressor chambers, wherein the passages have a geometric shape that is one or more of circular, catenary, parabolic, oval, pill-shaped, star-shaped, square, rectangular and tear-drop shaped.

10. The fluid jet enhancement muzzle suppressor of claim 1, wherein the passages have an angle relative to the inner suppressor surface that is perpendicular, tapered, conical, or chamfered.

11. The fluid jet enhancement muzzle suppressor of claim 1, comprising a plurality of suppressor chambers.

12. The fluid jet enhancement muzzle suppressor of claim 11, wherein the plurality of suppressor chambers span a longitudinal length corresponding to at least 90% of a longitudinal length of the suppressor bore.

13. The fluid jet enhancement muzzle suppressor of claim 1, further comprising one or more baffles in each suppression chamber.

14. The fluid jet enhancement muzzle suppressor of claim 13, wherein the one or more baffles are independently shaped as a disc, a catenary or a hemisphere.

15. The fluid jet enhancement muzzle suppressor of claim 1, wherein each suppressor chamber radially envelops the suppressor bore or partially envelops the suppressor bore.

16. The fluid jet enhancement muzzle suppressor of claim 1, wherein the suppression chamber has a suppression chamber width (C.sub.w) and the suppressor bore has a bore diameter (B.sub.D) wherein 0.5C.sub.w/B.sub.D2 and/or a suppression chamber height C.sub.H, including 0.5C.sub.H/B.sub.D2.

17. The fluid jet enhancement muzzle suppressor of claim 1, wherein the propellant driven disrupter muzzle end corresponds to a distal end of a reverse velocity jet tamper (ReVJeT) adapter connected to a propellant driven disrupter.

18. The fluid jet enhancement muzzle suppressor of claim 1, wherein the propellant driven disrupter muzzle end is directly connected to the proximal end of the fluid jet enhancement muzzle suppressor.

19. The fluid jet enhancement muzzle suppressor of claim 1, wherein the propellant driven disrupter muzzle end is indirectly connected to the proximal end of the fluid jet enhancement muzzle suppressor with a disrupter barrel adapter having a distal end that is threaded for receiving a correspondingly threaded proximal portion of the suppressor and a proximal end for mounting to the distal end of the propellant driven disrupter.

20. A fluid jet propellant driven disrupter comprising: a disrupter barrel having: a breech end, a muzzle end; a barrel lumen extending between the breech end and the muzzle end, an inner barrel surface that defines the barrel lumen; and an outer barrel surface that opposably faces the inner barrel surface, wherein at least a distal portion of the disrupter barrel comprises: a suppressor chamber positioned between the inner and outer barrel surfaces; a plurality of passages that connect the barrel lumen with the suppressor chamber, wherein the plurality of passages are sized to allow gas to move from the barrel lumen to the suppressor chamber and minimize liquid movement from the barrel lumen to the suppressor chamber; wherein the outer barrel surface has a proximal region that is a continuous surface that radially isolates the disrupter barrel lumen from a surrounding environment and a distal region having one or more passages that fluidly connects the suppressor chamber to a surrounding environment, and wherein the distal region spans 50% or less of a longitudinal length of the barrel from the muzzle end.

21. A method of disrupting an explosive target, the method comprising the steps of: connecting the fluid jet enhancement muzzle suppressor of claim 1 to a disrupter; positioning an explosive blank cartridge in a breech end of the disrupter barrel; filling at least a portion of the barrel with a fluid projectile; exploding the explosive blank cartridge to propel the fluid projectile out of the barrel toward the explosive target; and temporarily trapping explosive gases in the suppressor chambers without substantial trapping of fluid to thereby dampen gas shock on a proximal end of the fluid projectile exiting the barrel, reduce a muzzle blast effect and reduce a jet reverse velocity gradient.

22. The fluid jet enhancement muzzle suppressor of claim 1, wherein the suppressor bore diameter is constant over a longitudinal length of the suppressor bore.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is an illustration showing a portion of a propellant driven disrupter, including the barrel, and disassembled components of an exemplary fluid jet enhancement adapter.

(2) FIG. 2 is an illustration showing the disrupter of FIG. 1 with a fluid projectile therein and the adapter of FIG. 1 operably connected to the disrupter.

(3) FIG. 3 is a partially cross-sectional illustration of the disrupter and adapter of FIG. 2, with the nut shown separately from the adapter for visual clarity.

(4) FIG. 4 is a cross-sectional illustration showing a portion of a muzzle portion of a disrupter barrel and an exemplary adapter having a taper.

(5) FIG. 5 is a cross-sectional illustration of the disrupter and adapter of FIG. 4, wherein the adapter further includes an accessory (e.g., a suppressor).

(6) FIG. 6 is a cross-sectional illustration showing a portion of a muzzle portion of a disrupter barrel and an exemplary adapter having recess features in the longitudinal region lumen.

(7) FIG. 7 is an illustration showing a portion of a disrupter with a fluid projectile therein, wherein the fluid projectile length is less than the disrupter barrel length.

(8) FIG. 8 is an illustration showing the disrupter and projectile of FIG. 7 with an exemplary fluid jet enhancement adapter operably connected thereto.

(9) FIG. 9 is a schematic of a rammer.

(10) FIG. 10 is a flow chart summary of a method for reducing a reverse jet velocity gradient in a liquid projectile ejected from a disrupter.

(11) FIG. 11 is a perspective view of a connector for securing any of the ReVJeT adapters provided herein to a disrupter barrel.

(12) FIG. 12 is a side view of the connector of FIG. 11, illustrating a gap between the top and bottom portions of the proximal end of the connector that may be securably tightened with fasteners that force the top and bottom portions against a disrupter barrel. The distal portion of the connector connects to the proximal end of the adapter.

(13) FIG. 13 is an end view of the connector of FIGS. 11-12.

(14) FIG. 14 illustrates a cut-away through section A-A of FIG. 13, with threaded end for rotationally connecting to a correspondingly threaded section of an outer surface of adapter proximal end. The proximal end of connector has a gap for receiving a disrupter barrel, where the connector proximal end can be tightly secured against an outer surface of the disrupter barrel.

(15) FIG. 15 illustrates an adapter connected to the connector, and ready to receive a disrupter barrel.

(16) FIG. 16 is a perspective view of a connector and adapter.

(17) FIGS. 17A and 17B are high speed video frame grabs of a conventional disrupter only and the same disrupter with an adapter of the present invention after fluid jet discharge, respectively. The pictures illustrate the improvement in jet characteristics when the adapter is used. The disrupter is a standard PAN setup, water filled 21.75 bore. The adapter has the same set-up, including same propellant load, but with a 10 ReVJeT adapter connected to the distal end of the disrupter barrel.

(18) FIG. 18 is a perspective view of a fluid jet enhancement muzzle suppressor 500 for use with a propellant driven disrupter. The connection proximal end 520 is shown having a connection mechanism 530 corresponding to threads.

(19) FIG. 19 is another perspective view of the fluid jet enhancement muzzle suppressor of FIG. 18.

(20) FIG. 20 is a side view of the fluid jet enhancement muzzle suppressor of FIGS. 18 and 19.

(21) FIG. 21 is a front view of the fluid jet enhancement muzzle suppressor of FIG. 20, as seen when looking at the connection proximal end along a longitudinal direction of the fluid jet enhancement muzzle suppressor. The front view of FIG. 21 is 90 rotated with respect to the side view of FIG. 20.

(22) FIG. 22A is a front view of the fluid jet enhancement muzzle suppressor of FIG. 20, as seen when looking at the suppressor distal end along a longitudinal direction of the fluid jet enhancement muzzle suppressor. The front view of FIG. 22A is 90 rotated with respect to the side view of FIG. 20 and is 180 rotated with respect to the front view of FIG. 21.

(23) FIG. 22B is a series of cross-section panels along a longitudinal direction of the fluid jet enhancement muzzle suppressor, for various exemplary fluid jet enhancement muzzle suppressors, wherein: (i) the fluid jet enhancement muzzle suppressor of the left panel has a suppressor chamber that radially enveloping the suppressor bore; (ii) the fluid jet enhancement muzzle suppressor of the middle panel has two or more suppressor chambers each of which partially, but not completely, radially envelopes the suppressor bore, where the more than one chambers are optionally disconnected from each other such that gases may not pass between different chambers; and (iii) the fluid jet enhancement muzzle suppressor of the right panel has a suppressor chamber that includes two or more baffles positioned radially about the suppressor bore.

(24) FIG. 23 is a cross-sectional side view of an exemplary fluid jet enhancement muzzle suppressor, for example as seen along cross-sectional cut line R as labeled in FIG. 22A.

(25) FIG. 24 illustrates another exemplary fluid jet enhancement muzzle suppressor. The top panel is an outer view with representative dimensions. The middle panel is a cross-section along the plane A-A of the top panel. The bottom right panel is a close-up view the region labeled B in the middle panel. The bottom left panel is a view of the distal end of the top panel.

(26) FIGS. 25A-25D are views of another exemplary fluid jet enhancement muzzle suppressor. FIG. 25A is a side view of the outer surface. FIG. 25B is a cross-sectional view of FIG. 25A. FIGS. 25C-25D are perspective views of FIG. 25A.

(27) FIGS. 26A-26D are exploded views of the device illustrated in FIG. 25A and illustrate the device may be formed from different individual components that can be separated to facilitate cleaning.

(28) FIG. 27A-27C illustrate a 10-chamber configuration, with tear-dropped shape ports at the two most distal chambers, chambers 9 and 10 (FIG. 27C). FIG. 27D illustrates a disrupter barrel adapter to connect a fluid jet enhancement muzzle suppressor to a distal end of a disrupter barrel.

(29) FIGS. 28A-28C illustrate various passage (also referred herein as gas port) shapes and patterns, with the two illustrated shapes that are slotted (FIGS. 28A-28B) and tear-drop shaped (FIG. 28C), and chamfered to reduce liquid (e.g., water) turbulence. For clarity, the suppressor bore with passage shapes are illustrated and the chambers are not illustrated.

DETAILED DESCRIPTION OF THE INVENTION

(30) In general the terms and phrases used herein have their art-recognized meaning, which can be found by reference to standard texts, journal references and contexts known to those skilled in the art. Referring to the drawings, like numerals indicate like elements and the same number appearing in more than one drawing refers to the same element. The following definitions are provided to clarify their specific use in the context of the invention.

(31) The term breech refers to the portion of the barrel of the propellant driven disrupter in which an explosive cartridge is positioned.

(32) Distal refers to a direction that is furthest from the breech or the explosive cartridge, or that is closest to the to-be-disrupted target. Proximal refers to a direction that is toward the explosive cartridge or that is furthest from the to-be-disrupted target.

(33) The term effective with regard to a fluid property such as viscosity, density, surface tension refers to an average measure of a property, including for a composite material that is formed of a combination of different materials. For example, a fluid mixture having multiple fluids and/or solid particles can be characterized as having an effective density or viscosity, which is a weighted average or bulk measure of the density or viscosity of the constituents of the fluid mixture. When applied to a fluid property, the term effective may refer to a mass-weighted average of the fluid and its constituents. When applied to a fluid property, the term effective may refer to a volume-weighted average of the fluid and its constituents. When applied to a fluid property, the term effective may refer to a bulk property of the fluid and its constituents.

(34) The term suspended with regard to solid particles in a fluid refers to a suspension, or a mixture of solid particles in a fluid wherein the solid particles are thermodynamically favored to precipitate or sediment out of the fluid solution. The suspension may appear uniform, particularly after agitation, (i.e., solid particles macroscopically evenly distributed in the fluid). The suspension is typically microscopically heterogeneous. In an embodiment, solid particles in a suspension are one micrometer or larger in diameter, including up to 1 cm, and any sub-ranges thereof. The solid particles of a suspension may be visible to the human eye. Solid particles in a suspension may appear uniformly mixed, particularly after agitation, but are undergoing sedimentation. The solid particles may remain suspended in the solution on short time scales (e.g., less than one minute) or indefinitely kinetically (i.e., in contrast to thermodynamically). As used herein, solid particles suspended in a fluid may refer to particles fully sedimented (e.g., lead shot particles settled to the bottom of a container with a highly viscous liquid such as syrup that hinders movement of the particles). As desired, a physical barrier may be positioned in the container so as to confine particles to a specific location, particularly for fluids through which the particles may otherwise readily traverse.

(35) The term dispersed in regard to solid particles in a fluid refers to a dispersion, or a microscopically homogenous, or uniform, mixture of solid particles in a fluid. Similarly to a suspension, a dispersion may be thermodynamically favored to segregate by sedimentation but wherein sedimentation is kinetically slowed or prevented. As used herein, a dispersion is a microscopically homogenous mixture having solid particles that are less than one micrometer in diameter. One example of a dispersion is a colloid (e.g., milk, tea, and coffee).

(36) The term jet length refers to the length of a column of fluid propelled out of a barrel muzzle. As a fluid is propelled out of the disrupter, it tends to disperse and undergo atomization. Thus, jet length may vary with time elapsed since leaving the muzzle and, consequently, vary with the distance from the muzzle.

(37) The term atomization refers to the dispersion of the propelled fluid into a cloud of fluid droplets. Atomization is one process that reduces the jet length and integrity. Atomized fluid is not included in the determination of jet length.

(38) The term jet length at impact refers to the jet length at the initial moment of impact between the fluid jet and the target.

(39) The term jet duration or fluid jet duration refers to the time until the fluid is completely atomized or dissipated and no jet, or collimated fluid, remains.

(40) The term jet impact duration refers to the total time the fluid jet imparts force or work on the target. The jet impact duration is a function of jet length at impact and jet velocity during impact.

(41) The term reverse velocity gradient refers to an explosively propelled fluid in a barrel disrupter having a fluid proximal end having a higher velocity than the fluid distal end, such that upon exit from the muzzle, there is an adverse impacting on one or more fluid jet parameters, resulting in premature jet breakdown and decrease in disruptive power. Provided herein are various fluid jet enhancement adapters and methods that can minimize the reverse jet velocity gradient, thereby improving one or more fluid jet parameters, including by an improvement of a fluid jet parameter by at least 10%, at least 20%, at least 50% or at least 100% compared to the same fluid projectile fired from the same or comparable disrupter but without any of the adapters disclosed herein.

(42) The term jet fluid velocity or fluid jet velocity is used broadly herein and refers to a characteristic average velocity, such as the average velocity of the entire fluid jet or the average velocity of a leading edge of the jet.

(43) As used herein, the terms fluid jet, jet fluid are used interchangeably to refer to the jet of fluid within the adapter lumen and/or at a point between the disrupter and the target after the fluid or projectile is propelled.

(44) Volumetric destruction refers to a disrupted, destroyed, or other physically altered volume of the target by the propelled and target impacted fluid jet. Destruction may be by physical release of material of the volume and/or functional destruction, such as release of a battery from a circuit, disruption of power circuits, or other circuit disruption, where a goal defeating an IED before an unwanted explosion occurs.

(45) As used herein, cap and plug are used broadly to refer to a physical seal of a container having fluid. The cap or plug may refer to a seal of a container encapsulating a HEET fluid for example, such that an encapsulated fluid may be positioned within the disrupter barrel. The cap or plug may refer to a seal applied within the disrupter barrel or at the muzzle end of the disrupter barrel to seal otherwise un-encapsulated fluid within the disrupter barrel (e.g., a fluid may be poured into the disrupter barrel and then a plug may be applied to seal the fluid within the barrel). A cap may refer to a factory-sealed end or to a material that is inserted into an open end, or a material that covers an open end. Any of the caps may be temporarily punctured to facilitate filling of a container to form, for example, a HEET fluid projectile.

(46) Operably connected refers to a configuration of elements, wherein an action or reaction of one element affects another element, but in a manner that preserves each element's functionality. For example, the adapter is operably connected to the muzzle end of the disrupter barrel such that a fluid projectile that is expelled from the disrupter barrel may enter the adapter's longitudinal region lumen without loss of pressure or fluid mass. The connection may be by a direct physical contact between elements. The connection may be indirect, with another element that indirectly connects the operably connected elements.

(47) The terms directly and indirectly describe the actions or physical positions of one component relative to another component. For example, a component that directly acts upon or touches another component does so without intervention from an intermediary. In contrast, a component that indirectly acts upon or touches another component does so through an intermediary (e.g., a third component).

(48) The term substantially equivalent refers to one or more properties of two or more elements that are within 10%, within 5%, within 1%, or are equivalent. For example, the diameter of an element A is substantially equivalent to the diameter of an element B if these diameters are within 10%, within 5%, within 1%, or are equivalent.

(49) The term radially isolates refers to an adapter barrel wall that prevents release of liquid in a radial direction, and instead forces all fluid out of the adapter distal muzzle end. Accordingly, substantially all fluid that enters the adapter lumen at the first (proximal) end ultimately exists the adapter lumen through the second (distal) adapter end.

(50) The term conventional disrupter refers to any commercially-available directional propellant-driven disrupter device having a barrel for ejecting a projectile (e.g., fluid jet) at a target explosive for disruption of said explosive, without an adapter described herein. Exemplary conventional disrupters include Percussion Actuated Non-Electric (PAN), Pigstick, Water Jet Disrupter Cannon, and similar disrupters.

(51) The term fluid jet parameter refers to a parameter useful in describing a characteristic or quality of a fluid jet expelled from the disrupter. Exemplary fluid jet parameters include, but are not limited to, jet integrity, jet length, jet impact duration on target, jet velocity, reverse velocity gradient, jet diameter, penetration depth, momentum on target, energy on target, shock pressure time-course, effective stand-off distance, barrier limit, component kill, and explosive impact dynamics. As described, the improvement in fluid jet parameter may be quantified, as appropriate, such as an improvement of at least 10%, 25%, 50% or 100% compared to an equivalent system without a ReVJet adapter.

(52) The term characteristic fluid jet diameter refers to a measure of a diameter of the fluid jet expelled from the barrel. It may be an average diameter over the discernable length of the fluid jet, or may be a diameter at a defined location over time, such as the distal end (e.g., the jet tip), the proximal end (e.g., the jet rear), or a mid-way point between the leading distal end and the trailing proximal end.

(53) Rarefaction is an art-recognized term referring to the reflection of a pressure wave at an interface due to a shock impedance mismatch. The term rarefaction waves refers to the pressure waves themselves that are moving back and forth in the fluid column and cause a reduction in the density (i.e., opposite of compression) of a fluid or other projectile. The waves cause a loss in fluid mass due to radial (hoop) dispersion and mixing of the fluid with air. The term rarefaction wave amplitude refers to the maximum change in density from the mean density.

(54) The term shock initiation event refers to an explosion, detonation, or other unwanted failure of the target caused by shock delivered by the projectile (e.g., fluid jet) onto the target (e.g., the target explosive device may detonate as a result of the imparted shock during transfer of energy from the fluid jet to the target device). The term probability of a shock initiation event refers to the statistical probability of the projectile (e.g., fluid jet) causing a shock initiation event, for a particular disrupter and projectile system. The probability of a shock initiation event is affected, for example, by the velocity, density, and cross-sectional area of the fluid jet, which is affected by barrel length and adapter length, for example.

(55) The term stand-off distance refers to the maximal distance from the target at which the fluid jet may be fired to achieve target disruption safely. The nominal stand-off distance refers to the distance resulting in optimum performance. Generally, the ReVJeT adapters provided herein facilitate an increase in stand-off distance without adversely impacting target disruption.

(56) In the following description, numerous specific details of the devices, device components and methods of the present invention are set forth in order to provide a thorough explanation of the precise nature of the invention. It will be apparent, however, to those of skill in the art that the invention can be practiced without these specific details.

(57) FIGS. 1-8 illustrate exemplary fluid jet enhancement adapters 200 connected to a propellant driven disrupter 100. The propellant driven disrupter 100 may be a conventional disrupter such as a PAN disrupter. Disrupter 100 includes a disrupter barrel 102 having a breech end 106 and a muzzle end 104. The muzzle end is the distal portion 105 of the disrupter barrel. Barrel 102 has a barrel lumen having a barrel lumen inner diameter 112. Barrel 102 has a muzzle end inner diameter 114 and a muzzle end outer diameter 116, defining a muzzle end outer surface 118. Barrel 102 has a barrel length 110. Disrupter 100 also includes a breech 108, which may be loaded with an explosive cartridge 122 (e.g., an explosive blank). Breech 108 may be a proximal portion of barrel 102 or a separate compartment that is operably connected to barrel 102. The lumen of barrel 102 may be loaded with a fluid projectile 300. Fluid projectile 300 may include a plug (or cap) 304 that retains the fluid of fluid projectile 300 at the distal end 306 of fluid projectile 300 within barrel 102. Proximal end 124 of fluid projectile may be similarly capped or sealed. Fluid projectile 300 may be prepared by filling at least a portion of the lumen of barrel 102 with one or more fluids (e.g., water), and then plugging the fluid within barrel 102 with plug 304, optionally using a rammer or ramrod such as rammer 234 (see FIG. 9). Alternatively, fluid projectile 300 may be a partially or fully encapsulated fluid projectile. Fully encapsulated fluid projectile 300, such as HEET fluid, may be loaded into the lumen of barrel 102 such that the wall of barrel lumen 102 does not physically contact a portion of the inner surface of barrel 102.

(58) FIG. 1 illustrates a disassembled exemplary adapter 200 and a portion of a propellant driven disrupter 100. FIG. 2 illustrates disrupter 100, including fluid projectile 300 therein, and adapter 200 assembled and operably connected to disrupter 100, and

(59) FIG. 3 illustrates a partial cross-section of the disrupter 100 and adapter 200 of FIG. 2. Adapter 200 of adapter length 201 includes a longitudinal region 202 that may be operably connected to barrel muzzle end 104 at the first end 203 of longitudinal region 202 (an operably connection is illustrated in FIG. 2). Longitudinal region 202 has a second end 204 where an expelled fluid projectile may exit adapter 200. Longitudinal region 202 has a length 205 between first end 203 and second end 204. Longitudinal region 202 has a longitudinal region lumen 206 having an inner surface 207. A longitudinal region wall 209 separates inner surface 207 from longitudinal region outer surface 208 by a wall thickness 226. Longitudinal region lumen 206 has a first end inner diameter 210 at first end 203 and a second end inner diameter 211 at second end 204.

(60) Adapter 200 may include a connector 213 at or extending from first end 203 of longitudinal region 202. When adapter 200 includes connector 213, adapter length 201 includes longitudinal region length 205 and connector length 215. The exemplary adapter 200 of FIGS. 1-3 includes a connector 213 for mounting ontoor otherwise operably connecting tomuzzle end 104 of barrel 102. At least a portion of connector 213 is a collet 222 which includes two kerf cuts 221. This connector 213 has outer surface 217 having threads or grooves 220. Connector 213 further includes a nut 224 with inner threads or grooves 225 which correspond to threads or groove 220 such that nut 224 may be rotationally tightened onto outer surface 217 of connector 213. Connector 213 further includes a lumen having an inner surface 216. Connector 213 is at proximal region 214 of adapter 200 and proximal region 214 has a resting proximal diameter 219A (inner) which may be greater than proximal lumen diameter 219B (inner). Resting proximal diameter 219A (inner) is selected such that adapter 200 may be secured to the barrel when nut 224 is tightened over at least a portion of collet 222 and outer surface 217, proximal region inner diameter (inner diameter of connector 213) is reduced from resting proximal diameter 219A (inner) to proximal lumen diameter 219B (inner), which provides a compression fit. The proximal lumen diameter 219B (inner) is substantially equivalent to or minimally greater than muzzle end outer diameter 116 in order to tightly (e.g., hand tight) accommodate a portion of muzzle end 104. This exemplary connector 213 forms a friction fit over muzzle end 104.

(61) Any of the adapters described herein may be compatible with a wide range of connection mechanism types and configurations. For example, adapter 200 may include connector 213 that is adapted to connect adapter 200 to a disrupter 100 via a screw-type connection such that connector 213 and muzzle end 104 having corresponding threads (e.g., connector 213 may be screwed onto and over muzzle end 104 having threads at outer surface 118 or connector 213 may be screwed into muzzle end 104 having corresponding threads at the inner surface of muzzle end 104). In another example, connector 213 may be configured to allow adapter 200 to be inserted into muzzle end 104 and held in place via friction. In yet another example, connector 213 may be configured to tightly fit over muzzle end 104 via friction and optionally further tightened via a clamp (i.e., no threads in this example). When adapter 200 is operably connected to disrupter 100, the connection is such that substantially no fluid is lost to a surrounding environment (air) 120 as fluid exits barrel 102 and enters adapter 200 and such that adapter 200 remains connected to barrel 102 after fluid projectile 300 is fully expelled from adapter 200. Adapter 200 may remain operably connected to barrel 102 after at least one, at least two, at least five, or at least ten uses of disrupter 100 (wherein use of disrupter 100 constitutes firing of a projectile). Connecter 213 may have one or more, two or more, three or more, or four or more kerf cuts. Any of the elements and/or portions of connector 213 may be formed of substantially the same material(s) as longitudinal region 202. Any of the elements and/or portions of connector 213 may be formed of different material(s) than longitudinal region 202 (e.g., nut 224, if used, may be formed of a different metal than connector 213 or longitudinal region 202). Optionally, an adhesive may be used between connector 213 and barrel 102.

(62) Alternatively, adapter 200 may be operably connected at first end 203 to muzzle end 104 via such that adapter 200 does not include connector 213. In another example, adapter 200 may be operably connected to muzzle end 104 via a tongue and groove type connection mechanism, wherein connector 213 is formed as a radially configured tongue and muzzle end 104 includes a corresponding radial groove, or vice versa. A clamp and/or an adhesive may be further used in the previous example to further increase tightness of fit.

(63) FIG. 4 illustrates an exemplary adapter 200 operably connected to barrel 102 at muzzle end 104. Adapter 200 is, for example, pressure fit by sliding connector 213 over muzzle end 104 and a clamp (not shown) may be tightened over connector 213 to increase tightness of fit. FIG. 4 shows adapter 200 having a taper 212. Taper 212 may be described by an angle (e.g., 1 or more, 5 or less, or between 1 and 5), a length, and/or a ratio of inner diameters (e.g., ratio of first end inner diameter to second end inner diameter). For visual clarity, FIG. 4 illustrates taper 212 by the difference in radii between the first end inner radius and the second end inner radius dimensions.

(64) Longitudinal region wall thickness 226 may be uniform or non-uniform over length 205 of longitudinal region 202. For example, wall thickness 226 is non-uniform where longitudinal region inner diameter changes while longitudinal region outer diameter remains unchanged. For example, wall thickness 226 is non-uniform where longitudinal region outer diameter changes while longitudinal region inner diameter remains unchanged (e.g., if outer surface 208/outer diameter is configured to include a taper such as illustrated in FIGS. 1-3). For example, wall thickness 226 is non-uniform where the inner and outer diameters of longitudinal region 202 both change by different amounts.

(65) The entirety of adapter 200 may be formed of a single material or combination of materials (e.g., entire adapter 200 is formed of stainless steel). Any one or a more elements of adapter 200 (e.g., connector 213 or nut 224) may be formed of a different material or different combination of materials than are other elements of adapter 200.

(66) For example, longitudinal region outer surface 208 may be at least partially formed of a different material than substantially the remainder of adapter 200. For example, outer surface 208 may include a partial or full coating, such as a coating configured to increase heat dissipation, formed of a different material than are other elements of adapter 200 (e.g., stainless steel). Adapter 200 may be uniformly or non-uniformly formed of one or more metals (e.g., stainless steel or aircraft aluminum), one or more ceramic materials (e.g., alumina), one or more polymer or plastic materials, carbon fiber, or of any combination of these.

(67) Longitudinal region length 205 may between 20% and 200% of fluid-projectile length 302. Length 205 may be empirically determined for any disrupter system according to disrupter 100 parameters (e.g., length and cartridge 122 characteristics) and/or fluid projectile parameters (e.g., composition). Fluid projectile length 302 may be substantially equivalent to barrel length 110 (e.g., FIGS. 2-3). Fluid projectile length 302 may be less than barrel length 110 (e.g., FIGS. 8-9). Additionally, for example, any of taper 212, wall thickness 226, and composition material(s) in adapter 200 may be empirically determined for any disrupter system according to disrupter 100 parameters, fluid projectile parameters (e.g., composition), and/or desired improvement in target disruption parameters (e.g., fluid jet length, impact pressure, reverse fluid jet velocity, etc.).

(68) FIG. 5 illustrates adapter 200 further including an accessory 230 and an accessory connector 233 at second end 204. For example, accessory 230 may be a Venturi tip, a suppressor, or a combination thereof. For example, FIG. 5 illustrates an accessory 230, such as a suppressor, connected to adapter 200 by accessory connecter 232. The suppressor may have a chamber between the inner lumen and outer surface and passages sized to allow high pressure gasses to enter the chamber, but substantially no fluid.

(69) FIG. 6 illustrates adapter 200 having recess feature 228 within longitudinal region 202. Recess features 228 may be fully or partially radially configured within the lumen of longitudinal region 202. Adapter 200 may include one or more recess features 228. Recess features 228 do not expose the lumen to the surrounding environment. In other words, recess features 228 are configured such that substantially none of the fluid of fluid projectile 300 exits adapter 200 except at second 204 (or, except through accessory 230, if present).

(70) FIG. 9 illustrates an exemplary rammer 234, the rammer having width 236 and length L, with the smaller diameter ramming body 237 configured to insert into lumen at a length L. Adapter 200 may include rammer 234 in order to control or adjust the fluid projectile length and/or apply plug 304 before and/or after adapter 200 is operably connected to barrel 102. The length, L, may be configured to be user-adjustable, including by a telescoping connection 235 of adjacent sections of ramming body 237, or between ramming body 237 and handle portion 238.

(71) The adapters described herein may include any combination of features and/or elements of adapters 200, including any of those illustrated in FIGS. 1-9 and FIGS. 11-16, as well as any of the functional benefits described above.

(72) FIG. 10 is a flow chart summary illustration an exemplary method 1000 for improving jet-fluid parameters such as reducing a reverse jet velocity gradient in a fluid jet projectile ejected from a disrupter. In optional step 1002, longitudinal region length 205 is selected based on fluid projectile length 302. Other elements beside longitudinal region 202 may be inseparable from adapter 200, in which cases selecting longitudinal length 205 means selecting adapter 200 having the desired or needed longitudinal region length 205 according to disrupter 100 parameters (e.g., length and cartridge 122 characteristics) and/or fluid projectile parameters (e.g., composition). In step 1004, adapter 200 is operably connected to muzzle end 104 of barrel 102 of adapter 100. An operable connection between adapter 200 and muzzle end 104 may include any one or a combination of compatible connection mechanisms, optionally via connector 213, which may optionally be the exemplary connector 213 illustrated in FIGS. 1-3 (e.g., having collet 222). In step 1006, at least a portion of barrel 102 is filled with fluid projectile 300. For example, step 1006 may include filling of a fluid into barrel 102, followed by plugging the fluid using plug 304, optionally employing a ramrod such as rammer 234. Alternatively, step 1006 may include inserting an encapsulated fluid projectile 300 such as a HEET fluid projectile into barrel 102. In optional step 1008, accessory 230 is operably connected to longitudinal region second end 204. For example, a suppressor is operably connected to longitudinal region second end 204 to reduce muzzle blast effect on a proximal portion of the fluid projectile exiting at the longitudinal region second end 204. Alternatively, the suppressor may be incorporated with the ReVJeT adapter instead of attaching to the adapter. In step 1010, fluid projectile 300 is propelled out of barrel 102, into longitudinal region 202 of adapter 100, and outer of longitudinal region second end 204 toward a target explosive device. In optional step 1012, a Venturi effect is exerted on the fluid projectile as it is propelled through longitudinal region lumen 206 and out of longitudinal region second end 204. In step 1014, an improved jet-fluid parameter is provided via use of adapter 200 with disrupter 100. See above for examples of jet-fluid parameter improvement.

(73) The invention can be further understood by the following non-limiting examples.

Example 1: ReVJeT Adapters for Disrupter Enhancement

(74) Any of the fluid jet enhancement adapters disclosed herein may be referred to as a Reverse Velocity Jet Tamper (ReVJeT) disrupter enhancer. The ReVJeT is used to improve effectiveness of propellant driven disrupters in the defeat of improvised explosive devices (IEDs). The ReVJeT stabilizes a fluid jet improving efficiency with respect to standoff, and improves target penetration and impulse. ReVJeT reduces the risk of shock initiation of explosives. ReVJeT makes it feasible to use disrupters to create breaching access in other types of targets such as walls, windows, doors, vehicle bodies, and windshields with minimal hazard to persons on either side of the breach zone.

(75) Fluid jets are used to defeat IEDs by penetrating barriers and, through inertial transfer, disable an IED. The ReVJeT is a tubular extension which can be attached to the muzzle of a fluid filled barrel that causes the jet tip to accelerate and the back end of the jet's acceleration to be hampered: the result is a normalized velocity over the jet length. The fluid jets of current systems are limited in jet free flight and quickly break up by atomization. The ReVJeT can improve fluid jet performance by up to 800% at greater standoffs. The ReVJeT may increase penetration into a target by at least 1.5 times at nominal standoffs because the fluid column remains intact and does work on the target longer. In one test method, the ReVJeT has shown to have similar penetration to explosively driven mass-focusing shaped charges. In addition, the ReVJeT reduces impact pressure with respect to time such that it will not, or is less likely to, shock initiate sensitive explosives, to include flash powder.

(76) The Percussion Actuated Non-electric (PAN) disrupter is the most widely used propellant driven disrupter used by public safety bomb technicians and explosive ordnance disposal (EOD) operators in the United States. The PAN and many similar disrupters can fire solid projectiles and also drive water at high velocity to penetrate barriers and transfer momentum to disable fuzing systems and open and disperse the contents of an IED. As a result, these gun-type disrupters are commonly referred to as water cannons. There are many disrupters on the market with varying barrel length and caliber (12 gauge is most common) and thus have different water column lengths and diameter. Some of these disrupters are designed with short barrels and it has been established they produce unstable water jets which atomize too quickly and are ineffective at defeating IEDs. They also require dramatically closer stand-off distances compared to full-size disrupters. The inventors have established the cause of the inefficiencies in disrupters, particularly short barreled disrupters.

(77) Generally, to load a disrupter, the fluid, most commonly water, is poured down the barrel and completely fills the barrel. The barrel is sealed by inserting plugs in the breech and muzzle. An explosive cartridge, typically a shotgun shell, is inserted into the breech. The explosive cartridge does not contain a projectile and is known as a blank cartridge. Blank cartridges can vary in strength, and increased strength cartridges cause higher jet velocities. The explosion produces rapidly expanding hot gases which pressurize the disrupter chamber and push the water out of the barrel at high velocity.

(78) Driving a fluid by explosively expanding gases results in several factors which cause a fluid jet to atomize that are not observed with jets produced by non-explosive systems such as in water fountains. The explosion in breech produces a shock wave that propagates down the water column. Due to shock impedance mismatches, the waves rarefact at the water-gas interfaces and move back and forth in the water column thus creating tensor and compressive stresses. As pressure waves collide inside the jet, they cause hoop stress on the water. When the column forms a jet outside the barrel, the pressure waves cause the water to expand radially and because water cannot withstand hoop stress it atomizes. High speed video reveals rings of atomized water spray propagating down the central axis of the disrupter jet.

(79) An additional factor which causes the jet to break up is due to the water jet reverse velocity gradient. This phenomenon was identified using flash X-ray imagery. Because the water behaves approximately as an inviscid fluid, the water is accelerated mostly only while it is in the barrel. The initial water coming out of the barrel is at low velocity and the water behind it is accelerated for a longer period in the barrel and is at higher velocity. The jetting water has a continuum or gradient of increasing velocity from the jet tip to tail. For simplicity of explanation and analytical modeling, the water column can be treated of as being made up of discrete water elements each traveling at increasing velocity as one moves rearward in the water column. The previous flash X-ray work showed the jet tip has a mushroom or jelly fish shape. It was thought that the jet tip mushrooming was due to air drag and the fluid-fluid interaction with air that eroded the jet from the front to the rear. The observed results revealed a growing jet tip velocity as the slower water is dispersed. Increasing the disrupter distance from the target, the impact pressure also increases. The impact pressure can be approximated to have a velocity squared dependence. If the pressures are too high, the precursor shock wave through the barrier or impact with the explosives can cause an explosive reaction inside the IED.

(80) One interpretation theorized that the rearward water would overtake the water in front of it and contribute to the increasing jet velocity. This is likely not the case as will be explained below.

(81) Computational modeling and previous flash X-ray shows that the jet length shrinks in free flight as the faster water overtakes the water in front of it. CTH modeling indicated the rearward water elements pushing on the water in front causes the water to atomize radially because it cannot withstand the hydrodynamic stress. Tracers in the model show the water in the rear does not overtake the water in frontrather it destroys the jet as it propagates. The consequence of a shrinking jet is the duration of loading is reduced and penetration within the target drops because penetration is proportional to jet length.

(82) The ReVJeT characterization reveals the fluid jet tip erosion and the characteristic jelly fish shape of the fluid tip is predominantly due to the reverse velocity gradient and not air drag. We propose each element of water pushes into the one in front and causes it to be pushed out of the way radially. High speed video shows the ReVJeT greatly reduces the jelly fish shape despite the fact that the fluid nose is moving at nearly double its velocity without ReVJeT. The theoretical effects of air drag on jet erosion is examined. The calculations only factor in air drag, and assumes a laminar flowing normalized water jet, the jet should propagate at least six times farther than the observed distance. If this calculation showed a distance similar to observation, then air drag would be an important consideration. We accordingly conclude that air drag erosion is not a major factor in the jet destabilization.

(83) There are two additional factors of note that contribute to fluid jet atomization. A Reynolds number calculation predicts that water flow within the barrel is highly turbulent and this turbulence causes an unstable jet outside the barrel. Without giving up velocity needed for work on a target, the only way to reduce the turbulence is to significantly reduce the barrel diameter. This is impractical because the loss of jet mass and diameter would cause a huge drop in impulse and displacement of material inside the bomb. The likelihood of the jet interacting with internal IED structures would be low and it would defeat the purpose of using a fluid for general disruption of IEDs. Furthermore, excessive velocities may occur if the same blanks were used. The last factor that will be discussed is the muzzle blast and shock due to the hot gases traveling faster than the fluid. It is obvious from high speed video that the muzzle blast further accelerates the rear of the jet and causes the end of the jet to fan out radially. Our data also indicates the muzzle blast also transmits a shock through the jet and negatively effects the jet tip.

(84) U.S. Pat. No. 6,896,204 B1 (Greene) proposes to retard the acceleration of the rear of a water column in order to preserve the jet at longer standoffs. Greene describes a disrupter adapter that contains gas ports at the junction with the barrel. The Greene adapter has an abrupt widening of the diameter at the zone containing the gas ports. The intent was to use the Venturi principle to slow down the water. A Reynolds number calculation would predict an increase in water turbulence caused by the larger diameter in this region. The ReVJeT, in contrast, does not have an abrupt change in diameter and does not have gas ports at the junction with the disrupter muzzle. Gas ports will cause a sudden drop in pressure which would dramatically cause a drop in disrupter performance at nominal standoffs because the average jet velocity is an important parameter in access and disablement of a bomb. Greene describes the adapter as having varied diameter and the length being equal to the water column. That design, however, would greatly reduce the average velocity of the water jet for a given blank cartridge and the length of the adapter is fixed and not tuned to the disrupter system. As explained below, there is an optimum ratio of ReVJeT length to fluid column length. The wrong ratio can be detrimental to disrupter performance and must be empirically determined for each disrupter system. The ReVJeT greatly reduces the reverse velocity gradient without sacrificing average jet velocity.

(85) A method of producing a ReVJeT system is to fill the entire disrupter barrel with an encapsulated fluid and then attach a ReVJeT adapter to the end of the barrel. The ReVJeT adapter is a tube with the same diameter as the disrupter barrel at the junction with the barrel and a length specific for the disrupter system. The tube extension allows the tip of the water column to accelerate under confinement and the back end of the water column's acceleration is limited by several variables which will be explained in the following paragraphs. The end result is a normalized water jet with a high average velocity that we have shown will outperform the same disrupter system without ReVJeT at any standoff and not cause shock initiation of common explosives found in IEDs. The disrupter without ReVJeT was shown to shock initiate some of these explosives. Three disrupter systems from different manufacturers are used in our tests. The disrupters had varying fluid column lengths and used different blank cartridges.

(86) The sustained mass of the flowing water column inside the combined barrel and ReVJeT adapter causes a lower velocity at the jet rear due to the velocity's inverse square root dependence with respect to mass inside the extended barrel. Furthermore, water is not truly inviscid so the water that has exited the barrel is contributing to the drop in acceleration.

(87) The internal barrel pressures drop with distance from the breech due to heat loss, gas expansion and fluid shear forces. Cooling of the hot expanding gases occurs through conductive heat transfer with the barrel and ReVJeT. The added ReVJeT shear forces have a greater influence toward the rear of the fluid column. As the gas expands from the breech, the ideal gas law predicts the work on the fluid column decreases approximately logarithmically. The opposing fluid shear stress further reduces the work on the fluid column. The ReVJeT adapter causes additional shear stress which is a function of the fluid viscosity and is proportional to the fluid velocity. Since the fluid at the rear is moving more quickly and is interacting with the disrupter and ReVJeT walls longer, the shear force produces negative feedback on rear of the fluid to drop the pressure and slow its flow. The pressure loss is directly proportional to the length of the barrel plus the ReVJeT extension as predicted by the Darcy-Weisbach equation. Additional pressure loss may be caused by fluid adhesion with the barrel walls. In the case of HEET fluids which can be composed of long chain polymers often have strong adhesive properties. The result of these forces is a normalized velocity over the jet length with a critical average velocity that enables the jet to perforate common IED casings/containers and provides the necessary impulse to disperse the IED's explosives and destroy internal components. Further, the normalized velocity does not ramp up the impact pressure as previously noted for jets not tamped by ReVJeT. Explosive impact dynamics tests with ReVJeT showed no reaction with common IED explosives including flash powder.

(88) Another additional benefit of ReVJeT is the damping out of the rarefaction waves. The barrel extension causes the fluid to remain confined for a longer period of time. During the fluid's confinement, the rarefaction waves reflect back and forth through the water column and due to energy losses the amplitude should decrease exponentially, similar to a pressure wave produced in a rod. Some of the pressure wave amplitude damping may occur due to barrel harmonics and the impedance mismatch of a dissimilar metal used to make the ReVJeT. We demonstrate the ReVJeT's ability to eliminate the rarefaction waves. In these experiments, we use a viscous fluid in place of water and removed a percentage of the fluid column from the barrel to produce the ReVJeT behavior. The fluid jet showed almost laminar flow, no jelly fish shaped tip, and no rarefaction waves as it exited the barrel.

(89) Alternative methods can be used to improve some fluid jet parameters. A simple method is not filling the entire barrel with fluid, thereby leaving a distal portion of barrel void of fluid. Another option is to combine a smaller extension and reduce the amount of fluid removed from the barrel to create the required optimum length of empty tube. In both methods, a ram rod can be used to quickly displace the desired amount of water and also seat the muzzle plug. The disadvantage of these methods is a shorter jet length, however, we have shown the mass reduction will cause higher average velocities for a given blank cartridge and enable the jet to penetrate thicker or tougher material barriers.

(90) The ratio of tube length to fluid column length is important to maintain disrupter performance for a given fluid, disrupter barrel, and cartridge. We empirically determine that the optimal ReVJeT adapter length can be between 40% and 150% of the fluid column. A typical full-sized disrupter can have a fluid column as long as 22 and short barreled disrupters can have fluid column lengths as short as 7. The short barreled disrupter water jets will experience considerably higher reverse velocity gradients because they use cartridges of the same strength as the full-sized disrupters. Regardless of the disrupter used, the fluid closer to the muzzle end will always have an initial velocity close to zero. The reduced projectile mass will cause the velocity of the fluid column rear to be considerably higher than a full-sized disrupter which holds up to 2.5 times the mass. The rarefaction waves are also more violent in short barreled disrupters. The result is the necessity for a higher ratio of ReVJeT to fluid column length for smaller disrupter systems in order to normalize the water velocity. The optimal lengths for the ReVJeTs are determined through testing. We empirically determine that the non-optimal ratio of ReVJeT length to fluid column length can be detrimental to the fluid jet's performance with respect to impulse, barrier penetration, and cavitation. The ReVJeT is optimized to the specific disrupter system defined by the projectile fluid, blank cartridge, and barrel dimensions.

(91) The ReVJeT can be further enhanced by slightly tapering the barrel diameter or by putting specialized tips on its end. A slight taper in inner diameter would produce a Venturi effect and increase the average jet velocity. As an option, the ReVJeT can have a threaded end to connect different tips to produce a variety of effects. For example, a Venturi tip can be attached to the ReVJeT extension instead of tapering its diameter to increase jet velocity, and more importantly jet length for a given volume of fluid. This would be of benefit for shorter fluid columns. A suppressor can be placed on the end of the ReVJeT to reduce muzzle blast effects on the rear of the exiting jet.

Example 2: Connecter

(92) Other connecter 213 configurations are illustrated in FIGS. 11-16. The connectors may be used to connect any of the adapters described herein to a conventional disrupter. FIGS. 15-16 illustrate connecter 213 connected to adapter 200.

(93) Connector proximal end 400 is configured to connect to disrupter barrel outer surface. Connector distal end 410 is configured to connect to adapter threaded outer surface. This is illustrated in FIG. 14. The connector may have a connector clamp 420 to facilitate reliable tight-fit against the disrupter outer barrel surface distal end. This tight fitting can be reliably, efficiently, and quickly achieved by use of fasteners (not shown) through connector fastener passages 430 that, when tightened, decreases connector clamp gap 440, to provide compressive fitting between adapter and disrupter barrel outer surface. In this manner, no special machining of disrupter barrel outer surface is required to retrofit disrupter barrel with any of the adapters provided herein.

(94) Connecter distal end 410 may have threads 450 on an internal surface 460 to rotationally mate with adapter having corresponding threads on an outer surface of the adapter proximal end.

Example 3: ReVJeT Improved Fluid Jet Parameter

(95) FIGS. 17A-17B are photographs that explicitly illustrate improved fluid jet characteristics when an adapter is connected to the disrupter (FIG. 17B) compared to the same disrupter without the disrupter (FIG. 17A labelled Standard), with the water expelled from the muzzle and traveling in a left to right direction toward target 170. The ReVJeT has more well-defined jet column, with a much less atomization and rarefaction wave indication. The jet-tip of FIG. 17B remains well-defined, and continues to travel in a mainly longitudinal direction, providing improved barrier-defeating capability compared to the dispersing fluid jet tip illustrated in FIG. 17A. The improved jet from the ReVJeT accordingly provides better work on target with correspondingly improved penetration and work in a target interior. Functionally, this results in rapid and reliable disruption of the target interior and associated reliable disarming of explosive devices such as IEDs.

(96) One reason for the fluid-jet improvement is the change in fluid velocity gradient between the distal and proximal jet ends. Without the adapter of the instant invention, the rear of the jet is at least about 155% faster or 128% faster than the front of the jet. In contrast, use of ReVJeT adapter constrains the rear of the jet to be no more than about 15% faster than the front, with even smaller differences achieved by appropriate selection of HEET fluid, including having solid particles suspended in the proximal portion of the fluid.

Example 4: Muzzle Blast Reduction

(97) Provided herein are various devices and methods that provide muzzle blast reduction, including without unduly impacting fluid jet characteristics, including the reverse velocity jet disruption described in the previous examples. A muzzle blast suppressor provided herein may be used or incorporated into a wide range of disrupter barrels. For example, a muzzle blast suppressor may be configured to connect to a ReVJet, including any of the ReVJet described herein and in U.S. patent application Ser. No. 15/896,760 filed Feb. 14, 2018, which is specifically incorporated by reference herein.

(98) Alternatively, a muzzle blast suppressor may itself be incorporated as an integral part of ReVJeT, with corresponding retrofit to a disrupter barrel end. Alternatively, the suppressor and ReVJeT aspects may be integrally incorporated into a disrupter, such that no separate pieces need be connected to the disrupter barrel in order to achieve the benefits of ReVJeT and the muzzle blast suppression described herein.

(99) FIGS. 18-28C illustrate a fluid jet enhancement muzzle suppressor 500. The suppressor 500 may be for use with a propellant driven disrupter 100 (illustrated in FIG. 1, for example) or a ReVJet (e.g., adapter of Ser. No. 15/896,760) 200 connected thereto, the fluid jet enhancement muzzle suppressor comprising: a connection proximal end 520 having a connection mechanism 530 configured to operably connect to a propellant driven disrupter muzzle end 104; a suppressor distal end 560; a suppressor bore 570 extending between the proximal end and the distal end; an inner suppressor surface 580 that defines the suppressor bore; an outer suppressor surface 590 opposably facing the inner suppressor surface, wherein a suppressor wall thickness 600 is the difference between the outer and inner radii, and may contain one or more suppressor chambers 610 positioned between the inner and outer suppressor surfaces; a plurality of passages 620 that connect the suppressor bore with the suppressor chamber, wherein the plurality of passages are sized to allow gas to move from the suppressor bore to the suppressor chamber and minimize liquid movement from the suppressor bore to the suppressor chamber; wherein the outer suppressor surface is a continuous surface that radially isolates the suppressor chamber from a surrounding environment; and wherein the suppressor bore has a diameter 630 at the connection proximal end that is substantially equivalent to a propellant driven disrupter muzzle end diameter.

(100) The fluid jet enhancement muzzle suppressor may have a connection mechanism that comprises a threaded end 640 configured to rotationally connect to a corresponding threaded end of a disrupter barrel or a disrupter barrel adapter.

(101) The suppressor has a plurality of passages for receiving expanding gas during and after explosive cartridge ignition, thereby suppressing muzzle blast. The passages, however, are specially configured to minimize fluid loss and unwanted effects on the fluid projectile, such as avoiding undue reduction in fluid jet tip velocity.

(102) The plurality of passages have an average diameter that is less than or equal to 3/16, or less than or equal to . The plurality of passages may be described by a spatial density, such as a spatial density of between 2 passages cm.sup.2 to 8 passages cm.sup.2.

(103) The plurality of passages may have a uniform spatial distribution over a portion of the suppressor surface, such as at least 90% of the inner suppressor surface. For example, a proximal portion of the suppressor may not have passages, and instead the passages confined to the distal 90% or less of the inner suppressor surface. Uniform, in this aspect, refers to a spatial density that deviates by less than 20% over a defined surface. Alternatively, the plurality of passages may have a non-uniform spatial distribution, wherein there is a gradient of passage density, or the passages are at a specified distance from the proximal end. The passage spacing may be radially symmetric on the surface at a specified distance up to 90% from the proximal end. The passage spacing with radial symmetry may be a repeated pattern at multiple positions along the length of the suppressor bore at specified distances from the proximal end.

(104) The passages described herein are compatible with a range of passage cross-sectional shapes, orientation, angles, locations and patterns. The plurality of passages may spatially aligned.

(105) The plurality of passages may be sized so that less than 1% by mass of a disrupter fluid enters the suppressor chamber or a plurality of suppressor chambers.

(106) The suppressors described herein may be further described in terms of chambers 610 to which the passages terminate. There may be a single or a plurality of chambers, including chambers having one or more baffles disposed therein.

(107) The plurality of suppressor chambers may span a longitudinal length corresponding to at least 90% of a longitudinal length 650 of the suppressor bore 570.

(108) One or more baffles 660 may be positioned in each suppression chamber

(109) Each suppressor chamber may radially envelop the suppressor bore or may partially envelop the suppressor bore.

(110) The fluid jet enhancement muzzle suppressor may be described in terms of a suppression chamber width (C.sub.w) 670 and a bore diameter (B.sub.D) 675, such as 0.5C.sub.w/B.sub.D2.

(111) The fluid jet enhancement muzzle suppressor may be described in terms of a suppression chamber height (C.sub.H) 672, and a bore diameter (B.sub.D), such as 0.5C.sub.H/B.sub.D2.

(112) The suppressor may be connected to a ReVJeT adapter. For example, the propellant driven disrupter muzzle end may correspond to a distal end of a ReVJeT adapter connected to a propellant driven disrupter, including a ReVJeT adapter as described in U.S. patent application Ser. No. 15/896,760 filed Feb. 14, 2018, which is specifically incorporated by reference herein.

(113) The suppressor may be connected to a disrupter, such as a PAN. For example, the propellant driven disrupter muzzle end corresponds to a distal end of a propellant driven disrupter.

(114) The suppressor may be integral with the disrupter, such as manufactured with the disrupter so breech end feeds directly to the suppressor proximal end. Accordingly, a fluid jet propellant driven disrupter may comprise: a disrupter barrel 570 having: a breech end, a muzzle end; a barrel lumen extending between the breech end and the muzzle end, an inner barrel surface 580 that defines the barrel lumen; and an outer barrel surface 590 that opposably faces the inner barrel surface, wherein at least a distal portion of the disrupter barrel comprises: a suppressor chamber 610 positioned between the inner and outer barrel surfaces; a plurality of passages 620 that connect the barrel lumen with the suppressor chamber, wherein the plurality of passages are sized to allow gas to move from the barrel lumen to the suppressor chamber and minimize liquid movement from the barrel lumen to the suppressor chamber; wherein the outer barrel surface is a continuous surface that radially isolates the suppressor chamber from a surrounding environment. Effectively, this equivalent to the suppressor of FIG. 18 corresponding to the disrupter barrel, with the proximal end corresponding to a breech.

(115) Any of the suppressors may provide a means for a user to change or control the plurality of passages 620 that connect the suppressor bore with the suppressor chamber. In this manner, different degrees of muzzle blast reduction may be reliably achieved. A variety of means are available to provide for control of the passages. For example, a tube may thread in and out of the suppressor. In this manner, an operator may choose to not have any passages, thereby providing a standard ReVJeT without suppression characteristics.

(116) FIG. 24 is one example of a suppressor having one suppressor chamber. Of course, multiple chambers may be used, including as illustrated in FIGS. 27A-27C (illustrating ten suppressor chambers 610, each radially enveloping the bore). Adjacent chambers can be separated by perforated baffles 2610 (see, e.g., FIG. 26A-26D). Slots may be positioned in the outer suppressor surface, such as in a symmetrical configuration about the longitudinal axis. The slots 2620 illustrated in FIG. 24 are 0.06 wide by 0.75 long. The number of slots associated with a chamber may be between 5 and 7. As described, additional chambers and/or slots may be incorporated into the suppressor.

(117) FIGS. 25A-25D are additional views of the suppressor 2500 of FIG. 24, and in combination with FIGS. 26A-26D illustrate the various individual components, including bore with gas ports, perforated baffles, chamber sleeve, barrel clamp, sleeve end caps and locking nut. The gas ports can have a variety of shapes. The two illustrated are slotted (0.061FIGS. 25B and 26A-26D) and tear drop shaped (0.18751FIG. 27C). The ports walls can be chamfered (FIG. 28A-28C) to reduce water turbulence. The ports can be distributed symmetrically radially to form a set. A port set may be at specific longitudinal locations centered under a chamber. There can be multiple port sets. The outer barrel surface has a proximal continuous surface 2565 that radially isolates the disrupter barrel lumen 2540 from the surrounding environment 2580. The distal portion or region 2560 of the barrel has one or more passages 620 that fluidly connect to a chamber 610 and one or more passages (e.g., slots) 2510 that fluidly connects the suppressor chamber 610 to surrounding environment 2580. Various longitudinal distances 650 2560 2565 are illustrated in FIG. 28B, including for the suppressor bore, distal portion, and proximal portion, respectively.

(118) Confining the gas exchange to the distal portion, but some distance to the MBR muzzle, provides improved performance. In this manner, the pressure drop has to occur late in the jetting process so the water velocity is not slowed. The size of the chamber(s) is another factor. Too much chamber volume causes a drop in performance. It is a delicate balance between water stability and gas flux with respect to time. Some water needs to be in the barrel when gas exchange occurs to force the gases into the chambers. Concurrently, water needs to normalize with respect to velocity before it hits the ports to prevent radial expansion of water into the ports. The port shape, size, and in particular, the chamfering reduces turbulence in the water. The results indicate loss of water density due to turbulence that is prevented by switching from circular holes to tear drops and slots. An approximate 40% jump in penetration is achieved compared to ReVJeT without the muzzle suppressor.

(119) The chamber sleeve is sealed with the end caps. The number of baffles can vary and they can be positioned at different points along the longitudinal axis.

(120) The suppressor can have an approximately 3 long chamber sleeve with three chambers nearest the distal end of the suppressor. As discussed, any number of chambers may be used, including one (FIG. 24). The exploded views (FIGS. 26A-26D) illustrate the individual components and how they may position together. Suppressors may have either two tear drop port sets at chamber positions 9 and 10 (distal end) or a slotted port set at position 10. These configurations provide a significant increase in penetration compared to the standard ReVJeT adapter.

(121) FIGS. 27A-27C illustrate a chamber sleeve comprising a plurality (e.g., 10) of 1 wide rings that couple with the perforated baffles and are stacked to form a complete chamber network. FIG. 27D illustrates a connector 2700, with one end configured for rotational connection to a proximal end of the suppressor and the other end for clamping to the distal end of a disrupter barrel. This is one example of a connector that is useful for retrofitting a conventional disrupter with any of the suppressors provided herein.

(122) All the components can be separated so that the suppressor can be cleaned.

(123) Also provided herein are methods of disrupting an explosive target. The method may comprise the steps of: providing any of the fluid jet enhancement muzzle suppressor disrupters herein (e.g., integrated disrupter with muzzle suppression made by a manufacturer), or connecting any of the fluid jet enhancement muzzle suppressors to a disrupter (e.g., retrofit); positioning an explosive blank cartridge in a breech end of the barrel; filling at least a portion of the barrel with a fluid projectile; exploding the explosive blank cartridge to propel the fluid projectile out of the barrel toward the explosive target; and temporarily trapping explosive gases in the suppressor chambers without substantial trapping of fluid to thereby dampen gas shock on a proximal end of the fluid projectile exiting the barrel, reduce a muzzle blast effect and reduce a jet reverse velocity gradient.

STATEMENTS REGARDING INCORPORATION BY REFERENCE AND VARIATIONS

(124) All references throughout this application, for example patent documents including issued or granted patents or equivalents; patent application publications; and non-patent literature documents or other source material are hereby incorporated by reference herein in their entireties, as though individually incorporated by reference, to the extent each reference is at least partially not inconsistent with the disclosure in this application (for example, a reference that is partially inconsistent is incorporated by reference except for the partially inconsistent portion of the reference).

(125) The terms and expressions which have been employed herein are used as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding any equivalents of the features shown and described or portions thereof, but it is recognized that various modifications are possible within the scope of the invention claimed. Thus, it should be understood that although the present invention has been specifically disclosed by preferred embodiments, exemplary embodiments and optional features, modification and variation of the concepts herein disclosed may be resorted to by those skilled in the art, and that such modifications and variations are considered to be within the scope of this invention. The specific embodiments provided herein are examples of useful embodiments of the present invention and it will be apparent to one skilled in the art that the present invention may be carried out using a large number of variations of the devices, device components, methods and steps set forth in the present description. As will be obvious to one of skill in the art, methods and devices useful for the present embodiments can include a large number of optional device components, compositions, materials, combinations and processing elements and steps.

(126) Every device, system, combination of components or method described or exemplified herein can be used to practice the invention, unless otherwise stated.

(127) When a group of substituents is disclosed herein, it is understood that all individual members of that group and all subgroups, including any device components, combinations, materials and/or compositions of the group members, are disclosed separately. When a Markush group or other grouping is used herein, all individual members of the group and all combinations and subcombinations possible of the group are intended to be individually included in the disclosure.

(128) Whenever a range is given in the specification, for example, a number range, a flow-rate range, a size range, a pressure range, a velocity range, a time range, or a composition or concentration range, all intermediate ranges and subranges, as well as all individual values included in the ranges given are intended to be included in the disclosure. It will be understood that any subranges or individual values in a range or subrange that are included in the description herein can be excluded from the claims herein.

(129) All patents and publications mentioned in the specification are indicative of the levels of skill of those skilled in the art to which the invention pertains. References cited herein are incorporated by reference herein in their entirety to indicate the state of the art as of their publication or filing date and it is intended that this information can be employed herein, if needed, to exclude specific embodiments that are in the prior art.

(130) As used herein, comprising is synonymous with including, containing, or characterized by, and is inclusive or open-ended and does not exclude additional, unrecited elements or method steps. As used herein, consisting of excludes any element, step, or ingredient not specified in the claim element. As used herein, consisting essentially of does not exclude materials or steps that do not materially affect the basic and novel characteristics of the claim. In each instance herein any of the terms comprising, consisting essentially of and consisting of may be replaced with either of the other two terms. The invention illustratively described herein suitably may be practiced in the absence of any element or elements and/or limitation or limitations, which are not specifically disclosed herein.

(131) One of ordinary skill in the art will appreciate that compositions, materials, components, methods and/or processing steps other than those specifically exemplified can be employed in the practice of the invention without resort to undue experimentation. All art-known functional equivalents, of any such compositions, materials, components, methods and/or processing steps are intended to be included in this invention. The terms and expressions which have been employed are used as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding any equivalents of the features shown and described or portions thereof, but it is recognized that various modifications are within the scope of the invention claimed. Thus, it should be understood that although the present invention has been specifically disclosed by exemplary embodiments and optional features, modification and variation of the concepts herein disclosed may be resorted to by those skilled in the art, and that such modifications and variations are considered to be within the scope of this invention as defined by the appended claims.

(132) It must be noted that as used herein and in the appended claims, the singular forms a, an, and the include plural reference unless the context clearly dictates otherwise. Thus, for example, reference to a layer includes a plurality of layers and equivalents thereof known to those skilled in the art, and so forth. As well, the terms a (or an), one or more and at least one can be used interchangeably herein. It is also to be noted that the terms comprising, including, and having can be used interchangeably. The expression of any of claims XX-YY (wherein XX and YY refer to claim numbers) is intended to provide a multiple dependent claim in the alternative form, and in some embodiments is interchangeable with the expression as in any one of claims XX-YY.

(133) Unless defined otherwise, all technical and scientific terms used herein have the same meanings as commonly understood by one of ordinary skill in the art to which this invention belongs. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, the preferred methods and materials are described.