Liquid fueled pulse detonation engine with controller and inlet and exit valves

• US 5,901,550 A
• Filed: 03/18/1996
• Issued: 05/11/1999
• Est. Priority Date: 04/14/1993
• Status: Expired due to Fees

• Current Assignee: Shocksystem Incorporated
• Original Assignee: Adroit Systems, Inc. (General Dynamics Corporation)
• Inventors: Bussing, Thomas R. A., Bratkovich, Thomas E.
• Primary Examiner(s): Thorpe, Timothy S.
• Assistant Examiner(s): KIM, TAE JUN
• Application Number:
  US08/618,001
• Time in Patent Office: 1,149 Days
• Field of Search: 60/39.38, 60/39.39, 60/39.76, 60/39.78, 60/39.79, 60/39.8, 60/39.821, 60/39.826, 60/39.827, 431/1, 431/158, 431/278, 431/280
• US Class Current: 60/39.38
• CPC Class Codes: B01J 3/08 Application of shock waves for chemical reactions or for modifying the crystal structure of substances
• CPC Class Codes: B05B 7/0006 Spraying by means of explosions
• CPC Class Codes: C23C 4/126 Detonation spraying
• CPC Class Codes: F01D 5/288 Protective coatings for blades
• CPC Class Codes: F02K 7/06 with combustion chambers having valves
• CPC Class Codes: F02K 7/075 with multiple pulse-jet engines
• CPC Class Codes: F02K 9/972 Fluid cooling arrangements for nozzles F02K9/64 takes precedence
• CPC Class Codes: F02K 9/974 Nozzle- linings; Ablative coatings
• CPC Class Codes: F23R 7/00 Intermittent or explosive combustion chambers

Abstract

The invention provides a liquid fueled pulsed detonation air breathing engine. The engine has at least one, and preferably a multiplicity of, detonation chambers, each of which has an inlet end for opening and receiving a charge of fuel and air, and an outlet end for discharging combustion product gases. A fast-acting valve is located above the inlet ends of the detonation chambers and cyclically opens the fuel and air receiving openings in the inlet ends of the detonation chambers to allow a fuel/air charge to enter the chambers. In a preferred embodiment, the valve is of a rotary type with a body that has at least one opening through which fuel and air can flow into the inlet end of the detonation chamber. Once the valve has closed, detonation is initiated by an ignitor and impulse force is provided by the resultant shock wave. Thereafter, the valve opens again so that the detonation chamber can be charged with fuel and air to recommence the cycle. The invention also provides an embodiment of an engine that has both inlet and outlet valves. These valves operate out of phase so that when the inlet valve is open to receive fuel and air into the detonation chamber, the outlet valve is closed. When detonation commences, the outlet valve is open and the inlet valve is closed. Optionally, a source of oxygen allows a stratified charge in the engine to enhance detonation. Also provided is a control system (48) for sensing the position of the valves, (58, 80) and using this sensed position to inject fuel, inject oxygen and ignite the fuel and air mixture.

Claims

1. A liquid fueled pulse detonation engine comprising:

(a) at least two detonation chambers, each detonation chamber having an inlet end and an outlet end, the inlet end having an opening for receiving a detonable charge comprising a mixture of fuel and an oxidant, the chamber comprising a deflagration to detonation transition device along sidewalls of the inlet end of the chamber;

(b) an exit valve at the outlet end of each detonation chamber, the opening and closing of the exit valve out of phase with an inlet valve of said chamber;

(c) a reservoir of liquid fuel;

(d) a fuel injector in fluid communication with the fuel reservoir, the fuel injector supplying a controlled amount of fuel to each detonation chamber;

(e) a manifold for supplying air to each detonation chamber, the manifold in fluid communication with the inlet end of the chamber;

(f) an ignitor in each detonation chamber for initiating successive detonations of charges in the detonation chamber;

(g) an inlet valve for each detonation chamber enabling intermittent fluid communication between the manifold and the detonation chamber, the valve comprising a valve opening sized to cooperate with the opening for receiving a charge of the inlet end of the detonation chamber, so that when the engine operates, the valve opening allows fluid flow into said opening of the detonation chamber in the inlet end of said detonation chamber; and

(h) a controller receiving signals indicating positions of the inlet and exit valves and activating the fuel injector and the ignitor of each detonation chamber in response to the signals.

2. The engine of claim 1, wherein the inlet valve is a rotatable valve.

3. The engine of claim 2, further comprising a source of oxygen, and an oxygen injector able to inject oxygen from the source into the at least two detonation chambers.

4. The engine of claim 3, further comprising a source of oxygen, and an oxygen injector, wherein a controller activates the oxygen injector to inject oxygen into the at least two detonation chambers.

5. The engine of claim 1, wherein the fuel injector communicates with the detonation chamber through the inlet valve by infecting atomized liquid fuel through the valve opening into the inlet end of the detonation chamber.

6. The engine of claim 2, wherein the rotatable valve comprises a disk-shaped body.

7. The engine of claim 1, wherein the fuel injector is able to supply atomized liquid fuel, the atomized fuel comprising droplets with a Sauter mean diameter of less than about 40 microns.

8. The engine of claim 1, wherein the outlet end of each detonation chamber comprises an outwardly flaring nozzle.

9. The engine of claim 1, wherein the controller activates the fuel injector and ignitor of each detonation chamber in a predetermined cycle.

10. The engine of claim 9 wherein fuel injectors are located to inject fuel into the at least two detonation chambers through the inlet valve.

11. The engine of claim 9, wherein fuel injectors are located in the vicinity of inlet ends of the at least two detonation chambers to enable fuel injection directly into the inlet ends of said at least two detonation chambers, the injected fuel bypassing the inlet valve.

12. The engine of claim 1, wherein the inlet and outlet valves are rotatable valves.

13. The engine of claim 12, wherein the inlet and outlet valves are cone-shaped.

14. The engine of claim 12, wherein the inlet and outlet rotatable valves are coupled to a common drive motor for rotating the valves.

15. The engine of claim 1, further comprising a source of oxygen, and an oxygen injector able to inject oxygen into each detonation chamber.

16. The engine of claim 15, further comprising an oxygen supply controller, the controller activating and controlling the oxygen injector to supply a controlled amount of oxygen into the detonation chamber.

17. A liquid fueled pulse detonation engine, comprising:

(a) a detonation tube having an inlet end and an opposite outlet end, the inlet end having an opening for receiving a charge comprising a detonable mixture of fuel and an oxidant, the outlet end having an opening for discharging combustion product gases, the tube comprising a deflagration to detonation transition device extending along sidewalls of the inlet end of the tube;

(b) an inlet valve mounted to sequentially open and close the opening in the inlet end of the detonation tube;

(c) an outlet valve through which combustion products are expelled from the outlet end of the detonation tube;

(d) an air duct in intermittent fluid communication with the detonation tube through the inlet valve;

(e) a reservoir of liquid fuel mounted to the engine;

(f) a fuel delivery system in fluid communication with the reservoir for injecting controlled amounts of atomized liquid fuel into the inlet end of the detonation tube; and

(g) an ignitor near the inlet end of the detonation tube for igniting a fuel and air charge in the tube; and

(h) an ignitor controller receiving signals from a sensor for sensing positions of the inlet and outlet valves, the controller controlling the fuel delivery system and activating the ignitor in response to received signals from the sensor about valve positions.

18. The engine of claim 17, wherein the detonation tube is substantially cylindrical and the inlet and outlet ends are both tapered.

19. The engine of claim 17, wherein the inlet and outlet valves comprise rotatable valves, the valves each comprising valve bodies, each of the bodies having at least one opening therethrough.

20. The engine of claim 17, wherein fuel injection is by direct injection into an inlet end of the detonation tube, the injected fuel bypassing the inlet valve.

21. The engine of claim 17, further comprising an oxygen injection system comprising:

(a) a source of oxygen; and

(b) an oxygen control valve in fluid communication with the source of oxygen and the inlet end of the detonation tube, the oxygen control valve controlledly supplying oxygen into the inlet end of the detonation tube.

22. The engine of claim 17, comprising a plurality of detonation tubes.

23. The engine of claim 17, comprising four parallel substantially cylindrical detonation tubes arrayed at corners of a square.

24. The engine of claim 17, wherein the inlet and outlet valves each comprise a valve body, the valve bodies each cone-shaped with apexes of the bodies directed toward each other.

25. A method of producing a pulse detonation motive force in an air-breathing, liquid-fueled, engine comprising:

(a) charging an amount of liquid fuel and air into an inlet end of a detonation chamber while an opposite outlet end of the chamber is substantially closed, the amount of fuel controlled by a fuel injection system, the fuel injection system independent of an air supply metering system;

(b) forming, under computer control, a detonable fuel and air mixture in the detonation chamber;

(c) under computer control commencing opening an exit valve at the outlet end of the detonation chamber while commencing closing an inlet valve at the inlet end of the chamber, based on sensed signals indicating valve conditions at the outlet and inlet ends;

(d) utilizing internal structure at the inlet end of the detonation chamber to facilitate deflagration to detonation mode transfer;

(e) detonating the fuel and air mixture in the detonation chamber by activating an ignitor, under computer control, based on signals of inlet and outlet valve position transmitted to the computer;

(f) expelling combustion product gases from the detonation chamber;

(g) under computer control commencing opening the inlet valve of the detonation chamber while commencing closing the exit valve of the chamber; and

(h) repeating the cycles of steps (a) through (g).