Pneumatic collapsible ejector supply system for aircraft propulsion

Abstract

The propulsion system includes at least one conduit configured to carry and distribute motive fluid, the conduit further configured to contract when no motive fluid is supplied from the compressor and inflate when motive fluid is supplied from the compressor; and at least one ejector in fluid communication with the at least one conduit, where the compressor supplies compressed air to the at least one ejector to generate thrust, and where, when not in use, the at least one ejector is retractable into the volume of the wing to streamline the exterior of the wing.

Description

[0001] Copyright

[0002] This disclosure is protected by U.S. and / or international copyright laws. ©2023 JETOPTERA CORPORATION All rights reserved. Portions of this patent document disclosure contain material that is copyrighted. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure as it appears in the Patent and / or Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever.

[0003] Priority claim

[0004] This application claims priority to U.S. Provisional Patent Application Serial No. 63 / 355,043, filed on June 23, 2022, the contents of which are hereby incorporated by reference as if fully set forth herein. Background Art

[0005] One of the biggest limitations of vertical take-off and landing (VTOL) aircraft is the forward speed at which these aircraft are capable. Rotorcraft use propellers and rotors particularly efficiently to produce very large hovering efficiencies, which are defined as the amount of vertical force (in pounds-force or Newtons) produced per unit of power (horsepower or Watts) used.

[0006] Helicopters fare well in this category, being able to hover and take off vertically in a very efficient manner, with hover efficiencies in the 5lbf / hp to 12lbf / hp (or 3kg / kW-7.5kg / kW) range. However, their forward speeds are extremely limited compared to other aircraft, as the forward speed of the rotor is limited by the transition to potentially supersonic airflow over the advancing blade tip, while the speed of the retreating blade is well below the local speed of supersonic, incurring losses.

[0007] To overcome the forward speed limitation, some manufacturers have introduced compound helicopters, which use a dedicated fan or rotor to propel the helicopter forward, with the rotor used only for vertical lift. However, even this approach has serious limitations and the fastest compound helicopters cannot exceed 250 knots and can only fly at high altitudes.

[0008] To overcome this problem, rotorcraft manufacturers introduced tilt-rotors. The advantage of tilt-rotors is that they can minimize the weight of the power plant required to propel the aircraft at high speed while still providing vertical flight propulsion. However, tilt-rotors are complex and have weaknesses in the control and synchronization of the rotors. The maximum forward speed that a tilt-rotor can achieve at very high altitudes is 320 knots, and no more than 250 knots at sea level.

[0009] I hope to have a vertical take-off and landing aircraft that can break the speed limit. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 shows an ejector and an inflated catheter in a deployed position according to an embodiment; and

[0011] Figure 2 The ejector is shown in a retracted position and the deflated catheter according to an embodiment. DETAILED DESCRIPTION

[0012] The embodiments of the present invention are applicable to vertical take-off and landing aircraft, short field take-off and landing aircraft, and conventional take-off and landing aircraft.

[0013] Fluid Propulsion Systems (FPS) are propulsion systems that can be integrated into and become part of an aircraft wing. In addition to being able to use these FPS ejectors as a boundary layer control (BLC) system and increase lift, this approach can also allow the wing supporting these thrusters (which may be non-circular in shape) to have a triple stall margin (i.e., be able to operate at higher angles of attack) where otherwise the net shape wing would stall through boundary layer separation on the suction side.

[0014] Accelerating to higher speeds in level flight remains a challenge, as the ejector is no longer efficient at higher speeds and the protrusion created by the ejector on the wing creates significant drag, preventing the aircraft from exceeding 200 knots.

[0015] Therefore, it is advantageous to implement a method of stowing these ejectors into the wing, thereby enabling smoother acceleration and lower drag coefficients at higher speeds. In addition, the stowage of the ejectors may actually require a wing of great thickness that can accommodate these ejectors. Since the ejectors are also supplied via an aerodynamic network of pipes and ducts, these pipes and ducts connect, for example, a turbocompressor for compressed air to the propeller-ejectors. When in use, the network is pressurized by the power air supplied to the propellers and not pressurized when not in use. Therefore, the volume formed by the pipes or ducts, which needs to be large enough to minimize losses, occupies a large space in the wing. It is ideal to minimize this space in order to allow the use of thinner wing sections, which in turn allows faster forward flight speeds.

[0016] Embodiments of the present invention combine the flexible material used for such conduits 102, which may be made of a soft but reliably resilient material (e.g. silicone) capable of undergoing multiple cycles of compression and extension, with the geometry of the wing 110, and the structure of the fluid propulsion system used on the wing. That is, the wing contains a series of compartments 100 along its span containing inflatable material connected to the propellers 101, wherein the openings on the suction side of the wing and the compartments allow the propellers to be extended when in use, and retracted into the wing by compressing the unpressurized conduit until the entire body of the propeller is completely stowed within the wing.

[0017] In the case of a propeller, a mechanism 104 extends the propeller out of the wing while the duct 102 receives compressed motive air 111 from a compressor. The risk of clogging is minimized as the motive air 111 rapidly inflates the duct 102 and the propeller 101, thereby allowing the motive air to flow freely through the main nozzle. The mechanism for extending the propeller 101 can also be minimized as the compressed air assists this process. The propeller 101 is connected to the inflatable duct 102 by a known method of attaching a valve 103, for example similar to a tire in the automotive or truck industry. The duct 102 also has design features that allow minimal friction (and therefore minimal pressure loss) of the flow when fully inflated, while being able to fill non-circular, for example rectangular, wing compartments, so that the thickness of the wing can be minimized by avoiding the duct taking a circular shape.

[0018] The top 105 of the propeller 101 may have a plate that can perfectly seal against the suction side of the wing when the propeller is retracted. When extended, the plate may be shaped so that the configuration creates minimal drag.

[0019] When retracted, for example at 150 knots, using a valve system, the compressed air as the motive fluid can be used to directly propel the vehicle forward as a converging or converging diverging jet. With the thrusters retracted, the vehicle's lift-to-drag ratio is significantly increased, minimizing the need for greater horizontal thrust.

[0020] In one embodiment, by retracting the propellers into the wings, the lift-to-drag coefficient (L / D) of the aircraft 120 increases from 10 to 15, so the aircraft needs to reduce thrust by 1.5 times (1.5 times less) to maintain the current speed constant. However, by keeping the power level (i.e., the flow of power air expanding in the form of a jet) constant, the speed of the aircraft is significantly accelerated to over 150 knots, up to 300 knots to 400 knots, depending on the wing thickness and wing size. In this way, the forward speed can far exceed 100 knots or more for tiltrotors or any rotorcraft. When the propellers stop running, the valves force all the air to fill the duct network that feeds the propellers, and the high-speed nozzles are no longer functional (e.g., speeds below 150 knots); as the aircraft slows down, while the compressed air from the high-speed nozzles is delivered in a gradually increasing percentage to feed the propellers, the aircraft slows down and can eventually run on propellers alone, thereby relying entirely on FPS deceleration for vertical landing.

[0021] This application is intended to describe one or more embodiments of the present invention. It should be understood that the use of absolute terms (such as "must", "will", etc.) and specific numbers should be interpreted as applicable to such one or more embodiments, but not necessarily to all such embodiments. Therefore, embodiments of the present invention may omit or include modifications of one or more features or functions described in the context of these absolute terms. In addition, the titles in this application are for reference only and will not affect the meaning or interpretation of the present invention in any way.

[0022] Although the foregoing text sets forth detailed descriptions of many different embodiments, it should be understood that the scope of protection is limited by the wording of the appended claims. The detailed description should be understood only as exemplary and does not describe every possible embodiment, as it would be impractical or even impossible to describe every possible embodiment. Many alternative embodiments may be implemented using prior art or technology developed after the filing date of this patent application, which will still fall within the scope of the claims.

[0023] Therefore, many modifications and variations may be made to the techniques and structures described and illustrated herein without departing from the spirit and scope of the claims. Therefore, it should be understood that the methods and apparatus described herein are illustrative only and do not limit the scope of the claims.

Claims

1. A propulsion system, comprising: at least one conduit configured to carry and distribute motive fluid, the conduit further configured to contract when motive fluid is not supplied from the compressor and to expand when motive fluid is supplied from the compressor; as well as At least one ejector is in fluid communication with the at least one duct, wherein the compressor supplies compressed air to the at least one ejector to generate thrust, and wherein the at least one ejector is retractable into the volume of the wing when not in use, thereby streamlining the exterior of the wing.

2. The propulsion system according to claim 1, wherein: The wing is a component of at least one of a vertical take-off and landing aircraft, a short take-off and landing aircraft, or a conventional take-off and landing aircraft.

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