METHOD OF PROFILING OPENINGS OF ELEMENTS OF MECHANICAL SYSTEM FOR GENERATING OPTIMAL PRESSURE WAVES IN ELASTIC FLUIDS

Abstract

A method of and for optimizing pressure waves in fluids and profiling openings of elements of mechanical system to optimize systems, is provided. The method aids in the generation of pressure waves with predetermined waveform in elastic fluids and can be used to increase the energy efficiency in the pipeline technologies for the transportation of flowable media, one-phase and multi-phase, homogeneous, and heterogeneous media; powders, disperse mixtures; and technologies of forced extraction of liquids from capillary porous saturated media. Wherein, in the use of the method, changing a value of at least one of the parameters of the generating waves consisting of the shapes, sizes and single-position location of surfaces profiles of openings, amplitude, frequency, waveform, and the pressure difference (P.sup.+P.sup.) measured on the pump of generating compression and rarefaction pressure waves so, that an energy efficiency of a process of generating pressure waves determined by minimal value of the specific ratio and therefore a maximum energy efficiency of the interaction of the specific wave energy with the elastic fluid flow, is optimized.

Claims

1. A method of optimizing a value of at least one characteristic of an elastic fluid flow in a mechanical system for the moving of elastic fluid flows through conduits, with respect to energy efficiency of the flow process of the elastic fluid, comprising the steps of: providing a mechanical system comprising: a controlled drive; a first housing having an inner chamber formed with a first end cap and a second end cap held in a generally parallel configuration to each other and rigidly connected to a shaft of the controlled drive so that it is rotatable, the first housing having a first wall, having an inner surface and an outer surface and a first longitudinal end and a second longitudinal end and a first lateral end and a second lateral end, and an opening defined in the first wall, the first wall being connected to the first end cap and the second end cap, respectively at its first longitudinal end and its second longitudinal end, the first lateral end being joined to the second lateral end to form, with the first end cap and second end cap, a container, the first housing having an output connected to a first pipe, wherein, the inner chamber of the housing and the first pipe form together a first volume filled with elastic fluid exposed to an under pressure; a second housing having an inner chamber, within which the first housing is placed, the second housing being fixed from rotation and formed with a third end cap and a fourth end cap held in a generally parallel configuration to each other, a second wall having an inner and outer surface, the second wall having a first longitudinal end and a second longitudinal end and a first lateral end and a second lateral end, and an opening defined in the second wall, the second wall being connected to the third end cap and the fourth end cap, respectively at its first longitudinal end and its second longitudinal end, the first lateral end being joined to the second lateral end to form, with the third end cap and fourth end cap, a container, and an opening defined therein, the inner surface being located equidistantly from the outer surface of the first wall of the first housing when the first housing is placed within the second housing, the second housing having an input connected to a second pipe, the second housing and the second pipe form together a second volume filled with the first housing and an elastic fluid exposed to an over pressure; the axis of symmetry of the first housing and the second housing coinciding with the axes of rotation of the shaft of the controlled drive; wherein the mechanical system comprises a pump and a pressure waves generator configured for generating longitudinal pressure waves by rotating the first housing within the second housing creating an intersection of the surface of a cross-sectional opening in the first wall with the surface of a cross-sectional opening in the second wall during the rotating motion of the first wall relatively to the second wall by the drive, and for providing for the propagating of the generated waves through elastic fluid flow though conduits; generating pressure waves in elastic fluid by using the pressure wave generator; evaluating geometrical sizes of the first wall; providing a shape of a profile of a cross-sectional opening in the first wall of the inner chamber and providing the sizes of a profile of a cross-section opening in the first wall; evaluating geometrical sizes of the second wall; providing a shape of a profile of a cross-section opening in the second wall of the inner chamber and providing sizes of a profile of a cross-section opening in the second wall; providing the single-position location of the surface of the cross-section opening in the first wall of the inner chamber and of the surface of the cross-section opening in the second wall of the inner chamber so, that during the rotating of the first wall relatively to the second wall there is provided a periodically intersection of the surfaces of cross-sectional openings which forms a common surface between the first volume and the second volume with changeable shape and sizes depending on the intersected surfaces of profiles of the openings whose shape and sizes of the common surface are changing periodically and univocal versus time by a determined law; increasing the common surface from zero to the maximal value during a front time of each period; decreasing the common surface from the maximal value to zero during a back time of each period; providing a periodic connection of the first volume with the second volume through the common surface; generating simultaneously a compression pressure wave and a rarefaction pressure wave on the common surface; providing an amplitude of generating compression pressure wave and a rarefaction pressure waves in correspondence with the amplitude of the common surface and values of over pressure and under pressure; providing a frequency of generating compression pressure waves and a rarefaction pressure waves in correspondence with the frequency of the common surface; providing a waveform of generating compression pressure wave and rarefaction pressure waves in correspondence with the form of the common surface and values of over pressure and under pressure; providing the propagating of generating compression pressure waves through elastic fluid in the first volume, providing the propagating of generating rarefaction pressure waves through elastic fluid in the second volume; controlling an average value of a total specific energy of the elastic fluid flow by using a difference between over pressure and under pressure of the first volume and the second volume; evaluating of specific average value of a wave energy of pressure waves propagating and interacting with the elastic fluid flow during a period considering a density, viscosity and compressibility of the fluid flow; evaluating of a specific value of a ratio of an average value of specific wave energy of generating pressure waves propagating and interacting with the elastic fluid flow during a period and an average value of a total specific energy of the elastic fluid flow; changing a value of at least one of the parameters of the generating waves consisting of the shapes, sizes and single-position location of surfaces profiles of cross-section openings, amplitude, frequency and waveform of generating compression and rarefaction pressure waves so, that an energy efficiency of a process of generating pressure waves determined by minimal value of the specific ratio and therefore a maximum energy efficiency of the interaction of the specific wave energy with the elastic fluid flow is optimized.

2. The method as defined in claim 1, further providing the sizes of the first wall of the first housing and of the second wall of the second housing and such shape and sizes of the profile of a cross-sectional opening and single-position location of the profile in the first wall of the first housing and a shape and sizes of a profile of a cross-sectional opening and single-position location of the profile in the second wall of the second housing which causes the generation of pressure waves by the symmetrical law of change of pressure versus time.

3. The method as defined in claim 1, further providing the sizes of the first wall of the first housing and of the second wall of the second housing and such shape and sizes of the profile of a cross-sectional opening and single-position location of the profile in the first wall of the first housing and a shape and sizes of a profile of a cross-sectional opening and single-position location of the profile in the second wall of the second housing which causes the generation of pressure waves by the asymmetrical law of change of pressure versus time.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0035] FIG. 1 is perspective view of an example of a mechanical system configured for generating pressure waves in elastic fluids.

[0036] FIG. 2 is a schematic representation of an example of the mechanical system of FIG. 1 in place in a pipeline.

[0037] FIG. 3 is a cross-sectional view of the axial section of mechanical system for generating pressure waves in elastic fluids, taken along the line A-A of FIG. 1.

[0038] FIG. 4 is a schematic mapping of a part of the outer cylindrical fixed wall on a plane surface, comprising the single-position location of the surface of profile of cross-section of the opening.

[0039] FIG. 5 is a schematic mapping of the inner cylindrical movable wall on a plane surface, comprising the single-position location of the surface of profile of cross-section of the opening.

[0040] FIG. 6 is a schematic mapping of the outer cylindrical fixed wall and inner cylindrical movable wall on a plane surface, showing the relative single-position location of the surfaces of profiles of a cross-sections of openings, >.

[0041] FIG. 7 is a chart of outer cylindrical fixed and inner cylindrical movable walls on a plane surface, comprising the relative single-position location of profiles of the surfaces of cross-sections of openings, =.

[0042] FIG. 8 is the curve of symmetrical waveform of the generated wave, T.sub.F=T/2.

[0043] FIG. 9 is the curve of asymmetrical waveform of the generated wave, T.sub.F=T/2.

[0044] FIG. 10 is the curve of asymmetrical waveform of the generated wave, T.sub.F<T/2.

[0045] FIG. 11 is the curve of asymmetrical waveform of the generated wave, T.sub.F>T/2.

[0046] FIG. 12 is the curve of symmetrical waveform of the generated wave with a pulse delay, T.sub.F=T/2.

[0047] FIG. 13 is the curve of asymmetrical waveform of the generated wave with a pulse delay, T.sub.F<T/2.

DETAILED DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENT

[0048] While the present invention is susceptible of embodiment in various forms, there is shown in the drawings a number of presently preferred embodiments that are discussed in greater detail hereafter. It should be understood that the present disclosure is to be considered as an exemplification of the present invention, and is not intended to limit the invention to the specific embodiments illustrated. It should be further understood that the title of this section of this application (Detailed Description of the Illustrative Embodiment) relates to a requirement of the United States Patent Office, and should not be found to limit the subject matter disclosed herein.

[0049] Referring now to the drawings, where a preferred method of profiling surfaces of cross-sections of openings in the walls of elements of a mechanical system, shown as item 5 in FIG. 2, for generating pressure waves in elastic fluids is realized. As one of the possible variants of equidistantly located walls, let us consider the concentrically arranged cylindrical walls of the mechanical system for generating the pressure waves, formed from an outer housing 10 and an inner housing 15, shown in FIG. 1. A controlled drive 20 rotates a shaft 25. An outer housing 10 is fixed from rotation motion and forms a body 22, shown as item 95 on FIG. 2, of the mechanical system in a form of a second cylindrical wall 30 having an opening 35 enclosed by the polar angle alpha, . The second cylindrical wall 30, having inner 30a and outer 30b surfaces, is rigidly connected longitudinally to the end caps 40 held in a generally parallel configuration to each other. A collector 45 covers the surface of the profile of cross-section of opening 35 externally. The collector 45 is connected with a pipe (item 105 in FIG. 2). A volume V.sub.2 limited by the cylindrical fixed wall 30, the end caps 40, the collector 45 and the pipe 105, is formed in an inner chamber which is filled with elastic fluid exposed to over pressure, P.sup.+ (for example, connected to a discharge pipe 90 of a pump 80, shown on FIG. 2). An inner housing 15, placed into the outer housing, formed from a first cylindrical movable wall 50, having inner 50a and outer 50b surface, and an opening 52 with a surface of profile of a cross-section 55 (partially shown in FIG. 1; the entire surface of profile of the cross-section 55 is shown in FIG. 5). The first cylindrical movable wall 50 is rigidly connected longitudinally to the end caps, 70, 70a (FIG. 3), held in a generally parallel configuration to each other. The end caps 70, 70a are rigidly connected to shaft 25 (FIG. 1). End cap 70a, located on the opposite side of the control drive 20, will be seen to have an output connected to a pipe 60. An axis of symmetry 72 of the second cylindrical wall 30, of the end caps 40, of the first cylindrical movable wall 50 and of the end caps 70 coincides with the axis 27 of rotation of shaft 25 of the control drive 20.

[0050] It will be seen, in FIG. 1, that an inner symmetrical surface 30a of the second cylindrical wall 30 is equidistantly located relatively to an outer symmetrical surface 50b of the first movable cylindrical wall 50. A volume Y, limited by the cylindrical movable wall 50, the end caps 70, 70a, and the pipe 60 form a first volume filled with elastic fluid exposed to under pressure, P.sup. (for example, connected to a suction pipe of a pump 80 as shown in FIG. 2). The surfaces of cross-sections of profiles of openings 35 (FIG. 4) and 55 (FIG. 5) are located single-positionally in the walls 30 and 50 so that, when the wall 50 rotates, the surfaces of cross-sections of said profiles of openings 35 and 55 are intersecting and form a common surface S.sub.21 (FIG. 6).

[0051] In the operation of the mechanical system, at the initial moment of time, t=0, the value of the common surface S.sub.21=0; the first cylindrical movable wall 50 completely overlaps the surface of cross-section of the opening 35 (as shown in the closed dashed line on the right side on the FIG. 6). In this position, the first cylindrical movable wall 50 separates the volume of elastic fluid exposed to under pressure P.sup., applied to its inner surface from the volume of elastic fluid exposed to over pressure P.sup.+, applied to its outer surface, FIG. 1. Consequently, the connection of the volumes with pressures P.sup. and P.sup.+ is carried out only through the common surface S.sub.21, when its value is greater than zero, S.sub.21>0. End caps 40 close the mechanical system for generating pressure waves. Through the connecting pipe 60, the inner cavity 65 of the inner chamber communicates through elastic fluid exposed to under pressure, P.sup.. The inner surface 30a of the fixed wall 30 and the outer surface 50b of the movable wall 50 are separated by a thin gap 75, as shown in FIG. 3. The end caps 70, 70a, rigidly connected to the shaft 25, enclose the inner cavity 65.

[0052] FIG. 4 is a mapping of a part of the cylindrical surface of the outer cylindrical wall 30, on a plane surface, comprising the single-position location of the surface of profile of cross-section of the opening 35.

[0053] FIG. 5 shows a mapping of the whole surface of a first cylindrical movable wall 50 on a plane surface, comprising the single-positional profile 55 of the surface of cross-section of opening, enclosed by the polar angle beta, ; V is the direction of movement of the first cylindrical movable wall 50, V=*R is the linear velocity, Q is an angular velocity the movable wall 50, R is its radius.

Consider, for example, a mechanical system comprising a pressure wave generator 95, connected parallel to a pump 80, which is pumping elastic liquid with a flow rate G, as shown in FIG. 2. The pressures on the pump in the intake pipeline 85 and discharge pipeline 90 are equal to P.sup. and P.sup.+, respectively. The same pressures are applied in the connecting pipe 100 with the suction pipeline and in the collector 105 with a discharge pipeline, FIG. 2 (a connecting pipe 105 of the collector with a discharge pipeline 90 in FIG. 1 is not drawn.).

[0054] The method of invention is performed in the following manner. Suppose, for the purposes of simplicity, that at the initial instant of time t.sub.0=0, value of the common surface S.sub.21=0 (as represented by the closed dashed line on the right side on the FIG. 6). Consequently, the first cylindrical movable wall 50 completely overlaps the surface of cross-section of the opening 35 of the fixed wall 30. Mappings of the first cylindrical movable wall and of the second cylindrical wall on the plane is presented in FIG. 6. Besides mapping of the second cylindrical wall is located under the first movable wall, therefore, a contour line of the opening 35 is drawn as a dashed line. By turning on the drive 20, the shaft 25 rotates the movable wall 50 relatively to the fixed wall 30 around the axis of rotation 27. The process of intersection of surfaces of cross-sections of the profiles of openings 35 and 55 thereby begins. By this rotation, the value of the common surface becomes more than zero, as described here: S.sub.21>0 for t>0, see FIG. 6.

[0055] The process of exchange of pressure impulse between the volume with under pressure P.sup. and the volume with over pressure, P.sup.+ through the common surface S.sub.21 here begins. This process is accompanied by the generation of pressure waves on a common surface. At that, simultaneously, a rarefaction pressure wave and a compression pressure wave are generated. The rarefaction pressure wave is propagated through the elastic fluid of the inner chamber of the first housing; the compression pressure wave is propagated through the elastic fluid of the first volume, see FIG. 2. Parameters of the generated pressure waveswaveform, are defined unequivocally by the sizes of cylindrical walls 30 and 50, angular velocity of the first cylindrical movable wall 50 relatively to the fixed cylindrical wall 30, speed of change of the common surface vs. time, values of over pressure P.sup.+ and of under pressure P.sup., and physical properties of elastic fluid (density, viscosity, compressibility). This angular velocity, shapes, sizes, and single-position location of surfaces profiles of the cross-sections of openings 35 and 55 in the cylindrical walls 30 and 50 respectively of the first and of the second housing are already defined.

[0056] During the rotating motion of the cylindrical wall 50 relative to wall 30, the intersection of the surfaces of profiles of the cross-sections of openings 35 and 55 proceeds. The common surface S.sub.21 varies periodically: it increases from zero to the maximum value and decreases from the maximum value to zero. Besides, the increase of the common surface S.sub.21 to the maximum value during the time interval 0 . . . T.sub.F (T.sub.F being a front time of the waveform) there is carried out, by one law, and the decrease of the surface area from maximal value to zero, during the time interval T.sub.B=TT.sub.F (T.sub.B is the back time of the waveform) can be carried out by other law; T is a period of generated pressure waves. The laws of change of pressure (waveform) on the time intervals 0 . . . T.sub.F and T.sub.F . . . T are defined by solving of the technological problem of maximal efficiency interaction of pressure waves with the fluid. For example, the interaction of pressure waves with a turbulence of a fluid flow in a discharge pipeline. Solution of this problem depends on the physical properties of fluid, sizes and configuration of a pipeline.

[0057] The mapping of this motion is shown in FIG. 6. During the time interval 0 . . . T.sub.F, the movable cylindrical wall 50 rotates at the angle of ; simultaneously, pressures in the generated waves increase from zero to the amplitude values: p.sup.+ and p.sup., see FIG. 8. During the time interval T.sub.F the common surface S.sub.21 decreases from the maximum value to zero, see FIG. 6, while the movable cylindrical wall 50 rotates on the angle .

[0058] The pressure in the waves is restored: in the compression wave, from p.sup.+ to P.sup., and in the rarefaction wave, from p.sup. to P.sup.+. Wherein, the period of variation of the common surface S.sub.21 is equal to the period of the generated waves, T. The compression pressure wave p.sup.+ is formed only as a result of the exchange of the pressure impulse on the common surface S.sub.21 during the change of said surface from zero to the maximum value and from the maximal value to zero. On the time interval 0 . . . T.sub.F the rarefaction pressure wave is forming as a result of the change on pressure impulse between the volumes with different pressures, P.sup. and P.sup.+ while the common surface S.sub.21 is increasing. The recovery of pressure in rarefaction wave on the time interval T.sub.F . . . T is due not only to decrease of the change of pressure impulse by the decrease of the common surface S.sub.21 from a maximum value to zero, but also partially due to the reflection of the pressure impulse from the outer surface of the movable wall 55.

[0059] Analysis of the Shapes of the Laws of Change of the Pressure in Generated Waves.

[0060] In FIGS. 6 and 7, it will be seen that the mapping of the entire cylindrical surface of the fixed wall 30 and movable wall 50's cylindrical walls on the plane surface comprising the surfaces of cross-sections of profiles of the openings 35 and 55, respectively, are presented. The profile of the opening 55 on the cylindrical surface enclosed by the polar angle beta, . The angle gamma, , encloses a part of cylindrical movable wall 50 not comprising any part of the profile of the opening 55. The ratio between the angles and is controlling the value of the delay of repetition of the pressure pulses in the generated wave.

[0061] At +=2, two cases are possible. =, see FIG. 7 and >, see FIG. 6. At retaining the shape, dimensions and the same location of the cross-sections of the profile of the surface of openings and the conditions = and > are provided on cylindrical elements of different radii. When gamma is equal to delta, FIG. 7, the following laws of pressure change in a generating waves are possible: symmetrical law, for example, sinusoidal, parabolic, see FIG. 8, and asymmetrical, to the right or to the left, see FIG. 10 and FIG. 11, respectively.

[0062] Let us consider the case of =. In this case the symmetrical, FIG. 7 and asymmetrical, FIG. 9 waveform of the generated waves is provided. These waveforms are obtained for T.sub.F=T/2. The essence of generating pressure waves by the given waveform is the following: it is necessary to provide such sizes, shapes, dimensions and single-position location of the surfaces of cross-sections of profiles of the openings 35 and 55 in the fixed and movable walls 30, 50 of the cylindrical elements of the mechanical system which, when these surfaces are intersecting during the relative motion of said elements, such law of change of the common surface S.sub.21 of the volumes with different pressures P.sup. and P.sup.+ is realized, which provides the generating of the pressure waves by the given waveform/law. Parameters of generated pressure waves relate to physical properties of fluid: density viscosity, compressibility.

[0063] If the cross-section area S.sub.12 increases from zero to the maximum value at the time interval T.sub.F=T/2, then the pressure waves are generated according to a symmetric waveform/law. If the cross-section area S.sub.21 increases to the maximum value and decreases to zero by a symmetric law, for example: on parabola, then the law of pressure change in the generated wave is also symmetrical, see FIG. 8. If these laws are different then the waveform of pressure change of the generated waves are also different, see FIG. 9 and FIG. 10.

[0064] Let's assume that for improve the energy efficiency of a technological process is necessary to generate a pressure wave with the determined specified asymmetric waveform/law of change of pressure vs. time, for example, T.sub.F<T/2, by =. Then is necessary to provide such sizes of cylindrical walls, shapes, sizes and the single-position location of profile of the surfaces of cross-sections of openings 35 and 55 in the fixed and movable walls 30, 50 of these housings that would increase the value cross-section area S.sub.21 from the maximum value by one law and a decrease of S.sub.21 from the maximal value to zero by another law. The law of change of surface of cross-section S.sub.21 vs. time should provide the generation pressure waves of the required parameters. By changing the shape, sizes and location of profile of surfaces of cross-section of opening 55 could be readily obtained the law of change of the cross-section area S.sub.21 which generates a pressure wave by the law shown in FIG. 11.

[0065] If the >, see FIG. 5, then the impulses in the generated pressure wave follow with a certain delay, see FIGS. 12 and 13. The value of the pressure pulse delay is determined by the technological problems. Physically, this is provided by increasing of the surface of cross-section of opening 55, of the movable wall 50, see FIG. 5; that is, by another choice of shape, sizes and location of the single-position profile of the surface of cross-section of opening 55.

[0066] For the same shape and sizes of the profiles as well as the single-position location of profiles of the surfaces of cross-sections of the opening 35 and 55, for the same speed of rotation of the movable wall 50 the amplitude of generated pressure waves is inversely proportional to the compressibility of the elastic fluid.

[0067] From this physical condition follows the limitation of the lower sizes on the geometric dimensions of the elements of the mechanical system for generating pressures waves, mentioned above. Hence, the comparative evaluation of the shape and sizes of profiles of the cross-sections of the openings 35 and 55 depends on the elastic properties of the fluid. The elastic properties of the fluid are given in initial conditions of the problem as a technological parameter.

[0068] To improve the energy efficiency of a technological process, for example, transporting of a medium flow through a discharge pipeline, is necessary to change the interaction between full specific energy of the flow and the specific wave energy of generated pressure waves (symmetrical or asymmetrical) and their propagating through the flow. This is provided by changing of a value of frequency of generating pressure waves with simultaneously changing of the front time, back time and amplitude (whole waveform). These lead to change and to adjusting such the structure of the flow, which provides a maximal value of energy efficiency of pipeline transporting process, which is confirmed by minimal value of the pressure difference (P.sup.+P.sup.) measured on the pump.

[0069] Based on this:

[0070] The waveform/law of the pressure change in the generated waves is determined by the pressure difference (P.sup.+P.sup.) measured on the pump, sizes of cylindrical walls, by the shape and sizes of surfaces of profiles of cross-sections of openings and their single-position location in the first and second walls and is carried out so, that provides the requested law of change of the common surface S.sub.21 which provides the generation of the pressure waves by predetermined law.