RU2749083C1 - Two-circuit ejector pulsating air-jet engine - Google Patents

Abstract

FIELD: military equipment.SUBSTANCE: invention relates to equipment, mainly to military equipment, namely to aircraft engines, and can be used, most likely, as an engine of small unmanned aerial vehicles, such as anti-aircraft, aviation and tactical missiles, unmanned reconnaissance aircraft, flying targets, etc. A two-circuit ejector pulsating air-jet engine (TEPuAJE) has a combustion chamber, a resonator tube, the first inlet mixing tube, in which an aerodynamic valve is installed, the second inlet mixing tube, a gas supply nozzle, a gas heating coil and a spark plug. The first inlet mixing tube is located inside the pipe of the combined air duct, hermetically fixed on the second inlet mixing tube adjacent to the end, which, in turn, is fixed on the front end wall of the combustion chamber. While a petal mechanical valve is installed inside the combined air duct at the entrance to the second inlet mixing tube.EFFECT: increased thermodynamic efficiency is achieved by reducing unproductive fuel consumption.1 cl, 3 dwg

Description

The invention relates to technology, mainly military, namely to aircraft engines, and can be used, most likely, as an engine of small unmanned aerial vehicles, such as, for example, unmanned reconnaissance aircraft, flying targets.

Known pulsating jet engine (hereinafter PuVRD) German cruise missile during the Second World War V-1 (see GB Sinyarev, MV Dobrovolsky. Liquid rocket engines. - Oborongiz, 1957, pp. 19, 20) ... It is a channel with a circular cross-section open at both ends, which includes a sequentially located inlet diffuser, a valve grate, a combustion chamber and an outlet 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 of the PUVRD can have a shape different from the prototype, therefore, in what follows, we will call them by the accepted terms - air intake and nozzle.

The valve lattice is a structure of load-bearing elements - transverse rods, movable elements - flat elastic plates of constant thickness, attached to the lateral faces of the rods in pairs parallel to each other at a distance equal to the rod thickness, and support spacers placed in the middle between the pairs of plates parallel to them. Each pair has a blind gap facing backwards between the plates. The plates and spacers form longitudinal air ducts.

The flow on the engine passes through the air intake and the valve grate into the combustion chamber. Volatile fuel is supplied there, after which the air-fuel mixture is ignited by an electric igniter spark. Combustion products rapidly expanding in all directions, falling into the blind gap between the plates, are inhibited, as a result of which the pressure there increases. This causes the plates to bend laterally until they contact the support spacers or side walls. The air channels of the valve grate are blocked. The combustion products flow out through the nozzle into the atmosphere, and their pressure on the closed valve lattice creates a thrust impulse of the engine.

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

The advantages of PUVRD with mechanical valve grids are simplicity and low cost, low weight, reliability and high hydraulic resistance to combustion products trying to break through against the incoming flow during an explosion in the combustion chamber.

Their disadvantage is a high hydraulic resistance when blowing out the combustion chamber, which leads to a low cyclic volumetric filling and, as a consequence, to a low specific and frontal thrust. But the main thing is that they give a drop in thrust at high flight speeds due to mechanical bending by the dynamic air pressure of the valve blades, which leads to a transition to the operation mode of the ramjet VRM.

Also known are the design of PUVRD using aerodynamic valves, "Pulsating air-jet engines", ed. K.V. Migalina, - Togliatti: TSU Publishing House, 2014, p. 81. In addition, PuVRD, in which the replacement of mechanical valves with aerodynamic ones, is described in US patents No. 2796735, 1957; No. 2796734, 1957; No. 2746529, 1956; No. 2822037, 1958; 2812635, 1957; 3093962, 1963.

The disadvantages of such PUVRDs include a low amplitude of pressure pulsations and, accordingly, a low thermodynamic efficiency (efficiency) caused by significant losses of fuel emitted from the intake system.

In the patent for invention RU 2714463 SPK F02K 7/067 (2019.08), published on February 17, 2020, BI No. 5, a device for a forced by-pass ejector pulsating jet engine (DEPuVRD) is presented, containing, in particular, a combustion chamber, an intake system from the first and second mixers, aerodynamic valves, fuel manifold and fuel nozzle. At the entrance to the second mixer of the considered DEPuVRD, an annular shell with a length of 0.3-0.5 caliber of the second mixer is installed, and the resonator tube is made with perforation with profiled holes in the area adjacent to the combustion chamber and partial diffuser opening located in the aerodynamic shadow behind the combustion chamber, when A triangular channel with a length of 0.1 to 0.5 of the length of the first mixer is installed inside the inlet section of the first mixer. Both air valves are aerodynamic.

As the closest analogue (prototype), the device of a forced by-pass ejector pulsating air-jet engine protected by a patent for invention RU 2717479, SPK F02K 7/067 (2020.01), published 03/23/2020, BI No. 9, is considered. Forced by-pass ejector pulsating air-jet engine (DEPuVRD) containing, in particular, a combustion chamber, an intake system from the first and second mixers, aerodynamic valves, a fuel manifold and a fuel supply nozzle, a fuel heating coil and a resonator tube with partial diffuser opening. A distinctive feature of this DEPuVRD is that the rear wall of the combustion chamber is made with the first visor of the echelon with rectangular slots for the formation of flat jet flows behind them, inside the combustion chamber behind the first visor there is a perforated niche with a second visor protruding into the flow, and the fuel heating coil has an uneven in diameter and oblique along the axis of the winding.

In the closest analogue, through its constructive refinement, there are possibilities to increase the thermodynamic efficiency (efficiency) and, accordingly, reduce the specific fuel consumption.

The technical result achieved as a result of the implementation of the proposed invention is to increase the thermodynamic efficiency by increasing the reverse hydraulic resistance of the intake system.

The technical problem is solved by increasing the specific and frontal thrust of the DEPuVRD with a corresponding decrease in fuel consumption in the purge mode by preventing the release of the air-fuel mixture into the atmosphere during an explosion in the combustion chamber.

The specified technical result, in the implementation of the invention, is achieved by the fact that in the known DEPuVRD containing a combustion chamber, a resonator pipe, the first inlet pipe - a mixer in which an aerodynamic valve is installed, a second inlet pipe - a mixer, a gas supply nozzle, a gas heating coil and a glow plug , the first inlet pipe - the mixer is located inside the pipe of the combined air duct, hermetically fixed at the inlet to the second inlet mixer pipe, which, in turn, is fixed on the front end wall of the combustion chamber, while, inside the combined air duct, at the entrance to the second inlet pipe - mixer, a petal mechanical valve is installed.

With such a design, an increase in the specific and frontal thrust and a decrease in the specific fuel consumption of the DEPuVRD during the purge cycle are achieved, due to an increase in the return hydraulic resistance of the intake system in the area of formation of a gap between the intake pipes - mixers when installing a mechanical petal valve. Reducing fuel losses when ejected from the intake system leads to an increase in thermodynamic efficiency and, accordingly, to a decrease in specific fuel consumption.

Comparison of scientific, technical and patent documentation as of the priority date in the main and adjacent headings of the ICI shows that the set of essential features of the claimed solution was not previously known, therefore, it meets the "novelty" condition of patentability.

Analysis of the known technical solutions in this field of technology showed that the proposed device has features that are absent in the known technical solutions, and their use in the claimed set of features makes it possible to obtain a new technical result, therefore, the proposed technical solution has an inventive step in comparison with the existing level technology.

The proposed technical solution is industrially applicable, since can be industrially manufactured, operable, feasible and reproducible, and therefore meets the "industrial applicability" requirement of patentability.

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.

FIG. 1 shows the inventive double-circuit ejector PuVRD.

FIG. 2 shows the closed state of a lobe mechanical valve at the moment of explosion in the combustion chamber.

FIG. 3 shows the open state of the lobe mechanical valve at the moment of purging.

The positions in the drawing show:

1 - gas supply nozzle,

2 - the first inlet mixer pipe,

3 - aerodynamic valve of the first inlet mixer pipe,

4 - a pipe of the combined air duct,

5 - petal mechanical valve of the combined air duct,

6 - the second inlet mixer pipe,

7 - combustion chamber,

8 - rear end wall of the combustion chamber,

9 - resonator tube,

10 - glow plug,

11 - diffuser bell of the resonator tube,

12 - fuel heating coil,

13 - aerodynamic valve,

14 - a tube of fuel supply to the aerodynamic valve,

15 - fuel manifold,

16 - the gap formed when the petal mechanical valve 5 is opened.

The double-circuit ejector PUVRD shown in the drawings contains a gas supply nozzle 1 with coaxially fixed first inlet mixer pipe 2, with an aerodynamic valve 3 fixed inside the pipe of the combined air duct 4, which in turn is rigidly fixed to the adjacent end of the second inlet mixer pipe 6 on the inlet into which, inside the combined air duct 4, a petal mechanical valve is installed 5. The second inlet mixer pipe 6 is attached to the combustion chamber 7 with a rear end wall 8. To the rear end wall 8 of the combustion chamber 7, a resonator pipe 9 with a spark plug 10 is fixed. 9 is performed with a diffuser bell 11. Inside the resonator tube 9 there is a fuel heating coil 12 through the fuel manifold 15 connected to the gas supply nozzle 1. A fuel supply pipe 14 is connected to the fuel manifold 15 through which fuel is supplied to the aerodynamic valve 13 fixed on the front wall of the chamber burn up i am 7.

The work of the proposed double-circuit ejector PuVRD is carried out as follows. At the blowing cycle of the double-circuit ejector PUVRD, when a vacuum is created in the combustion chamber 7, the gas supplied through the gas supply nozzle 1 ejects air into the first air intake circuit - into the first inlet mixer pipe 2 and the second inlet mixer pipe 6. At this moment, the vacuum in the chamber combustion 7 opens a mechanical lobe valve 5, FIG. 3, and the air from the combined air duct 4 through the slot 16 between the inlet mixer pipes 2 and 6 enters the combustion chamber 7. Further, the jet flow of the air-gas mixture, reaching the rear end wall 8 of the combustion chamber 7, collides with it, where it occurs combustion initialization. Combustion products then move from the combustion chamber 7 into the resonator tube 9. The initiated explosion of the fuel-air mixture leads to a sharp increase in pressure in the combustion chamber 7 and the subsequent emission of combustion products in the direction of the resonator tube 9 and inlet mixer pipes 2 and 6. In this case, an increase in pressure leads to to the closure of the petal mechanical valve 5, see FIG. 2. This prevents gas containing a high content of fuel vapors from escaping from the gap 16 between the mixing pipes 2 and 6.

The described process corresponds to the phases of purging and ignition followed by combustion. Then the purge phase begins again and the cycle repeats. Cyclic operation is traditionally realized by tuning to resonance, by changing the length of the inlet mixer pipe 2, the length of the resonator pipe 9 and the geometry of the combustion chamber 7 with the second inlet mixer pipe 6.

The implementation of this constructive solution will allow to reduce fuel consumption by 25-30% and thereby increase the specific indicators of a two-circuit ejector PUVRD

Of course, the invention is not limited to the described embodiment shown in the accompanying figure. It remains possible to change the various elements or replace them with technically equivalent, without going beyond the scope of the present invention.

Claims (1)

A two-circuit ejector PUVRD containing a combustion chamber, a resonator tube, a first inlet mixer tube in which an aerodynamic valve is installed, a second inlet mixer tube, a gas supply nozzle, a gas heating coil and a spark plug, characterized in that the first inlet mixer tube is located inside the pipe of the combined air duct, hermetically fixed on the adjacent end of the second inlet mixer pipe, which, in turn, is fixed on the front end wall of the combustion chamber, while inside the combined air duct, at the entrance to the second inlet mixer pipe, a petal mechanical valve.

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