Fluidic propulsive system

Abstract

A propulsion system coupled to a vehicle. The system includes a convex surface, a diffusing structure coupled to the convex surface, and at least one conduit coupled to the convex surface. The conduit is configured to introduce to the convex surface a primary fluid produced by the vehicle. The system further includes an intake structure coupled to the convex surface and configured to introduce to the diffusing structure a secondary fluid accessible to the vehicle. The diffusing structure comprises a terminal end configured to provide egress from the system for the introduced primary fluid and secondary fluid.

Claims

1. A propulsion system coupled to a vehicle, the system comprising: a convex surface having a perimeter and a plurality of recesses; a diffusing structure coupled to the convex surface; at least one conduit coupled to the convex surface and configured to introduce to the convex surface via multiple nozzles distributed along the entirety of the perimeter a primary fluid produced by the vehicle; and an intake structure coupled to the convex surface and configured to introduce to the diffusing structure a secondary fluid accessible to the vehicle, wherein the nozzles are downstream of the intake structure, and wherein the diffusing structure comprises a terminal end configured to provide egress from the system for the introduced primary fluid and secondary fluid.

2. The system of claim 1, wherein the at least one conduit comprises an array of nozzles arranged in at least one of a curved orientation, a spiraled orientation, and a zigzagged orientation.

3. The system of claim 1, wherein the intake structure is asymmetrical.

4. A propulsion system coupled to a vehicle, the system comprising: a diffusing structure; at least one conduit coupled to the diffusing structure and configured to introduce to the diffusing structure a primary fluid produced by the vehicle; and an asymmetrical intake structure coupled to the diffusing structure and configured to introduce to the diffusing structure a secondary fluid accessible to the vehicle, wherein the diffusing structure comprises a terminal end configured to provide egress from the system for the introduced primary fluid and secondary fluid, and wherein the intake structure comprises first and second lateral opposing edges, and the first lateral opposing edge has a greater radius of curvature than the second lateral opposing edge.

5. The system of claim 4, wherein the at least one conduit comprises an array of conduits arranged in at least one of a curved orientation, a spiraled orientation, and a zigzagged orientation.

6. The system of claim 4, further comprising a convex surface, wherein the at least one conduit is configured to introduce to the convex surface the primary fluid produced by the vehicle.

7. A propulsion system coupled to a vehicle, the system comprising: a diffusing structure; at least one conduit coupled to the diffusing structure and configured to introduce to the diffusing structure a primary fluid produced by the vehicle; and an asymmetrical intake structure coupled to the diffusing structure and configured to introduce to the diffusing structure a secondary fluid accessible to the vehicle, wherein the diffusing structure comprises a terminal end configured to provide egress from the system for the introduced primary fluid and secondary fluid, and wherein the intake structure comprises first and second opposing edges, and the second opposing edge includes a curved portion projecting toward the first opposing edge.

8. The system of claim 7, wherein the at least one conduit comprises an array of conduits arranged in at least one of a curved orientation, a spiraled orientation, and a zigzagged orientation.

9. The system of claim 7, further comprising a convex surface, wherein the at least one conduit is configured to introduce to the convex surface the primary fluid produced by the vehicle.

Description

BRIEF DESCRIPTION OF THE DRAWING FIGURES

(1) FIG. 1 is a cross-section of one embodiment of the present invention depicting the upper half of an ejector and profiles of velocity and temperature within the internal flow;

(2) FIG. 2 illustrates features of surfaces of the ejector of FIG. 1 according to an embodiment;

(3) FIGS. 3-4 illustrate partial perspective views of intake structures according to one or more embodiments;

(4) FIG. 5 is a rear plan view of an actuator according to an embodiment;

(5) FIG. 6 illustrates in cross-section alteration of ejector internal geometries according to an embodiment;

(6) FIG. 7 is a side perspective view of an alternative embodiment;

(7) FIG. 8 is a side view of element of the embodiment illustrated in FIG. 7; and

(8) FIGS. 9-11 illustrate another alternative embodiment of the invention.

DETAILED DESCRIPTION

(9) This application is intended to describe one or more embodiments of the present invention. It is to be understood that the use of absolute terms, such as must, will, and the like, as well as specific quantities, is to be construed as being applicable to one or more of such embodiments, but not necessarily to all such embodiments. As such, embodiments of the invention may omit, or include a modification of, one or more features or functionalities described in the context of such absolute terms. In addition, the headings in this application are for reference purposes only and shall not in any way affect the meaning or interpretation of the present invention.

(10) One embodiment of the present invention includes a propulsor that utilizes fluidics for the entrainment and acceleration of ambient air and delivers a high speed jet efflux of a mixture of the high pressure gas (supplied to the propulsor from a gas generator) and entrained ambient air. In essence, this objective is achieved by discharging the gas adjacent to a convex surface. The convex surface is a so-called Coanda surface benefitting from the Coanda effect described in U.S. Pat. No. 2,052,869 issued to Henri Coanda on Sep. 1, 1936. In principle, the Coanda effect is the tendency of a jet-emitted gas or liquid to travel close to a wall contour even if the direction of curvature of the wall is away from the axis of the jet. The convex Coanda surfaces discussed herein with respect to one or more embodiments does not have to consist of any particular material.

(11) FIG. 1 illustrates a cross-section of the upper half of an ejector 200 that may be attached to a vehicle (not shown), such as, for non-limiting examples, a UAV or a manned arial vehicle, such as an airplane. A plenum 211 is supplied with hotter-than-ambient air (i.e., a pressurized motive gas stream) from, for example, a combustion-based engine that may be employed by the vehicle. This pressurized motive gas stream, denoted by arrow 600, is introduced via at least one conduit, such as primary nozzles 203, to the interior of the ejector 200. More specifically, the primary nozzles 203 are configured to accelerate the motive fluid stream 600 to a variable predetermined desired velocity directly over a convex Coanda surface 204 as a wall jet. Additionally, primary nozzles 203 provide adjustable volumes of fluid stream 600. This wall jet, in turn, serves to entrain through an intake structure 206 secondary fluid, such as ambient air denoted by arrow 1, that may be at rest or approaching the ejector 200 at non-zero speed from the direction indicated by arrow 1. In various embodiments, the nozzles 203 may be arranged in an array and in a curved orientation, a spiraled orientation, and/or a zigzagged orientation.

(12) The mix of the stream 600 and the air 1 may be moving purely axially at a throat section 225 of the ejector 200. Through diffusion in a diffusing structure, such as diffuser 210, the mixing and smoothing out process continues so the profiles of temperature (800) and velocity (700) in the axial direction of ejector 200 no longer have the high and low values present at the throat section 225, but become more uniform at the terminal end 100 of diffuser 210. As the mixture of the stream 600 and the air 1 approaches the exit plane of terminal end 100, the temperature and velocity profiles are almost uniform. In particular, the temperature of the mixture is low enough to be directed towards an airfoil such as a wing or control surface.

(13) In an embodiment, and as best illustrated in FIG. 2, V-shaped, vortex generating secondary nozzles 205 are staggered when compared to a normal rectangular primary nozzle 203 and injecting at least 25% of the total fluid stream 600 before the balance of the fluid stream massflow is injected at a moment later by nozzles 203. This injection by nozzles 205 prior to that of nozzles 203 results in a higher entrainment rate enough to significantly increase the performance of the ejector 200. Secondary nozzles 205 introduce a more-favorable entrainment of the secondary flow via shear layers and are staggered both axially and circumferentially in relation to the primary nozzles 203.

(14) Primary nozzles 203 may include a delta-wing structure 226 that is provided with a supporting leg connected to the middle point of the primary nozzle 203 structure at its innermost side, with a delta-wing structure apex pointing against the fluid stream 600 flow. This in turn generates two vortices opposed in direction and strongly entraining from both sides of primary nozzle 203 the already entrained mixture of primary and secondary fluid flows resulting from nozzles 205.

(15) Additionally, an embodiment improves the surface for flow separation delay via elements such as dimples 221 placed on the Coanda surface 204. The dimples 221 prevent separation of the flow and enhance the performance of the ejector 200 significantly. Additionally, surfaces of the diffuser 210 (see FIG. 1) may also include dimples 222 and/or other elements that delay or prevent separation of the boundary layer.

(16) In an embodiment, intake structure 206 may be circular in configuration. However, in varying embodiments, and as best shown in FIGS. 3-4, intake structure 206 can be non-circular and, indeed, asymmetrical (i.e., not identical on both sides of at least one, or alternatively any-given, plane bisecting the intake structure). For example, as shown in FIG. 3, the intake structure 206 can include first and second opposing edges 301, 302, wherein the second opposing edge includes a curved portion projecting toward the first opposing edge. As shown in FIG. 4, the intake structure 206 can include first and second lateral opposing edges 401, 402, wherein the first lateral opposing edge has a greater radius of curvature than the second lateral opposing edge.

(17) Referring to FIG. 5, an embodiment may include at least one actuating element 501 coupling the ejector 200 to a vehicle 502. Element 501 is configured to provide at least two, and preferably three, dimensions of movement (i.e., six degrees of freedom) of the ejector 200 relative to the vehicle 502.

(18) Referring to FIG. 6, an embodiment may include at least one internal actuating element (e.g., actuators and/or linkages) 601, 602 disposed between external surfaces 603, 604 and internal surfaces 605, 606 of ejector 200. In the illustrated embodiment, actuator 601 is configured to move (e.g., toward and away from the center axis of ejector 200) the first surface 605 relative to the second surface 606 when the second surface is not moving. Similarly, second actuator 602 is configured to move the second surface 606 relative to the first surface 605 when the first surface is not moving. This ability to alter the internal geometry of the ejector 200 into multiple configurations allows ejector to optimally operate in multiple flight conditions (e.g., liftoff, takeoff, cruising flight, etc.).

(19) FIG. 7 illustrates a propulsion system for a vehicle 700 according to an alternative embodiment. A first secondary airfoil 702 is coupled to the vehicle 700 and positioned downstream of fluid flowing over a primary airfoil 701 of the vehicle. Airfoil 702 is configured to rotate about axis 707 and controlled by an actuator 708. As best illustrated in FIG. 8, the first secondary airfoil 702 includes a first output structure, such as opposing nozzle surfaces 705, 706 and at least one conduit, such as plenum 704, in fluid communication with a terminal end 703 defined by the nozzle surfaces. Nozzle surfaces 705, 706 may or may not include nozzles similar to nozzles 203 discussed above with reference to FIG. 1. Additionally, one or more of nozzle surfaces 705, 706 may include a convex surface that can, consequently, promote the Coanda effect and may have continuously rounded surfaces with no sharp or abrupt corners. Plenum 704 is supplied with hotter-than-ambient air (i.e., a pressurized motive gas stream) from, for example, a combustion-based engine that may be employed by the vehicle 700. Plenum 704 is configured to introduce this gas stream to the terminal end 703, which is configured to provide egress for the gas stream toward the primary airfoil 701 and out of the first secondary airfoil 702.

(20) Referring to FIGS. 9-11, an embodiment may include a second secondary airfoil 902 similar to airfoil 702, each with a respective trailing edge 714, 914 diverging from the other trailing edge. More particularly, second secondary airfoil 902 is coupled to the vehicle 700 and positioned downstream of fluid flowing over the primary airfoil 701 of the vehicle. Airfoil 902 is configured to rotate in a manner similar to that discussed above with reference to airfoil 702. Airfoil 902 includes a first output structure, such as opposing nozzle surfaces 905, 906 and at least one conduit, such as plenum 904, in fluid communication with a terminal end 903 defined by the nozzle surfaces. Nozzle surfaces 905, 906 may or may not include nozzles similar to nozzles 203 discussed above with reference to FIG. 1. Additionally, one or more of nozzle surfaces 905, 906 may include a convex surface that can, consequently, promote the Coanda effect. Plenum 904 is supplied with hotter-than-ambient air (i.e., a pressurized motive gas stream) from, for example, a combustion-based engine that may be employed by the vehicle 700. Plenum 904 is configured to introduce this gas stream to the terminal end 903, which is configured to provide egress for the gas stream toward the primary airfoil 701 and out of the second secondary airfoil 902.

(21) Each of the first and second secondary airfoils 702, 902 has a leading edge 716, 916 disposed toward the primary airfoil, with the first secondary airfoil opposing the second secondary airfoil. In operation, the first and second secondary airfoils 702, 902 define a diffusing region 802, therebetween and along their lengths, similar in function to diffuser 210 discussed above herein. The leading edges 716, 916 define an intake region 804 configured to receive and introduce to the diffusing region 802 the gas streams from plena 704, 904 and the fluid flowing over the primary airfoil 701. The diffusing region 802 includes a primary terminal end 806 configured to provide egress from the diffusing region for the introduced gas streams and fluid flowing over the primary airfoil 701.

(22) Although the foregoing text sets forth a detailed description of numerous different embodiments, it should be understood that the scope of protection is defined by the words of the claims to follow. The detailed description is to be construed as exemplary only and does not describe every possible embodiment because describing every possible embodiment would be impractical, if not impossible. Numerous alternative embodiments could be implemented, using either current technology or technology developed after the filing date of this patent, which would still fall within the scope of the claims.

(23) Thus, many modifications and variations may be made in the techniques and structures described and illustrated herein without departing from the spirit and scope of the present claims. Accordingly, it should be understood that the methods and apparatus described herein are illustrative only and are not limiting upon the scope of the claims.