RU2468235C1 - Intermittent-cycle air-jet engine (icaje) - Google Patents

Abstract

FIELD: engines and pumps.

SUBSTANCE: invention refers to the equipment and mainly to military equipment, i.e. to airborne vehicle engines, and can be used preferably as the engine of small unpiloted aircrafts such as unpiloted scout aircrafts, flying targets, etc., as well as additional drop engines. Intermittent-cycle air-jet engine includes namely combustion chamber, resonator pipe, inlet pipes, gas supply nozzle, gas heating coil and ignition plug. Inlet pipes are of segmented annular section. Rear end wall of combustion chamber is provided with a shield above the inlet of resonator pipe that is located with eccentricity relative to combustion chamber axis.

EFFECT: increasing thermodynamic efficiency by increasing pressure pulsation amplitude.

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Description

The invention relates to equipment, mainly military, in particular to aircraft engines, and can most likely be used as the engine of small unmanned aerial vehicles, such as unmanned reconnaissance vehicles, flying targets, etc., as well as additional discharged engines.

Known pulsating air-jet engine (hereinafter PuVRD) of the German cruise missile of World War II V-1 (see G. B. Sinyarev, M. Dobrovolsky. Liquid rocket engines. - Oborongiz, 1957, p.19, 20) . It is a channel of circular cross section open at both ends, including an inlet diffuser, a valve grill, a combustion chamber and an output device consisting of a confuser and an exhaust pipe, as well as a fuel supply system and an ignition system with an electric igniter installed in the combustion chamber. In the General case, the input and output devices PuVRD may have a form different from the prototype, so in the future we will call them accepted terms air intake and nozzle.

The valve grille is a structure of supporting elements — transverse rods, movable elements — flat elastic plates of constant thickness, attached to the side faces of the rods in pairs parallel to each other at a distance equal to the thickness of the rod, and support spacers placed in the middle between the pairs of plates parallel to them. In each pair between the plates there is a blind gap facing back. The plates and spacers form longitudinal channels for the passage of air.

The flow incident on the PuVRD passes through the air intake and valve grille into the combustion chamber. Volatile fuel is supplied there, after which the air-fuel mixture is ignited by an electric spark. Quickly expanding in all directions, the combustion products, falling into a dead gap between the plates, are inhibited, as a result of which the pressure there increases. This causes the plates to bend to the sides before contact with the support spacers or side walls. The air channels of the valve grille are blocked. The combustion products expire through the nozzle into the atmosphere, and their pressure on the closed valve grill creates an impulse of traction PuVRD.

After the pressure drop, the valve plate plates under the action of their elasticity, as well as the vacuum created in the chamber by the inertia of the outgoing gases, return to their original position. The next portion of air enters the chamber and the cycle repeats.

The valve grill serves as the main, but not the only element of the assembly that creates the PuVRD thrust and also includes side walls, fasteners, etc. In addition, other devices can perform the thrust creation function in such PuVRD. Therefore, in the future we will use the general term "traction unit" (as part of the PuVRD) and the specific one - the valve grille of the traction unit.

The advantages of PuVRD with mechanical valve grids are simplicity and low cost, low weight, reliability. Their disadvantage is poor traction characteristics, namely low specific and frontal thrust, high specific fuel consumption, impulse nature of thrust, but most importantly - low valve life.

Also known design PuVRD using aerodynamic valves, "Unsteady flame propagation", ed. J.G. Markstein, M., MIR, 1968, pp. 40-40. In addition, PuVRD, in which the replacement of mechanical valves by aerodynamic, described in US patent No. 2796735, 1957; No. 2796734, 1957; No. 2746529, 1956; No. 2822037, 1958; 2812635, 1957; 3093962, 1963.

The disadvantages of such high pressure air exhaust systems are the low amplitude of pressure pulsations and, accordingly, the low thermodynamic efficiency (efficiency).

It is possible to increase the specific and frontal thrusts and reduce specific fuel consumption by increasing the amplitude of pressure pulsations, which is achieved by increasing the rate of combustion of the air-fuel mixture in the combustion chamber of the air-propulsion system. An increase in the amplitude of pulsations leads to an increase in thermodynamic efficiency and, accordingly, to a decrease in specific fuel consumption.

The technical result of the invention is to increase the thermodynamic efficiency by increasing the amplitude of pressure pulsations by creating more favorable conditions for the occurrence of detonation.

The stated technical problem is solved by intensifying the mass transfer process in the combustion chamber and in the zone of location of the heated gas coil in the initial part of the resonator pipe, achieved by organizing an intensive flow of the air-fuel mixture around the perimeter of the wall zone of the combustion chamber and the resonator pipe. And this leads to an increase in the rate of quasi-detonation combustion up to detonation. At the same time, “quasi-teston” burning means burning with increased speeds of advancement of the flame front, which in the case of an air-propelled rocket engine is 100 m / s or more. And with detonation - 1000 m / s or more. The organization of such a combustion regime occurs due to the intense mass transfer in the combustion chamber and on the coils of the heated gas coil, which acts as a turbulator. The speed of the flame front is proportional to the speed of mass transfer.

The specified technical result in the implementation of the invention is achieved by the fact that in the well-known air exhaust system, which contains, in particular, a combustion chamber, a resonator tube, inlet pipes, a gas supply nozzle, a gas heating coil and a spark plug, the PuVRD intake pipe is made in a segmented circular section, and the rear the end wall of the combustion chamber is made with a visor above the entrance to the resonator tube, which is located with an eccentricity relative to the axis of the combustion chamber.

Comparison of scientific, technical and patent documentation on the priority date in the main and related sections of the MKI shows that the set of essential features of the claimed solution was not previously known, therefore, it meets the patentability condition of “novelty”.

The analysis of known technical solutions in the art showed that the proposed device has features that are not available in the known technical solutions, and their use in the claimed combination of features makes it possible to obtain a new technical result, therefore, the proposed technical solution has an inventive step compared to the existing level technicians.

The proposed technical solution is industrially applicable, because can be manufactured industrially, efficiently, feasibly and reproducibly, therefore, meets the patentability condition "industrial applicability".

Other features and advantages of the claimed invention will become apparent from the following detailed description, given solely in the form of a non-limiting example and with reference to the accompanying drawings, illustrating a preferred embodiment, which shows:

Figure 1 - diagram of the proposed PuVRD;

Figure 2 is a cross section of the diagram of figure 1 by plane AA;

Figure 3 is a cross-section of the circuit of figure 1 by the plane BB;

Figure 4 is a cross-section of the circuit of figure 1 plane CC;

The positions in the drawing show:

1 - gas supply nozzle,

2 - the first inlet pipe is a mixer,

3 - inlet pipe

4 - combustion chamber,

5 - visor,

6 - rear end wall of the combustion chamber,

7 - resonator tube,

8 - glow plug

9 - gas heating coil,

10 - throttle,

11 - fuel tank (with liquid propane),

12 - gas line,

13 - zone of impact of the air-gas mixture on the rear end wall of the combustion chamber 6,

arrow 14 is the annular flow of the air-gas mixture.

PuVRD, shown in the drawing, contains a nozzle 1 for supplying gas with coaxially fixed first inlet pipe - mixer 2 and inlet pipe 3 PuVRD. A combustion chamber 4 with a rear end wall 6 and a visor 5 is fixed to the end of the inlet pipe 3 of the PuVRD 5. A resonator pipe 7 with a glow plug 8 is fixed to the rear end wall 6 of the combustion chamber 4. The gas heating coil 9 is connected to the fuel tank 11 through the throttle 10, which contains liquid propane, and through the gas line 12 - with a gas supply nozzle 1.

When the inductor 10 is partially opened and a spark is supplied to the spark plug 8, the gas ignites and burns inside the combustion chamber 4. After some time, the gas heating coil 9 and the walls of the combustion chamber 4 are heated and the further opening of the inductor 10 leads to the implementation of the operation cycle of the air-exhaust gas turbine engine. It is carried out as follows. The gas supplied through the gas supply nozzle 1 ejects air into the first inlet pipe — mixer 2 and PuVRD inlet pipe 3. Next, the jet stream of the air-gas mixture strikes the rear end wall 6 of the combustion chamber 4. The impact zone is shown in FIG. 4 by 13. impact on the rear end wall 6, the jet spreads along the rear end wall 6. An increase in the mass fraction of the air-gas mixture entering the lower part of the combustion chamber 4 is achieved by limiting the direct flow of the air-gas mixture into the resonator tubes 7 visor 5. The thus formed within shown in Figure 4 at 14. It uniformly over the entire length of the resonator pipe circumference 7 enters into it and flowing onto the gas heating coil windings 9 becomes turbulent as a "Spiral Shchelkin". In this case, the combustion process is accelerated inside the combustion chamber 4 up to detonation, which increases the thermodynamic efficiency of the PuVRD.

The described process corresponds to one operational cycle of the PuVRD. Cycling of work is traditionally realized by tuning to resonance, due to a change in the length of the first inlet pipe — mixer 2, the length of the resonator pipe 7 and the geometry of the combustion chamber 4 with the inlet pipe PuVRD 3.

Of course, the invention is not limited to the described example of its implementation, shown in the accompanying drawings. It remains possible to change various elements or replace them with technically equivalent, not beyond the scope of the present invention

Claims (1)

A pulsating jet engine (PUVRD), comprising, in particular, a combustion chamber, a resonator pipe, inlet pipes, a gas supply nozzle, a gas heating coil and a spark plug, characterized in that the inlet pipes are made in a segmented circular section and the rear end wall the combustion chamber is made with a visor above the entrance to the resonator tube, which is located with an eccentricity relative to the axis of the combustion chamber.

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