fluid accelerator

Abstract

We provide a fluid accelerator used to utilize energy from a flowing fluid. [Solution] The fluid accelerator (1100) has an inlet end (1110) and an outlet end (1115), and includes an outer housing (1105) that defines a converging nozzle near the inlet end (1110), and includes an annular ring (1130) located near the inlet end (1110) of the outer housing within the converging nozzle.

Description

Technical Field

[0001] The present invention generally relates to a fluid accelerator, and more particularly to a fluid accelerator including an airfoil circular ring, a convergent nozzle, and a bidirectional turbine wheel.

Background Art

[0002] Various fluid systems are used to utilize the energy from the flowing fluid. For example, wind turbines and ram air turbines convert the energy from the air flow into electric power and / or hydraulic power. Further, other fluid systems generate thrust by adding energy to the fluid flow to accelerate the fluid flow. For example, a jet engine burns fuel to accelerate the intake air and generate thrust. The efficiency and effectiveness of both types of systems are limited by the velocity of the fluid flow on the inlet side of the fluid system. It is considered beneficial to accelerate the fluid flow on the inlet side of both types of systems. However, most fluid acceleration devices require power to introduce energy into the fluid flow. In a system aimed at extracting energy from a fluid system, if power is required to accelerate the fluid flow before the inlet of the fluid system, the efficiency will be significantly reduced. Similarly, in a system that already uses power to accelerate the fluid flow, adding another device that also requires power is generally not an efficient approach.

[0003] In the art, there is a need for systems and methods to address the above drawbacks.

Summary of the Invention

Problems to be Solved by the Invention

[0004] The present disclosure relates to a passive fluid accelerator. This passive fluid accelerator significantly improves the efficiency and effectiveness of energy generation systems such as ram air turbines and significantly improves the output and efficiency of energy consumption systems such as jet engines. [Means for solving the problem]

[0005] One aspect of the present disclosure relates to a fluid accelerator. The fluid accelerator is an outer housing having an inlet end and an outlet end, which may include an outer housing defining a converging nozzle near the inlet end. The fluid accelerator may also include an annular ring disposed within the converging nozzle near the inlet end of the outer housing, which has an airfoil cross-sectional shape.

[0006] In another embodiment, the disclosure relates to a fluid accelerator. The fluid accelerator may include an outer housing having an inlet end and an outlet end, the outer housing defining a nozzle near the inlet end, and an annular ring disposed within the nozzle near the inlet end of the outer housing. The annular ring may have an airfoil cross-sectional shape.

[0007] Furthermore, the annular ring may have a leading edge, a trailing edge, a suction side, and a pressure side. The airfoil cross-sectional shape may include a base portion having a first surface associated with the pressure side and a second surface associated with the suction side, an overhang portion (182) extending over a portion of the base, and an elliptical portion connecting the base and the overhang portion adjacent to the leading edge. The overhang portion may be curved toward the second surface of the base.

[0008] In another embodiment, the disclosure relates to a fluid accelerator. The fluid accelerator may include an outer housing having an inlet end and an outlet end, the outer housing defining a nozzle near the inlet end, and an annular ring disposed within the nozzle near the inlet end of the outer housing. The annular ring may have an airfoil shape, and may have an airfoil suction side and an airfoil pressure side. The annular ring may be angled such that the airfoil suction side is inclined downstream toward the outlet end, and the airfoil pressure side is inclined upstream toward the inlet end.

[0009] In another embodiment, the disclosure relates to a turbine wheel. The turbine wheel may include an inner hub having a central axis, an outer ring concentric with the inner hub, and an intermediate ring concentrically positioned between the inner hub and the outer ring. The turbine wheel may also include a plurality of turbine blades (1515) extending between the intermediate ring and the outer ring, the turbine blades being oriented to be driven by a fluid flow through the turbine wheel to rotate the turbine wheel in a first direction about the central axis. Furthermore, the turbine wheel may include a plurality of compressor blades extending between the inner hub and the intermediate ring, the compressor blades being oriented to propel the fluid downstream when the turbine wheel is rotated in the first direction.

[0010] In another embodiment, the disclosure relates to a turbine wheel (1150). The turbine wheel may include a plurality of turbine blades oriented to rotate the turbine wheel in a first direction about a central axis, driven by a fluid flow through the turbine wheel. The turbine wheel may also have a plurality of compressor blades oriented to propel the fluid downstream as the turbine wheel rotates in the first direction. The turbine blades and / or compressor blades may have an airfoil shape. The airfoil shape may include a base portion including a first surface associated with the pressure side and a second surface associated with the suction side, an overhang portion extending over a portion of the base, and an elliptical portion connecting the base and the overhang portion adjacent to the leading edge. The overhang portion may curve toward the second surface of the base.

[0011] In another embodiment, the disclosure relates to a fluid accelerator. The fluid accelerator is an outer housing having an inlet end and an outlet end, and may include an outer housing defining a nozzle near the inlet end. Furthermore, the fluid accelerator may include an annular ring (1130) located near the inlet end of the outer housing within the nozzle, the annular ring having an airfoil cross-sectional shape. The fluid accelerator may also include a turbine wheel located in the outer housing downstream of the annular ring. The turbine wheel may include an inner hub having a central axis, an outer ring concentric with the inner hub, and an intermediate ring concentrically located between the inner hub and the outer ring. The turbine wheel may also include a plurality of turbine blades extending between the intermediate ring and the outer ring, the turbine blades being oriented to rotate the turbine wheel in a first direction about its central axis, driven by a fluid flow through the turbine wheel. Furthermore, the turbine wheel may include a plurality of compressor blades extending between the inner hub and the intermediate ring, the compressor blades being oriented to drive the fluid downstream when the turbine wheel is rotated in the first direction.

[0012] Other systems, methods, features, and advantages of the present invention will be apparent or will become apparent to those skilled in the art upon consideration of the following drawings and detailed description. All such further systems, methods, features, and advantages are contained herein and in this abstract, are within the scope of the present invention, and are protected by the following claims.

[0013] The present invention can be better understood by referring to the following drawings and description. The components in the drawings are not necessarily to scale, and instead the focus is on illustrating the principles of the present invention. Furthermore, in the drawings, the same reference numbers indicate the corresponding parts in different drawings. [Brief explanation of the drawing]

[0014] [Figure 1] This is a schematic isometric view showing an embodiment of a wing along the pressure side. [Figure 2] This is a schematic isometric view showing the suction side of the wing in Figure 1. [Figure 3] This is a schematic side view showing one embodiment of the wing. [Figure 4] Figure 3 is a schematic side view of the wing, showing the curvature of various parts of the wing. [Figure 5] This is a schematic diagram of one embodiment of a wing showing the passage lines of airflow elements. [Figure 6] This is a schematic diagram showing an aircraft, including a magnified view of the externally exposed components of a ram air turbine system. [Figure 7] This is a schematic diagram showing the components of a ram air turbine system within an aircraft body shell. [Figure 8] This is a schematic rear view showing a ram air turbine according to an exemplary embodiment. [Figure 9] This schematic diagram shows an aircraft including an enlarged view of externally exposed components of a ram air turbine system according to another embodiment. [Figure 10] This schematic diagram shows an aircraft including an enlarged view of externally exposed components of a ram air turbine system according to another alternative embodiment. [Figure 11] This is a schematic diagram of a front perspective view of a fluid accelerator according to an exemplary embodiment. [Figure 12] Figure 11 is a schematic diagram showing a rear perspective view of a fluid accelerator. [Figure 13] Figure 11 is a schematic diagram showing a rear perspective exploded view of a fluid accelerator. [Figure 14] Figure 11 is a schematic diagram showing a perspective view of the cutaway cross-section of the nozzle of a fluid accelerator. [Figure 15] Figure 11 is a schematic diagram showing a cross-sectional perspective view of the nozzle and turbine wheel of a fluid accelerator. [Figure 16] Figure 11 is a schematic diagram showing a notched cross-sectional perspective view of a fluid accelerator. [Figure 17]FIG. 11 is a schematic view showing a cutaway cross-sectional perspective view of the outer housing and the annular ring of the fluid accelerator, and shows the fluid flow pattern affected by the outer housing and the annular ring. [Figure 18] FIG. 11 is a schematic view showing a cutaway cross-sectional view of the turbine wheel of the fluid accelerator. [Figure 19] FIG. 6 is a schematic view showing an airplane with a fluid accelerator attached to the inlet of a turbine engine.

DETAILED DESCRIPTION OF THE INVENTION

[0015] The present disclosure relates to a system for implementing a wing having a hook-shaped cross-sectional shape. The wings of the disclosed embodiments may implement one or more wings described in U.S. Patent No. 10,766,544 by Suk et al., issued September 8, 2020, titled "Airfoils and Machines Incorporating Airfoils" (the entire disclosure of which is incorporated herein by reference).

[0016] Furthermore, the present disclosure relates to a system that can be used in a ram air turbine system mounted internally. Accordingly, the disclosed system may be used in a ram air turbine system having one or more features described in U.S. Patent Application No. 18 / 173,748 by Suk et al., filed February 23, 2023, titled "Ram Air Turbine" (the entire disclosure of which is incorporated herein by reference).

[0017] As used herein, the term "wing" (or "airfoil") refers to any structure having a curved surface that generates aerodynamic force when moving through a fluid. As used herein, the term "fluid" may refer to any Newtonian fluid. In another embodiment, the wing can be used with non-Newtonian fluids.

[0018] The wing may include an upper or suction surface over which the fluid flows at a relatively high speed and low static pressure. The wing may also include a lower or pressure surface with a higher static pressure compared to the suction surface. Alternatively, the suction surface and pressure surface may be referred to as the suction side and the pressure side. The wing also includes a leading edge, defined as the leading end of the wing with the greatest curvature. The wing also includes a trailing edge, defined as the trailing end of the wing with the least curvature. Furthermore, the chord of the wing refers to the straight line between the leading edge and the trailing edge. The mean curvature line is the locus of the midpoint between the upper and lower surfaces, and may or may not coincide with the chord depending on the shape of the wing.

[0019] In this specification, a wing has a chord length, defined as the length of the wing's chord line. Furthermore, a wing has a thickness, defined as the distance between the upper and lower surfaces along a line perpendicular to the mean curvature line. The wing width is measured using directions perpendicular to both the chord line and the thickness.

[0020] Throughout this specification and the claims, the term “radius of curvature” is used. The radius of curvature is the reciprocal of the curvature at a particular point on a curve or a two-dimensional surface. With respect to a curve, the radius of curvature is equal to the radius of the arc that best approximates the curve at that point. In particular, it should be noted that the larger the radius of curvature of a curve, the smaller the curvature (and vice versa).

[0021] From here Figures 1 and 2 show schematic isometric views of the wing (or blade) 100, and Figure 3 shows a schematic side view of the wing 100. Referring to Figures 1 to 3, the wing 100 is composed of a pressure side 102 (shown in Figure 1) and an opposing suction side 104 (shown in Figure 2). These sides each include a surface that comes into contact with air during operation (e.g., the pressure side or the suction side). Furthermore, the wing 100 includes a leading edge 110 and a trailing edge 112. The leading edge 110 and the trailing edge 112 are connected by a chord wire 114 (see Figure 3).

[0022] Referring to Figure 3, in some embodiments of the invention, the blade 100 may consist of a body 101 made of a single material. In some embodiments, the blade 100 may consist of a single piece made of a single material. The body 101 includes a base 180 which is seen to gradually curve along the longitudinal direction of the blade 100, starting from the trailing edge 112. The base 180 includes a first surface 187 on the pressure side 102 of the blade 100 and an opposing second surface 188 on the opposing suction side 104.

[0023] At the end of the base 180, the main body 101 is curved to form a bent portion or hook-shaped portion adjacent to the front edge 110. That is, adjacent to the front edge 110, the main body 101 is composed of an elliptical portion 142 and an overhang portion 182 that hangs down or extends over a part of the base 180. The elliptical portion 142 connects the base 180 and the overhang portion 182 and also includes the front edge 110.

[0024] In some embodiments, the overhang portion 182 may be spaced apart from or separated from the base portion 180. In the embodiment shown in Figure 3, the overhang portion 182 is spaced apart from the base portion 180 by a gap 195. In various embodiments, the size of the gap 195 may vary. In some cases, the gap 195 may be greater than or equal to the thickness of the overhang portion 182. In some cases, the gap 195 may be at least three times the thickness of the overhang portion 182. The size of the gap 195, i.e., the distance between the base portion 180 and the overhang portion 182, determines the behavior of the airflow across the wing 100. Therefore, as will be described in more detail below, the gap 195 may be set to an appropriate size accordingly to provide the desired airflow behavior.

[0025] The fold in the main body 101 adjacent to the leading edge 110 may be considered to divide the wing 100 into two parts having a specific geometric shape, namely the front wing 120 and the rear wing 122. As shown in Figure 3, the front wing 120 is formed by the elliptical portion 142, the overhang portion 182, and the front segment of the base 180. The rear wing 122 is formed by the rear segment of the base 180.

[0026] In various embodiments, the length of the wing front section 120 relative to the total length of the wing (i.e., the percentage of the total length of the wing covered and extended by the overhang) can be varied. In some cases, the wing front section 120 has a relative length of 25 to 50 percent of the total length of the wing. In one embodiment, the wing front section 120 has a length of at least 25 percent of the total length of the wing. In yet another embodiment, the wing front section has a length of at least one-third of the total length of the wing. In some cases, the wing front section may be long enough (at least about 25 percent of the total length of the wing) to allow the first arc section to gradually curve downward toward the second arc section, thereby helping to keep the boundary layer attached to the wing before the thickness adjacent to the second arc section decreases dramatically.

[0027] As shown in Figure 3, the body 101 has a relatively constant local thickness 103 throughout the wing 100. However, the folded shape of the body 101 that forms the overhang portion 182 has a greater overall thickness at the fore-wing portion 120 than at the rear-wing portion 122. In this case, the overall thickness is measured between the opposing suction side 104 and pressure side 102 and differs from the local thickness of the body. Specifically, the fore-wing portion 120 has a variable thickness 130 with a maximum value adjacent to the leading edge 110 and a minimum value at the position furthest from the leading edge 110. In contrast, the rear-wing portion 122 has a nearly constant thickness. In some embodiments, the thickness of the rear-wing portion 122 is approximately equal to the local thickness 103 of the body 101. In other embodiments, the rear-wing portion 122 may also have a variable thickness.

[0028] The wing may include measures to maintain the “sticking” of the airflow at the intake surface so that the air can be redirected at a large angle (for example, from a nearly horizontal direction for incoming air to a nearly vertical direction for outgoing air). In some embodiments, the wing may include a wing front section that includes one or more arcs for controlling the airflow along the intake surface.

[0029] In some embodiments, the overhang portion 182 may further consist of a first arc portion 152 and a second arc portion 154. The first arc portion 152 may extend from the elliptical portion 142, and the second arc portion 154 may be located at the open end or free end of the overhang portion 182. In some embodiments, the curvature of the overhang portion 182 (along the opposing suction side 104) may vary from the first arc portion 152 to the second arc portion 154. In some cases, the first arc portion 152 may be configured to curve downward toward the base portion 180. Furthermore, the second arc portion 154 may be configured to have a steeper curvature, similarly curving downward toward the base portion 180.

[0030] In the following description, the radii of curvature of various surfaces are defined with respect to a unit radius length (denoted as "UN"). In various embodiments, the specific value of the unit radius length can be varied. For example, the unit radius value can be 100 mm (i.e., 1 UN = 100 mm), 6 inches (i.e., 1 UN = 6 inches), or any value. It will be understood that the ratio of two radii of curvature does not depend on the specific value of the unit radius. Thus, if the radius of curvature of the first surface is 1 UN and the radius of curvature of the second surface is 0.5 UN, the ratio is 1 divided by 0.5, i.e., 2, which is a dimensionless quantity that does not depend on the unit radius length in a particular embodiment.

[0031] Figure 4 shows a schematic side view of the wing 100. Referring to Figures 3 and 4, different parts or segments of the wing 100 may have different curvatures. In some embodiments, the wing rear section 122 has a rear arc section 160 immediately adjacent to the trailing edge 112. The rear arc section 160 has a radius of curvature 200. In some cases, as shown in Figure 4, the radius of curvature 200 may have a value of approximately 0.1000 UN. In some embodiments, the main segment 162 of the wing rear section 122 has a radius of curvature 202 along the pressure side 102 and a radius of curvature 204 along the opposing suction side 104. In some cases, the radius of curvature 202 may have a value of approximately 1.1250 UN. In some cases, the radius of curvature 204 may have a value of approximately 1.1750 UN. In some embodiments, the elliptical portion 142 has a radius of curvature 206 on the outward side 170 and a radius of curvature 208 on the inward side 172. In some cases, the radius of curvature 206 has a value of approximately 0.1500 UN. In some cases, the radius of curvature 208 has a value of approximately 0.1000 UN.

[0032] In some embodiments, the first arc portion 152 has a radius of curvature 210 along the opposing suction side 104 and a radius of curvature 212 along the inward surface 190. In some cases, the radius of curvature 210 has a value of approximately 0.7500 UN. In some cases, the radius of curvature 212 has a value of approximately 0.7000 UN. Furthermore, the second arc portion 154 has a radius of curvature 214. In some cases, the radius of curvature 214 has a value of approximately 0.1000 UN.

[0033] In some embodiments, the curvature of each segment of the wing 100 may be selected to help keep the boundary layer of flowing air attached to the opposing suction side 104, even when the wing 100 is curved from the leading edge 110 to the trailing edge 112.

[0034] Figure 5 is a schematic diagram of the wing 100 in operation as air passes through it. Referring to Figure 5, the incoming air flows in the first direction 300 and first encounters the leading edge 110. The air moving across the opposing intake side 104 first crosses the first arc 152, and this air curves into the second arc 154. The air is then guided to the rear of the wing 122. As the air flows along the rear of the wing 122, it is guided to the rear arc 160 and curves as it exits the trailing edge 112.

[0035] The geometric shape of the leading edge 120 of the wing forms a step 310, resulting in a sharp change in thickness between the leading edge 120 and the trailing edge 122. This sharp change in thickness (and geometric shape) creates vortices 320 (and / or turbulent vortices) at the step 310. As air flows over the opposing intake side 104, the vortices 320 "pull" the air toward the wing, thereby re-attaching the flow boundary layer as the flow moves from one section of the wing to the next, keeping the air "stuck" to the opposing intake side 104.

[0036] This embodiment utilizes a uniquely curved arc adjacent to the stepped section 310 to help actively control turbulent vortices or vortices generated at the stepped section 310. Specifically, the first arc section 152 and the second arc section 154 are combined and the Coanda effect is used to actively redirect the fluid flow toward reattachment to the wing surface. The Coanda effect refers to the tendency for a jet of fluid flowing out of an orifice to pull in surrounding fluid as it follows an adjacent flat or curved surface, creating a low-pressure region. The vortex 320 (and / or turbulent vortex) at the stepped section 310 forms a pressure difference between the second arc section 154 and the wing trailing section 122. The active fluid flowing on the opposing suction side forms an air curtain 322 (by the Coanda effect), which helps to hold the vortex 320 in place and keep it attached to the opposing suction side 104. Thus, the air curtain 322 provides a stabilizing force to hold the vortex 320 in place, which further helps prevent the boundary layer from separating from the blade 100.

[0037] This configuration provides a blade that maintains enough airflow to fix the airflow to the opposing intake side 104 and change the direction of the airflow by nearly 90 degrees. That is, the air that initially flowed in the first direction 300 flows away from the trailing edge 112 and into the second direction 302 upon encountering the leading edge 110. In some cases, the second direction 302 may be about 90 degrees from the first direction 300. Thereafter, the blade is pushed in a direction substantially opposite to the second direction 302. If the blade is included in a rotating turbine blade set, this change in airflow direction generates an opposing force that drives the blade in a direction substantially 90 degrees from the direction of the airflow in which the blade is positioned, potentially maximizing the amount of airflow converted into rotational energy. This may maximize the amount of power generated by such a turbine blade set. In other embodiments, depending on the shape and local curvature of the various segments of the blade 100, the direction of the incoming air can be changed by any angle in the range of about 10 to 90 degrees.

[0038] In various embodiments, the blades disclosed herein can be manufactured from a variety of materials. Exemplary materials, but are not limited to, materials known to be used in the manufacture of turbine blades, such as U-500, Rene 77, Rene N5, Rene N6, PWA1484, CMSX-4, CMSX-10, Inconel, GTD-111, EPM-102, Nominic 80a, Niminic 90, Nimonic 105, and Nimonic 263. Other materials include ceramic matrix composites. Other materials for blades, but are not limited to, aluminum, composites, steel, titanium, and other materials.

[0039] The wings can be manufactured using any known method. In some embodiments, the wings can be formed using an extrusion process.

[0040] The dimensions of the wing can be modified according to its intended use. The length, width, and thickness of the chords can be changed in various proportions while maintaining the overall contour shape of the wing.

[0041] A turbine blade set having blades with the above-described airfoil shape may be used in a ram-air turbine. Such a ram-air turbine may be configured for use in an aircraft. In some embodiments, the ram-air turbine may be permanently housed within the aircraft's body shell. Conduits can guide air from the airflow around the aircraft into the body shell, into the internal ram-air turbine, and out of the body shell.

[0042] Figure 6 is a schematic diagram of an aircraft including an enlarged view of the externally exposed components of the ram air turbine system. As shown in Figure 6, the aircraft 600 may include the ram air turbine system 602. The aircraft 600 may also include the body shell 605. The system 602 may be installed in any suitable location on the aircraft 600. For example, in some embodiments, the system 602 may be installed inside the fuselage. In another embodiment, the system 602 may be installed in the wing. Furthermore, in some embodiments, the system 602 may be installed within the flap track fairing, as shown in Figure 6. The airflow adjacent to the flap track fairing is usually smooth and therefore desirable for the placement of the ram air turbine system. This is because it produces a consistent output which is advantageous for generating a stable hydraulic volume. However, it will be understood that other locations may also be suitable for the disclosed ram air turbine system.

[0043] As shown in Figure 6, the system 602 may include an air inlet 610 into which air can flow in from the airflow outside the body shell 605, as indicated by arrow 625. The air entering through the air inlet 610 may be directed to a ram air turbine located inside the body shell 605 (see Figure 7). The air inlet 610 may have any suitable shape to smooth the airflow supplied to the ram air turbine. Slopes, curves, and other shapes may be used on the surface inside and around the air inlet 610 to affect the aerodynamic characteristics of the airflow supplied to the ram air turbine. The size of the air inlet 610 may be suitable for supplying the ram air turbine with an airflow having the volume, velocity, and consistency desired for the operation of the ram air turbine.

[0044] In some embodiments, an air scoop 620 may direct additional airflow to the air inlet 610. In some embodiments, the air scoop 620 may be deployable. Thus, in a non-deployed position (not shown), the air scoop 620 may be flush or substantially flush with the outer surface of the body shell 605. In the deployed position, as shown in Figure 6, the air scoop 620 may collect air and direct or guide it to the air inlet 610. The air scoop 620 may include appropriate features to provide airflow at a desired speed and consistency for the operation of the ram air turbine. The air scoop 620 may be formed of any suitable material such as carbon fiber, aluminum, titanium, steel, stainless steel, or any other material having the strength and rigidity to deploy in the airflow around the aircraft on which it is implemented.

[0045] The deployment mechanism for the air scoop 620 is not shown. Any suitable deployment mechanism can be used to deploy the air scoop 620, and it will be understood by those skilled in the art that a mechanism suitable for deploying the air scoop into the airflow at a given aircraft speed is obvious. Since the air scoop 620 is simpler than any ram air turbine, the deployment mechanism for the air scoop 620 can be made smaller in size, weight, and / or complexity compared to the deployment mechanism for a ram air turbine.

[0046] Furthermore, as also shown in Figure 6, the body shell 605 may include an air outlet 615. Air exiting the ram air turbine within the body shell 605 may be led out through the air outlet 615. Therefore, to facilitate the airflow through the ram air turbine, the air inlet 610 and the air outlet 615 may be spaced apart from each other in the aircraft's direction of flight. The two ports do not necessarily have to be directly in a straight line with each other, but the airflow through the ram air turbine is facilitated if the air inlet 610 is located further forward toward the front of the aircraft 600 and the air outlet 615 is located further aft toward the rear of the aircraft 600.

[0047] Although not shown in Figure 6, in some embodiments, the air outlet 615 may include a closure plate or other structure to close it when the ram air turbine is not in use. In some cases, the operation of the closure plate may be mechanically linked to the deployment of the air scoop 620. Other mechanisms such as spring biasing or pneumatics may be used to open the closure plate as needed.

[0048] Figure 7 is a schematic diagram showing the interior of an aircraft body shell 605, illustrating the components of a ram air turbine system 602. As shown in Figure 7, the system 602 may include an intake conduit 611 configured to lead air from an air inlet 610 within the body shell 605 to a ram air turbine, which may be housed within a ram air turbine housing 700. Furthermore, the system 602 may include an outlet conduit 616 configured to lead air exiting the ram air turbine to an air outlet 615 within the body shell 605. The shape, size, and material of the air intake conduit 611 and the outlet conduit 616 may be selected accordingly to supply airflow to the ram air turbine in the desired quantity, velocity, and smoothness.

[0049] Therefore, in some embodiments, the ram air turbine may be permanently housed within the aircraft's body shell 605. Furthermore, the generator may be associated with and driven by the ram air turbine. Thus, the generator housing 705 may be configured to permanently house the generator within the aircraft's body shell 605.

[0050] By keeping the ram air turbine inside the aircraft and deploying only the air scoop, weight savings are achieved because the air scoop deployment mechanism is lighter than the ram air turbine. Furthermore, the deployed air scoop itself may experience less drag than a ram air turbine deployed in the airflow.

[0051] Figure 8 is a schematic rear view of a ram air turbine 800 according to an exemplary embodiment. As shown in Figure 8, the ram air turbine 800 may have an upstream end 805 and a downstream end 810. Therefore, the ram air turbine 800 may be configured to receive air flowing through the ram air turbine 800 from the upstream end 805 to the downstream end 810.

[0052] Furthermore, the ram air turbine 800 may include an outer housing 820. In some embodiments, the outer housing may be tapered. For example, as shown in Figure 8, the outer housing 820 may have a larger diameter at the downstream end 810 than at the upstream end 805.

[0053] Figure 8 also shows an output shaft 815 configured to be driven by a turbine blade set 825 within an outer housing 820. The output shaft 815 may ultimately drive a generator, a hydraulic pump, or both.

[0054] Figure 9 is a schematic diagram of an aircraft including an enlarged view of the externally exposed components of a ram air turbine system according to another embodiment. As shown in Figure 9, the aircraft may include a ram air turbine system 902. The aircraft may also include a body shell 905. Like system 602, system 902 may be installed at any suitable location on the aircraft.

[0055] As shown in Figure 9, the system 902 may include an air inlet 910 into which air from the airflow outside the body shell 905 can flow, as indicated by arrow 925. The air entering the air inlet 910 may be directed to a ram air turbine located inside the body shell 905 (see Figure 7). Additional airflow may be directed to the air inlet 910 by an air scoop 920. In some embodiments, the air scoop 920 may be deployable. Thus, in a non-deployed position (not shown), the air scoop 920 may be flush or substantially flush with the outer surface of the body shell 905. In the deployed position, as shown in Figure 9, the air scoop 920 may collect and direct or guide air to the air inlet 910. The air scoop 920 may include appropriate features for providing airflow at a desired speed and consistency for the operation of the ram air turbine. The air scoop 920 may be formed from any suitable material such as carbon fiber, aluminum, titanium, steel, stainless steel, or any other material having the strength and rigidity to deploy in the airflow around the aircraft on which it is implemented.

[0056] The deployment mechanism for the air scoop 920 is not shown. Any suitable deployment mechanism can be used to deploy the air scoop 920, and it will be obvious to those skilled in the art that a mechanism suitable for deploying the air scoop into the airflow at a given aircraft speed is obvious.

[0057] Furthermore, as also shown in Figure 9, the body shell 905 may include an air outlet 915. Air exiting the ram air turbine within the body shell 905 may be led out through the air outlet 915. Therefore, to facilitate the airflow through the ram air turbine, the air inlet 910 and the air outlet 915 may be spaced apart from each other in the aircraft's direction of flight. The two ports do not necessarily have to be directly in a straight line with each other, but the airflow through the ram air turbine is facilitated if the air inlet 910 is located further forward toward the front of the aircraft 900 and the air outlet 915 is located further aft toward the rear of the aircraft 900.

[0058] In addition to the airflow that flows into the air inlet 910 and through the RAT within the aircraft body shell 905, the airflow through the system is also driven by the Venturi effect at the air outlet 915. The Venturi effect drives the airflow through the system 602, but this effect may be mitigated by the presence of an air scoop 620 aligned with the outlet 615 in the direction of the airflow. To maximize the Venturi effect, in some embodiments the outlet may be spaced apart in the direction of the airflow or positioned laterally. For example, as shown in Figure 9, the outlet 915 may be spaced laterally apart from the air inlet 910, as indicated by arrow 935. Thus, as indicated by arrow 940, a clean airflow flows over the outlet 915 without interruption by the air scoop 920.

[0059] In some embodiments, the internal RAT system may also include a fluid accelerator at the inlet to increase the velocity of the air supplied to the RAT. The accelerators described herein are called “fluid” accelerators because they are useful for both gases and liquids. In aerospace applications such as RATs, “fluid” accelerators may also be called “air” accelerators.

[0060] Figure 10 is a schematic diagram of an aircraft including an enlarged view of externally exposed components of a ram air turbine system according to another embodiment. As shown in Figure 10, the aircraft 1000 may include an internal ram air turbine system 1002. The system 1002 may include an air inlet 1010 and an air outlet 1015. The system 1002 may also include an air scoop 1020 configured to direct air into the air inlet 1010, as indicated by arrow 1025. The air exiting the air outlet 1015 is indicated by arrow 1030. As shown in Figure 10, the air outlet 1015 may be spaced laterally from the air inlet 1010 so that a turbulent airflow, indicated by arrow 1040, flows over the air outlet 1015, as indicated by arrow 1035, creating a Venturi effect.

[0061] Other features of system 1002 (Figure 10) may be the same as or similar to those of systems 602 and 902 described above. Furthermore, system 1002 may include a fluid accelerator 1050 located at the inlet 1010. Any suitable fluid accelerator may be used in system 1002. Exemplary features of such a fluid accelerator are described in more detail below.

[0062] Figure 11 is a schematic front perspective view of a fluid accelerator according to an exemplary embodiment. As shown in Figure 11, the fluid accelerator 1100 may include an outer housing 1105 having an inlet end 1110 and an outlet end 1115. The fluid is accelerated as it flows from the inlet end 1110 to the outlet end 1115.

[0063] The outer housing 1105 may be made of any suitable material such as metal, plastic, composite material, or other manufacturing material. Although the outer housing 1105 is shown to have a circular cross-section, specific parts of the outer housing 1105 may have different cross-sectional shapes.

[0064] Multiple fluid acceleration components may be arranged within the outer housing 1105. For example, as shown in Figure 11, the fluid accelerator 1100 may include an annular ring 1130 which may have an airfoil cross-sectional shape. Furthermore, the fluid accelerator 1100 may include a turbine wheel 1150 which includes both turbine blades and compressor blades.

[0065] As shown in Figure 11, the outer housing 1105 may include an inlet 1120 and an outlet 1125. In some embodiments, the outer housing 1105 may define a converging nozzle near the inlet end 1110. For example, as shown in Figure 11, the inlet 1120 of the outer housing 1105 may be a converging nozzle. That is, as shown in Figure 11, the inlet 1120 may be conical with a diameter that substantially decreases along the direction of fluid flow. Within the converging nozzle of the inlet 1120 of the outer housing 1105, the annular ring 1130 may be located near the inlet end 1110.

[0066] As shown in Figure 11, the annular ring 1130 may be positioned near the inlet end 1110 of the outer housing 1105 within the converging nozzle of the outer housing 1105. Also shown in Figure 11, the annular ring 1130 may be spaced apart from the outer housing 1105 by a plurality of spacer mountings 1135, as indicated by arrow 1140. Any appropriate number of spacer mountings 1135 may be used to support the annular ring 1130. For example, a more flexible and / or delicate annular ring may require more spacer mountings, while a more robust annular ring may be provided with fewer spacer mountings. The distance between the annular ring 1130 and the outer housing 1105, indicated by arrow 1140, may be determined based on the use of the fluid accelerator 1100. This distance may be selected according to the intended use of the device, along with various other parameters such as the shape of the blades, the size of the blades, and the angle of the converging nozzle. Factors determining these parameters may include the type of fluid (air, gas, liquid, etc.), the velocity of the fluid flow entering the fluid accelerator, the desired velocity of the fluid flow leaving the fluid accelerator, and constraints on size and installation.

[0067] Figure 12 is a schematic diagram showing a rear perspective view of the downstream end of the fluid accelerator shown in Figure 11. As shown in Figure 12, the fluid accelerator 1100 may include a mounting cross member 1155 for the turbine wheel 1150. As shown in Figure 12, the mounting cross member 1155 may include a peripheral ring 1160 which may be attached to the outer housing 1105. Furthermore, the mounting cross member 1155 may have a central hub 1170 connected to the peripheral ring 1160 by a plurality of supports 1165. The central hub 1170 may have a central hole 1175 configured to receive a connecting shaft 1300 (see Figure 13). To mount the turbine wheel 1150 inside the outer housing 1105, the connecting shaft 1300 may be received in the central hole 1175 and central opening 1180 of the turbine wheel 1150. When installed, the turbine wheel 1150 can rotate freely within the outer housing 1105, while the mounting cross member 1155 is fixed to the outer housing 1105.

[0068] Figure 13 is a schematic rear perspective exploded view of the fluid accelerator shown in Figure 11. As shown in Figure 13, the turbine wheel 1150 may be attached to the mounting cross brace 1155 using a connecting shaft 1300. The connecting shaft 1300 is schematically shown in Figure 13. It will be understood that the connecting shaft 1300 may have any configuration suitable for rotatably connecting the turbine wheel 1150 to the mounting cross brace 1155. To enable the turbine wheel 1150 to rotate relative to the mounting cross brace 1155, one or more bushings, bearings, or other rotatable connecting devices may be provided at the central opening 1180 of the turbine wheel 1150, the central hole 1175 of the mounting cross brace 1155, the upstream end of the connecting shaft 1300, and / or the downstream end of the connecting shaft 1300.

[0069] The annular ring 1420 may have any suitable vane such that the suction side is generally inclined downstream toward the radially outward direction and the pressure side is inclined upstream toward the radially inward direction. In some embodiments, the annular ring 1420 may have a vane shape configured as described above with respect to Figures 1 and 5. That is, the annular ring 1420 may have a hook-shaped cross-section.

[0070] Figure 14 is a schematic perspective view of a cutaway section of the nozzle of the fluid accelerator shown in Figure 11. As shown in Figure 14, the annular ring 1130 has a leading edge 1400 and a trailing edge 1405. Furthermore, the annular ring 1130 has an airfoil-shaped suction side 1420 and an airfoil-shaped pressure side 1425. As further shown in Figure 14, the annular ring 1130 may be angled such that the airfoil-shaped suction side 1420 is inclined downstream toward the outlet end 1115 of the outer housing 1105, and the airfoil-shaped pressure side 1125 is inclined upstream toward the inlet end 1110 of the outer housing 1105.

[0071] In some embodiments, lines extending through the leading and trailing edges of the annular ring may be substantially parallel to the inner surface of the converging nozzle near the inlet end of the outer housing. For example, the inclination of the annular ring 1130 is shown in Figure 14 by the blade axis 1410 extending through the leading edge 1400 and trailing edge 1405 of the annular ring 1130. In particular, the blade axis 1410 is angled with respect to the central axis 1430 passing through the outer housing 1105.

[0072] As shown in Figure 14, in some embodiments, the blade axis 1410 may be substantially parallel to the inner surface 1415 of the converging nozzle formed by the inlet 1120 of the outer housing 1105.

[0073] Furthermore, for reference, Figure 14 shows that at the inlet end 1110, the outer housing 1105 has a first radius 1435, and in the neck region 1440 between the inlet portion 1120 and the outlet portion 1125, the outer housing 1105 may have a second radius 1445 which is smaller than the first radius 1435. Thus, the inlet portion 1120 forms a converging nozzle.

[0074] The fluid accelerator may include a turbine wheel located in an outer housing downstream of the annular ring, in addition to an annular ring having an airfoil cross-sectional shape. The turbine wheel may include a plurality of turbine blades oriented to rotate the turbine wheel in a first direction around its central axis, driven by the fluid flow through the turbine wheel. Furthermore, the turbine wheel may include a plurality of compressor blades positioned to propel the fluid downstream when the turbine wheel is rotated in the first direction. To produce this effect, the turbine blades are positioned radially outward of the compressor blades. Thus, the torque generated by the turbine blades is increased because they are positioned further away from the central axis of the turbine wheel. Larger moment arms with longer radii generate higher torque.

[0075] Figure 15 is a schematic perspective view of a cutaway section of the nozzle and turbine wheel of the fluid accelerator shown in Figure 11. As shown in Figure 15, the turbine wheel 1150 may be located within an outer housing 1105 downstream of the annular ring 1130. The turbine wheel 1150 may include an inner hub 1500 having a central axis 1430, an outer ring 1505 concentric with the inner hub 1500, and an intermediate ring 1510 concentrically positioned between the inner hub 1500 and the outer ring 1505. Furthermore, the turbine wheel 1150 may include a plurality of turbine blades 1515 extending between the intermediate ring 1510 and the outer ring 1505. The turbine blades 1515 may be oriented to rotate the turbine wheel 1150 in a first direction around the central axis 1430, driven by the fluid flow through the turbine wheel 1150, as indicated by arrow 1525. In the embodiments described herein, the turbine wheel 1150 may be configured to be driven counterclockwise (when viewed from the upstream side of the turbine wheel) by the turbine blades 1515, as indicated by arrow 1525. However, it will be understood that in other embodiments, the turbine wheel may be configured to be driven clockwise. The turbine wheel may be driven clockwise simply by reversing the orientation of the turbine blades.

[0076] As shown in Figure 15, the turbine wheel 1150 may include a plurality of compressor blades 1520 extending between the inner hub 1500 and the intermediate ring 1510. The compressor blades 1520 may be oriented to drive the fluid downstream when the turbine wheel 1150 is rotated by the turbine blades 1515 in a first direction (arrow 1525).

[0077] Figure 16 is a schematic cutaway cross-sectional perspective view of the fluid accelerator 1100. Figure 16 shows the fluid accelerator 1100 with a mounting cross brace 1155 located within the outer housing 1105. Figure 16 does not show the fasteners used to attach the mounting cross brace 1155 to the outer housing 1105. It will be understood that the mounting cross brace 1155 can be fixedly or detachably attached to the outer housing 1105 using any suitable type of fastener, such as bolts or rivets. Also, Figure 16 omits the connecting shaft between the turbine wheel 1150 and the mounting cross brace 1155. As described above, it will be understood that the connecting shaft is used to attach the turbine wheel 1150 to the mounting cross brace 1155 within the outer housing 1105. (See also Figure 13).

[0078] Figure 17 is a schematic cutaway cross-sectional perspective view of the outer housing 1105 and annular ring 1130 of the fluid accelerator 1100, showing the fluid flow pattern affected by the outer housing 1105 and annular ring 1130. There are several ways in which the outer housing 1105 and annular ring 1130 accelerate the fluid flow through the fluid accelerator.

[0079] The airfoil shape of the annular ring 1130 accelerates the air flowing over the suction side 1420. This reduces the pressure near the suction side 1420 of the annular ring 1130, resulting in several effects. In particular, this pressure reduction on the suction side 1420 of the annular ring 1130 draws fluid into this reduced pressure region from multiple locations.

[0080] Firstly, this pressure reduction draws fluid in from outside the radius of the inlet end 1110 of the outer housing 1105. This is indicated by the first streamline 1701. As shown in Figure 17, the first streamline begins at a radius larger than the inlet end 1110. Without the pressure reduction at the suction side 1420 of the annular ring 1130, the fluid at the starting point of the first streamline 1701 would simply bypass the outer edge of the inlet end 1110. However, this pressure reduction draws the fluid in from this peripheral region outside the radius of the inlet end 1110. Thus, essentially more fluid passes through the inlet end 1110 compared to the case where the annular ring 1130 was not placed inside the outer housing 1105. By pushing more fluid into an opening of a given size, the fluid is accelerated. This is indicated by the increase in dash length as the first fluid streamline 1701 enters the outer housing 1105.

[0081] Secondly, this pressure reduction on the suction side 1420 of the annular ring 1130 is located in the region between the annular ring 1130 and the inlet end 1110 of the outer housing 1105. Thus, as shown in Figure 17, the second fluid streamline 1702 accelerates the fluid flowing directly into the space 1140 between the annular ring 1130 and the inlet end 1110 of the outer housing 1105. The increase in fluid velocity is indicated by the increase in the length of the dash of the second fluid streamline 1702 as it passes through the suction side 1420 of the annular ring 1130.

[0082] Furthermore, the inclination of the annular ring 1130 causes the pressure side 1425 of the annular ring 1130 to form a converging nozzle. Thus, the fluid flowing near the pressure surface 1425 of the annular ring 1130 is accelerated. This is shown by the third fluid channel 1703. As shown in Figure 17, the dash of the third fluid streamline 1703 lengthens as the fluid passes through the pressure side 1425 and converges. The effect of this converging nozzle formed by the inclined pressure side 1425 of the annular ring 1130 decreases as the fluid flow moves radially inward from the annular ring 1130. For example, the fourth fluid streamline 1704 shows an increase in velocity, but the length of the dash does not increase to the same extent as the length of the third fluid streamline 1703. The fifth fluid streamline 1705 shows less acceleration than the fourth fluid streamline 1704. The sixth fluid streamline 1706 and the seventh fluid streamline 1707 show gradually decreasing acceleration. Furthermore, the eighth fluid streamline 1708 near the central axis 1430 of the outer housing 1105 exhibits the least acceleration.

[0083] In addition to the fluid acceleration provided by the convergent nozzles on the suction side 1420 and the angled pressure side 1425 of the annular ring 1130, additional acceleration is also provided by the convergent nozzle configuration at the inlet 1120 of the outer housing 1105. Thus, the fluid streamlines downstream of the annular ring 1130 exhibit further acceleration, which also decreases with radial distance from the outer housing 1105. Therefore, the combination of the convergent nozzles on the outer housing 1105 and the inclined airfoil shape of the annular ring 1130 results in significant fluid acceleration, with the maximum acceleration occurring at the radially outermost part of the fluid flow cavity.

[0084] The fluid acceleration obtained by the combination of the converging nozzle of the outer housing 1105 and the annular ring 1130 is greatest in the radially outward direction. However, since the turbine blades are located radially outward and are driven by the fluid flow pre-accelerated by the converging nozzle of the outer housing 1105 and the annular ring 1130, it is beneficial to further combine this system with a turbine wheel 1150.

[0085] Figure 18 is a schematic diagram of a cutaway cross-section of the turbine wheel 1150. Figure 18 shows exemplary orientations of the turbine blades 1515 and compressor blades 1520. Furthermore, Figure 18 also shows the effect of the turbine wheel 1150 on the fluid flowing through the turbine blades 1515 and compressor blades 1520.

[0086] As shown in Figure 18, the turbine wheel 1150 has an inlet side 1801 and an outlet side 1802. Therefore, Figure 18 shows the upstream direction 1803 and the downstream direction 1804.

[0087] The turbine blade 1515 may have any suitable airfoil shape. In some embodiments, the turbine blade 1515 may have an airfoil shape configured as described above with respect to Figures 1 to 5. That is, the turbine blade 1515 may have a hook-shaped cross-section, as shown in Figure 18.

[0088] As shown in Figure 18, the turbine blade 1515 may be angled such that the suction side 1870 of the airfoil shape is inclined downstream toward the outlet side 1802 of the turbine wheel 1150, and the pressure side 1875 of the airfoil shape is inclined upstream toward the inlet side 1801 of the turbine wheel 1150. For example, as shown in Figure 18, the turbine blade 1515 may each have a leading edge 1855 and a trailing edge 1860. An axis 1865 passing through the leading edge 1855 and the trailing edge 1860 defines a line indicating the inclination angle of the turbine blade 1515.

[0089] The compressor blade 1520 may have any suitable airfoil shape. In some embodiments, the compressor blade 1520 may have an airfoil shape configured as described above with respect to Figures 1 to 5. That is, the compressor blade 1520 may have a hook-shaped cross-section, as shown in Figure 18.

[0090] As shown in Figure 18, the compressor blade 1520 may be angled such that the pressure side 1892 of the airfoil cross-section is inclined downstream toward the outlet side 1802 of the turbine wheel 1150, and the suction side 1895 of the airfoil cross-section is inclined upstream toward the inlet side 1801 of the turbine wheel 1150. For example, as shown in Figure 18, the compressor blade 1520 may have a leading edge 1880 and a trailing edge 1885, respectively. An axis 1890 passing through the leading edge 1880 and the trailing edge 1885 defines a line indicating the inclination angle of the compressor blade 1520.

[0091] The turbine blades and compressor blades may be angled at any appropriate angle as described above. In some embodiments, the turbine blades and compressor blades may be angled such that lines extending through the leading and trailing edges of the turbine blades are parallel to lines extending through the leading and trailing edges of the compressor blades located radially inward from the turbine blades.

[0092] Figure 18 shows the effect of the turbine wheel 1150 on the fluid flow through different regions of the turbine wheel 1150. As shown in Figure 18, the annular outer region 1810 is defined between the outer ring 1505 and the intermediate ring 1510. The fluid flow through the outer region 1810 of the turbine wheel 1150 passes through the turbine blades 1515. Furthermore, the annular inner region 1815 is defined between the intermediate ring 1510 and the inner hub 1500. The fluid flow through the inner region 1815 of the turbine wheel 1150 passes through the compressor blades 1520.

[0093] More specifically, the fluid flow introduced through the outer region 1810 is represented by arrow 1820. This fluid flowing through the outer region 1810 around the turbine blade 1515 drives the turbine wheel 1150 in a counterclockwise direction 1840. By converting the energy from the fluid flow into rotational motion of the turbine wheel 1150, the velocity of the fluid flow exiting the outlet side 1802 of the outer region 1810 is slower than that of the inlet side 1801 of the outer region 1810, as shown by the smaller arrow 1845.

[0094] The fluid flow introduced through the inner region 1815 is represented by arrow 1825. Due to the orientation of the compressor blade 1520, this fluid flow is drawn through the inner region 1815 by the compressor blade 1520 and thus propelled downstream 1804 from the outlet side 1802 of the inner region 1815. The larger arrow 1850 indicates an increase in the velocity of the fluid flow exiting the inner region 1815, compared to the smaller arrow 1825 which indicates air entering the inner region 1815.

[0095] Therefore, fluid flowing at the same velocity through the outer region 1810 and the inner region 1815 results in slower fluid exiting the outer region 1810 and faster fluid exiting the inner region 1815. As shown in Figure 18, arrow 1820, representing the fluid flow through the outer region 1810, flows along the outer radius 1830 from the central axis 1430, while arrow 1825, representing the fluid flow through the inner region 1815, flows along the inner radius 1835, which is smaller than the outer radius 1830. Because the turbine blade 1515 is located radially further from the central axis 1430 of the turbine wheel 1150 than the compressor blade 1520, the fluid flowing through the outer region 1810 generates a greater torque than is needed to propel the fluid through the inner region 1815. This accelerates the overall total airflow through the turbine wheel 1150.

[0096] Therefore, when the turbine wheel 1150 is placed in the fluid flow, it accelerates the fluid flow. When the outer housing and airfoil annular ring of the fluid accelerator 1100 are combined, the fluid flow becomes even greater. As described above with respect to Figure 17, the fluid flow in the radially outer region is most accelerated by the outer housing and annular ring. Therefore, this fluid in the radially outer region has even greater energy to drive the turbine blades 1515 of the turbine wheel 1150, thereby increasing the thrust of the fluid passing through the inner region 1815.

[0097] These three fluid acceleration components (i.e., 1: the outer housing with the converging nozzle, 2: the airfoil annular ring within the outer housing, and 3: the turbine wheel described above) each provide fluid acceleration individually, but when combined, they provide greater fluid acceleration. Furthermore, these fluid acceleration components can be implemented to accelerate fluids in a variety of environments. The above describes an exemplary use at the inlet of a ram air turbine. Another exemplary use of such a fluid accelerator is at the inlet of a jet engine.

[0098] Figure 19 is a schematic diagram of an aircraft with a fluid accelerator attached to the inlet of a turbine engine. As shown in Figure 19, the aircraft 1900 may include one or more jet engines 1905. The inlets of such one or more jet engines may include a fluid accelerator 1910 which may have the same or similar configuration as the fluid accelerator 1100 described above. Such a fluid accelerator implementation may allow the air entering the jet engine to be pre-accelerated, potentially enabling the engine to generate more thrust.

[0099] While various embodiments of the present invention have been described, this description is illustrative and not limiting, and it will be apparent to those skilled in the art that many more embodiments and implementations are possible within the scope of the invention. Unless otherwise specifically excluded, any element of any embodiment can be replaced with another element of another embodiment, or added to another embodiment. Therefore, the present invention is not limited except with regard to the appended claims and their equivalents. Furthermore, various modifications and changes can be made within the scope of the appended claims. [Explanation of Symbols]

[0100] 1100 Fluid Accelerator

Claims

1. A fluid accelerator that utilizes energy from a flowing fluid, It comprises an outer housing having an inlet end and an outlet end, the outer housing having a converging nozzle set near the inlet end, A fluid accelerator further comprising an annular ring having an airfoil cross-sectional shape, disposed within the converging nozzle near the inlet end of the outer housing.

2. The annular ring has an suction side with the airfoil cross-sectional shape and a pressure side with the airfoil cross-sectional shape, The fluid accelerator according to claim 1, wherein the annular ring is angled such that the suction side of the airfoil cross-section is inclined downstream toward the outlet end, and the outlet end of the airfoil cross-section is inclined upstream toward the suction side.

3. The annular ring has a leading edge and a trailing edge. The lines extending through the front edge and the rear edge are substantially parallel to the inner surface of the converging nozzle near the entrance end of the outer housing. The fluid accelerator according to claim 2.

4. The annular ring has a leading edge, a trailing edge, an suction side, and a pressure side, and the airfoil cross-sectional shape is, A base including a first surface related to the pressure side and a second surface related to the suction side, An overhang portion extending over a part of the base, It includes the base portion and the elliptical portion connecting the overhang portion adjacent to the leading edge, The fluid accelerator according to claim 1, wherein the overhang portion is curved toward the second surface of the base portion.

5. The fluid accelerator according to claim 4, wherein the overhang portion comprises a first arc portion having a first radius of curvature on the suction side, and the overhang portion comprises a second arc portion having a second radius of curvature different from the first radius of curvature on the suction side.

6. The fluid accelerator according to claim 4, wherein the second radius of curvature is larger than the first radius of curvature.

7. The fluid accelerator according to claim 4, wherein the free end of the overhang portion is separated from the base portion by a gap, the gap being substantially larger than the local thickness of the overhang portion.

8. The fluid accelerator according to claim 7, wherein the gap is at least twice the size of the local thickness of the overhang portion.

9. A fluid accelerator, An outer housing having an inlet end and an outlet end, wherein the outer housing defines a nozzle near the inlet end, A fluid accelerator comprising the nozzle and an annular ring disposed near the inlet end of the outer housing, The aforementioned annular ring has an airfoil cross-sectional shape, The annular ring has a leading edge, a trailing edge, an suction side, and a pressure side, and the airfoil cross-sectional shape is, A base including a first surface related to the pressure side and a second surface related to the suction side, An overhang portion extending over a part of the base, It includes the base portion and the elliptical portion connecting the overhang portion adjacent to the leading edge, A fluid accelerator in which the overhang portion is curved toward the second surface of the base.

10. The fluid accelerator according to claim 9, wherein the overhang portion comprises a first arc portion having a first radius of curvature on the suction side, and the overhang portion comprises a second arc portion having a second radius of curvature different from the first radius of curvature on the suction side.

11. The fluid accelerator according to claim 9, wherein the second radius of curvature is larger than the first radius of curvature.

12. The fluid accelerator according to claim 9, wherein the free end of the overhang portion is separated from the base portion by a gap, the gap being substantially larger than the local thickness of the overhang portion.

13. The fluid accelerator according to claim 12, wherein the gap is at least twice as large as the local thickness of the overhang portion.

14. A fluid accelerator, An outer housing having an inlet end and an outlet end, wherein the outer housing defines a nozzle near the inlet end, A fluid accelerator comprising an annular ring disposed within the nozzle near the inlet end of the outer housing, The aforementioned annular ring has an airfoil cross-sectional shape, The annular ring has an suction side with the airfoil cross-sectional shape and a pressure side with the airfoil cross-sectional shape, A fluid accelerator in which the annular ring is angled such that the suction side of the airfoil cross-section is inclined downstream toward the outlet end, and the pressure side of the airfoil cross-section is inclined upstream toward the inlet end.

15. The annular ring has a leading edge, a trailing edge, an suction side, and a pressure side, and the airfoil cross-sectional shape is, A base including a first surface related to the pressure side and a second surface related to the suction side, An overhang portion extending over a part of the base, It includes the base portion and the elliptical portion connecting the overhang portion adjacent to the leading edge, The fluid accelerator according to claim 14, wherein the overhang portion is curved toward the second surface of the base portion.

16. The fluid accelerator according to claim 15, wherein the overhang portion comprises a first arc portion having a first radius of curvature on the suction side, and the overhang portion comprises a second arc portion having a second radius of curvature different from the first radius of curvature on the suction side.

17. The fluid accelerator according to claim 15, wherein the second radius of curvature is larger than the first radius of curvature.

18. The free end of the overhang portion is separated from the base by a gap, and the gap is substantially larger than the local thickness of the overhang portion. The fluid accelerator according to claim 15.

19. The fluid accelerator according to claim 18, wherein the gap is at least twice as large as the local thickness of the overhang portion.

20. The annular ring has a leading edge and a trailing edge. The line extending through the front edge and the rear edge is substantially parallel to the inner surface of the nozzle near the inlet end of the outer housing. The fluid accelerator according to claim 14.

Images