Pulse drive

Abstract

A device serves for the repeated generation of explosions, in particular for the drive of an aircraft. It comprises: .square-solid.a combustion chamber (21), .square-solid.at least one feed line for feeding a flowable, explosive material or components which form an explosive material upon mixing to the combustion chamber (21); .square-solid.a discharge device for the targeted discharge of a gas pressure which is generated by way of ignition of the explosive material in the combustion chamber (21), .square-solid.a movable nozzle regulating element (26) for the partial or complete closure of the discharge device, .square-solid.an actuating element (25) which is configured to open the discharge device further after opening of the discharge device and during an outflow of explosion gases by way of the discharge device. Here, the discharge device has a plurality of part nozzles (40) for the discharge of the gas pressure, and a position of the part nozzles (40) can be set by way of the actuating element (25).

Claims

1-15. (canceled)

16. A device for the repeated generation of explosions and for converting chemical energy into kinetic energy of outflowing exhaust gases of the explosions, in particular for generating thrust for the propulsion of an aircraft, comprising: a combustion chamber (21), at least one feed conduit for feeding a flowable, explosive material or of components which on mixing form an explosive material, to the combustion chamber (21); a discharge device for the directed discharge of a gas pressure which is produced in the combustion chamber (21) by the ignition of the explosive material, a movable nozzle regulation element (26) for the partial or complete closure of the discharge device; an actuating element (25) which is designed to open the discharge device further after an opening of the discharge device and during the outflow of explosion gases through the discharge device, characterised in that the discharge device comprises several part-nozzles (40) for discharging the gas pressure, and a position of the part-nozzles (40) is adjustable by the actuating element (25).

17. The device according to claim 16, wherein each of the part-nozzles (40) comprises a part valve seat (41) and a part valve body (42), and a part nozzle inlet area (43) is determined by the position of the part valve body (42) in relation to the part valve seat (41), and wherein the nozzle regulation element (26) determines the positions of the part valve bodies (42) in relation to the part valve seats (41).

18. The device according to claim 16, wherein openings of the part-nozzles (40) comprise annular openings which are arranged concentrically to one another.

19. The device according to claim 16, wherein the combustion chamber (21) has a changeable volume.

20. The device according to claim 19, comprising a displaceably arranged separating wall (28) which forms a delimitation of the combustion chamber (21).

21. The device according to claim 20, in which the separating wall (28) forms a delimitation of the combustion chamber (21) which lies opposite the discharge device, and in particular the actuating element (25) is led through the separating wall (28).

22. The device according to claim 16, comprising a compressing device (1, 2) for compressing the flowable explosive material or at least one of the components of the explosive material.

23. The device according to claim 22, wherein the compressing device is a continuously operated compressor (2), in particular a rotating compressor, for example a turbo-compressor.

24. The device according to claim 23, wherein the compressor (2) is driven by a turbine (4), and the turbine (4) is arranged to be driven by an exhaust gas jet (5) from a turbine combustion chamber (6), wherein the turbine combustion chamber (6) is different to the combustion chamber (21).

25. The device according to claim 23, wherein the compressor (2) is driven by a turbine (4), and the turbine (4) is arranged to be driven by exhaust gases (17) of the combustion chamber (21).

26. The device according to claim 25, comprising an output for delivering mechanical work to a mechanical consumer, in particular to at least one of: a flow machine, in particular a propeller, for the propulsion of a vehicle, in particular of an aircraft, and a generator for conversion into electrical energy.

27. The device according to claim 22, comprising a compression device in the form of an air inlet (1), for compressing inflowing air given supersonic speed of the device in relation to the ambient air.

28. A method for repeated generation of explosions and for converting chemical energy into kinetic energy of outflowing exhaust gases of the explosions, in particular for producing thrust for the propulsion of an aircraft, the method comprising the repeated execution of the following steps: feeding a flowable, explosive material or components which on mixing form the explosive material, into a combustion chamber (21), wherein a discharge device of the combustion chamber (21) is closed at least partly by way of a movable nozzle regulation element (26), and generating, in relation to an ambient pressure, an overpressure in the combustion chamber (21); opening the discharge device; igniting the explosive material in the combustion chamber (21); leading away explosion gases through the discharge device; and at least partial closure of the discharge device by way of the movable nozzle regulation element (26); characterised in that: for opening the discharge device and on leading away explosion gases, several part-nozzles (40) are opened synchronously to one another; and for the at least partial closure of the discharge device, several part-nozzles (40) are at least partly closed synchronously to one another.

29. The method according to claim 28, wherein the part-steps opening the discharge device, igniting the explosive material in the combustion chamber and leading away explosion gases through the discharge device by way of the movable nozzle regulation element are carried out in a temporally overlapping manner.

30. The method according to claim 28, wherein the part-nozzles (40) each comprise part valve seats (41) and part valve bodies (42), and the part valve bodies (42) are moved synchronously to one another in relation to the part valve seats (41) by way of the nozzle regulation element (26).

Description

[0068] The subject-matter of the invention is hereinafter explained in more detail by way of preferred embodiment examples which are represented in the accompanying drawings. Shown schematically are:

[0069] FIG. 1 a pulse drive machine or pulse engine (PE);

[0070] FIG. 2 an operating mode of the PE with the variable volume of its combustion chamber;

[0071] FIG. 3 an operating mode with a variable frequency;

[0072] FIG. 4 increase of an opening speed by way of the use of several part-nozzles with individual nozzle openings;

[0073] FIG. 5 different nozzle bodies each with several nozzle openings;

[0074] FIG. 6 a PE with a charging by way of a separate gas turbine;

[0075] FIG. 7 a PE with a charging by way of a turbine which is driven by exhaust gases of the PE;

[0076] FIG. 8 a PE with a propeller which is driven by the turbine; and

[0077] FIG. 9 a PE with a generator which is driven by the turbine.

[0078] Basically in the figures, the same or equally acting parts are provided with the same reference numerals.

[0079] FIG. 1 shows a device for the repeated generation of explosions, hereinafter also called pulse engine or PE 15. A combustion chamber 21 or explosion space can be filled with a flowable, explosive material, for example an explosive gas mixture, via a filling device. For this, the filling device comprises a combustion chamber air inlet 12 for the feed of an oxidant, for example air, and a combustion chamber combustible inlet 14 for the feed of a combustible or fuel, for example hydrogen. The flowable explosive material which is formed therefrom can be ignited and brought to explode by an ignition device, for example by a spark plug 23.

[0080] An outlet of the combustion chamber 21 for exhaust gases 17 leads through nozzle openings 27. The nozzle openings 27 are closable by way of nozzle regulation elements 26 of an actuating element 24. In a neutral position, the nozzle opening 27 is closed by the actuating element 25. The actuating element 25 is herein held in this position by way of a gas spring 24.

[0081] The nozzle regulation element 26 seals the combustion chamber 21 towards the nozzle openings 27 during the filling of the combustion chamber 21. By way of this, a preliminary pressure with an overpressure can be produced, with which overpressure in turn a greater explosion pressure can be produced.

[0082] An auxiliary combustion chamber 22 is likewise fillable with an explosive material via a further filling device with an auxiliary combustion chamber air inlet 11 and with an auxiliary combustion chamber combustible inlet 13. The actuating element 25 is movable counter to the pressure of the gas spring 24 by means of an explosion in the auxiliary combustion chamber 22 and the nozzle opening 27 can be opened by way of this.

[0083] On operation of the PE 15, the auxiliary combustion chamber 22 and the combustion chamber 21 can each be filled with the same explosive material. Basically, different materials or different mixtures can also be applied in both combustion chambers. Firstly, the explosive material is ignited in the auxiliary combustion chamber 22 by way of an assigned spark plug 23.

[0084] By way of this, the pressure in the auxiliary combustion chamber 22 increases and the actuating element 25 begins to move and hence begins to release the nozzle opening 27 of the combustion chamber 21. The explosive material is subsequently ignited in the combustion chamber 21, for example by a further spark plug 23.

[0085] The spark plugs 23 of the auxiliary combustion chamber 22 and of the combustion chamber 21 are therefore ignited shortly after one another. A delay between the two ignition points in time can be selected such that an exit speed of the exhaust gases 17 or a total energy which is converted into kinetic energy of the exhaust gases 17 is maximised.

[0086] In another embodiment, the material in the combustion chamber 21, via a conduit or delay conduit, likewise filled with explosive material, is ignited by way of an explosion which comes from an auxiliary combustion chamber 22 and is led through the delay conduit.

[0087] The filling of the combustion chambers (combustion chamber 21 and auxiliary combustion chamber 22) can be effected in stages and in the following sequence, firstly the oxidant through the combustion chamber air inlet 12 or the auxiliary combustion chamber air inlet 11, then the combustible through the combustion chamber combustible inlet 14 or the auxiliary combustion chamber combustible inlet 3. Herewith, the respective combustion chamber wall can be cooled with the oxidant during the filling, without a mixture being able to ignite on the combustion chamber wall. The cooling possibility which is created on account of this permits the maximisation of the cycle frequency. Herewith, the power density, thus the maximal thrust per combustion chamber volume can be maximised.

[0088] Regarding further elements of the design and method aspects for the operation of the device, the initially mentioned EP 3 146 270 A1 is referred to, whose contents are herewith incorporated into the present application.

[0089] The combustion chamber 21 comprises a separating wall 28 which forms a section of the entirety of the walls of the combustion chamber 21. The volume of the combustion chamber 21 is changeable by way of displacing the separating wall 28. The separating wall 28 can be displaced by way of a schematically represented adjusting device 281 and the volume can be varied herewith. In FIG. 1, the separating wall 28 by way of example is movable in the same direction, along which the actuating element 25 is moved to and fro.

[0090] FIG. 2 illustrates an operating mode of the PE 15 with a variable volume in its combustion chamber, each with a temporal course of a thrust F which is produced by the PE 15: in the upper course with a larger and in the lower course with a smaller volume of the combustion chamber, but with a constant pulse period tc. Given a reduced combustion chamber volume, the combusted mixture flows out more rapidly in comparison to the larger volume. The shortened outflow duration leads to the thrust prevailing for a shorter time duration. The average thrust of the PE 15 over time therefore reduces. The consumption of combustible and oxidiser per pulse as well as its temporal average also reduces due to the lower volume.

[0091] FIG. 3 shows an operating mode of the PE 15 with a variable frequency, in the upper course with a greater operating frequency (or smaller pulse period tc1) and in the lower course with a smaller operating frequency (or larger pulse period tc2). Herein, it is merely the number of thrust pulses per unit of time which is reduced, whilst the pulse per se is kept the same, i.e. with the same volume. By way of this, the thrust and the consumption in the temporal average also become smaller.

[0092] On operation, the volume as well as the operating frequency can be varied. Herewith, the same average thrust can be achieved with different combinations volumes and operating frequency, and the operation optimised. For example, the stoichiometry of the mixture can be varied herewith. For example, rapid load changes can be effected by way of adapting the operating frequency and subsequently given a constant load by way of the slow adaption of the volume given a simultaneously compensation by the operating frequency. Given an optimisation, one can take into account the fact that with a thrust regulation over the operating frequency, the individual pulses can all be of a certain optimised temporal course or pulse type. Concerning thermal losses, a large volume is more advantageous compared to a small volume with regard to the ratio of the surface to volume. Given a drive of an exhaust gas turbine, an additional degree of freedom is present with the selection of the operating state: depending on how the efficiency of the exhaust gas turbine behaves as a function of PE frequency and PE volume, it can be advantageous if the PE volume can be reduced in the part-load region.

[0093] FIG. 4 shows an increase of an opening speed by way of using several part-nozzles with individual nozzle openings. A nozzle with an individual nozzle opening 27 is shown on the left and a nozzle with several part-nozzles 40 is shown on the right. Each of the part-nozzles 40 comprises a part valve seat 41 and a part valve body 42. The part valve body 42 can bear on the part valve seat 41 and thus close the part-nozzle 40, and can be moved away from the part valve seat 41 for opening the part-nozzle 40. The part valve bodies 42 can be moved commonly, i.e. synchronously, by the actuating element 25, for example by way of the part valve bodies 42 being formed on the same body, or all being fastened to one another in a rigid manner on the actuating element 25 or on a common actuating device. On moving the part valve body 42 away from the part valve seats 41, given the same travel of the valve bodies or of the actuating element 25, a larger cross-sectional area is released than on using only one nozzle. Herewith, a temporal change of a total cross-sectional area of all part nozzles 40 is greater than on using only one single nozzle. Hence by way of the nozzle opening 27 consisting of several individual part-nozzles, the speed at which the nozzle opening 27 is opened and a larger cross-sectional area is released can be increased without the actuating element 25 having to be moved more rapidly.

[0094] The several part-nozzles 40 or the nozzle openings 27 can be shaped differently. FIG. 5 shows different nozzle bodies 30 each with several nozzle openings 27, arranged as concentric rings, radial linear jets and as circular openings with different diameters. In other embodiments, the circular openings all have the same diameter (not represented).

[0095] FIG. 6 shows a PE 15 with a charging by a separate gas turbine. Herein, fuel or combustible is transported from a combustible tank 7 via a fuel delivery device 18 and via fuel inlet valves (auxiliary combustion chamber combustible inlet 13 and combustion chamber combustible inlet 14) to the combustion chamber 21 and to the auxiliary combustion chamber 22 of the PE 15. A further fuel delivery device 18b delivers the fuel via a turbine combustion chamber feed valve 10 to a turbine combustion chamber 6 which is operated in a continuous (thus non-pulsating manner) and via a turbine 4 and shaft 3 drives a compressor 2. This compressor 2 is fed by air from an air inlet 1, compresses the air and leads it via the air inlet valves (auxiliary combustion chamber air inlet 11 and combustion chamber air inlet 12) into the combustion chambers 21, 22.

[0096] The compressor 2 can be a radial compressor or axial compressor as well be of one or more stages. The turbine 4 and the further turbine 4b can be one-stage or multi-stage. The air can already be pre-compressed in the air inlet 1 by way of ram pressure compressing. The higher the mach number of the inflowing air 16, the greater is this (pre) compressing. Since the air is already adequately compressed in the air inlet 1 given sufficiently high mach numbers, the compressor 2 becomes superfluous at these mach numbers. At mach numbers, at which the compressor 2 is required, a bypass valve 8 is closed and a compressor inlet valve 9 is open. If the compressor is no longer used due to the high speed of the inflowing air 16, then the compressor inlet valve 9 is closed and the bypass valve 8 is opened. By way of this, the compressor 2 is bridged. In this case a compressor outlet valve 19 is also closed.

[0097] A vehicle, in particular an aircraft can be propelled by the outflowing exhaust gases 17 of the PE 15 or by the thrust which is produced by way of this.

[0098] FIG. 7 shows a PE 15 with a charging by way of a further turbine 4b which is driven by exhaust gases 17 of the PE 15 via a common shaft 3. Instead of being driven by a separate gas turbine as an auxiliary assembly, the compressor 2 can also be driven via a turbine 4b which is driven by the exhaust gases 17 from the PE 15. In this case, one can forego the further fuel delivery device 18b as well as the turbine combustion chamber 6.

[0099] FIG. 8 shows a PE 15, in which the further turbine 4b which is driven by the exhaust gases 17 of the PE 15 drive a propeller or airscrew 201, in particular via a step-down gear 20. This propeller can be of a shrouded or a non-shrouded design. The propeller serves for the propulsion of a vehicle, in particular an aircraft, as with a turboprop. An exhaust gas jet 5 of the further turbine 4b can likewise contribute to the propulsion.

[0100] FIG. 9 shows a PE 15, in which the further turbine 4b which is driven by the exhaust gases 17 of the PE 15 drives a generator 202. When necessary, a step-down gear 20 can be arranged between the shaft 3 and the generator 202.