CN-116677513-B - Axisymmetric adjustable spray pipe adapting to characteristics of rotary detonation spiral shock wave

CN116677513BCN 116677513 BCN116677513 BCN 116677513BCN-116677513-B

Abstract

An axisymmetric adjustable spray pipe adapting to the characteristic of rotary detonation spiral shock waves relates to a rotary detonation engine. The device comprises a fixed section, an air storage chamber, a push rod, a connecting ring, a tractor, a contraction plate, an expansion inner plate, an expansion outer plate, a hooking piece and a thermoelectric conversion cover, wherein the fixed section is a framework which is formed by transition from a combustion chamber to a spray pipe, a hinge frame is arranged outside the fixed section and used for supporting the air storage chamber, the air storage chamber and the push rod are of a similar injector structure, the air storage chamber is hinged with the fixed section, the push rod is hinged with the connecting ring, one end of the tractor is hinged with the connecting ring, the other end of the tractor is hinged with the expansion outer plate and used for pulling the expansion outer plate to move, the expansion inner plate is hinged with the contraction plate, the thermoelectric conversion cover is a conical silicon-germanium alloy outer cover and used for absorbing waste heat of the spray pipe and converting the waste heat into electric energy, and energy is provided for the whole adjustable spray pipe. The relative airflow angle before shock wave can be controlled in a proper range under various working conditions in a wide speed range, so that the shock wave angle is controlled, and the oblique shock wave energy loss in the rotary detonation engine is reduced.

Inventors

HUANG YUE
XU ZHIWEI
LING WENHUI
ZHANG YINING
LI DONG
YOU YANCHENG

Assignees

厦门大学
北京动力机械研究所

Dates

Publication Date: 20260508
Application Date: 20230613

Claims (4)

1. The axisymmetric adjustable spray pipe adapting to the characteristics of rotary detonation spiral shock waves is characterized by comprising a fixed section, an air storage chamber, a push rod, a connecting ring, a tractor, a contraction plate, an expansion inner plate, an expansion outer plate, a hooking piece and a thermoelectric conversion cover; the fixed section is a framework which is formed by transiting a combustion chamber to the spray pipe, 4 air storage chambers are arranged outside the fixed section, 4 hinge frames are arranged outside the fixed section and used for supporting the air storage chambers, 24 shrinkage plates are arranged, 24 notches are formed inside the fixed section and used for supporting the shrinkage plates, and the shrinkage plates are limited to displace except the axial direction; the air storage chamber and the push rod adopt a similar injector structure, the change of the volume of air in the air storage chamber pushes the push rod to move back and forth, the air storage chamber is hinged with the fixed section, and the push rod is hinged with the connecting ring; the device comprises a connecting ring, a thermoelectric conversion cover, a conical silicon-germanium alloy outer cover, a telescopic expansion plate, a thermoelectric conversion cover and a heat-insulation plate, wherein the connecting ring is two semicircular rings, a hinge frame is arranged on the connecting ring and is used for being hinged with a push rod and the telescopic expansion plate; the expansion inner plate and the expansion outer plate are hinged and relatively rotate within an angle range of 30-60 degrees, and the expansion inner plate, the expansion inner plate and the expansion outer plate are metal plates with special molded surfaces, and the special molded surfaces are designed based on the characteristic that rotation knocking accompanies spiral shock waves so as to reduce the energy loss of the oblique shock waves.
2. The axisymmetric adjustable nozzle for accommodating characteristics of rotary detonation helical shock as claimed in claim 1, wherein a through hole is provided at a junction of said convergent plate and said divergent outer plate, and the convergent plate and the divergent outer plate are connected by an axis so as to be rotatable relative to each other.
3. The axisymmetric adjustable nozzle for adapting to the characteristics of rotary detonation helical shock of claim 1, wherein a hinging seat is arranged on the outer side of the expansion outer plate, and the expansion outer plate is hinged with the tractor through the hinging seat.
4. The axisymmetric adjustable nozzle for adapting to the characteristics of rotary detonation helical shock waves according to claim 1, wherein the air storage chamber is in the form of an outer cylinder of a syringe, the push rod is in the form of an inner core of the syringe, the air storage chamber is a high-efficiency water electrolysis device for generating electrolysis and reduction reaction of water in the air storage chamber, and the volume of air in a cavity is changed, so that the push rod is moved to realize the operation of the adjustable device.

Description

Axisymmetric adjustable spray pipe adapting to characteristics of rotary detonation spiral shock wave Technical Field The invention relates to a rotary detonation engine, in particular to an axisymmetric adjustable spray pipe adapting to the characteristics of rotary detonation spiral shock waves. Background Detonation waves are combustion waves that propagate at supersonic speeds and are violent and rapid in their form of combustion. The detonation wave is mainly generated by the induction of shock waves, and the structure of the detonation wave consists of a leading shock wave and a reaction area. The reaction zone is immediately followed by a leading shock wave zone, and the reactants are heated and combusted to release energy far exceeding that of ordinary combustion via compression of the leading shock wave. Compared with isobaric combustion, knocking combustion has the advantages of self-pressurization, high heat release rate and high heat cycle efficiency, and the complexity (Driscoll R,George A S,Gutmark E J.Numerical investigation of injection within an axisymmetric rotating detonation engine[J].International Journal of Hydrogen Energy,2016,41(3):2052-2063); of the system can be greatly reduced, so that the knocking engine becomes a popular research direction in the propulsion field. The silicon-germanium alloy is widely used as a thermoelectric material under the high-temperature condition, and has the main advantages of higher thermal stability, stronger oxidation resistance and high melting point (Cai Xingyu, wang Zan. The research status of the silicon-germanium thermoelectric material is [ J ]. Henan technology, 2019, no.670 (08): 140-141). And one end of the PN junction formed by connecting the semiconductor Seebeck effect, namely the P-type (hole) semiconductor and the N-type (electron) semiconductor is arranged near a heat source to form a hot end, and the other end of the PN junction is arranged near a cold source to form a cold end. The thermal excitation makes the concentration of holes and electrons at the hot end increase, the holes and electrons diffuse from the hot end to the cold end to form a potential difference, and a load is connected to generate current (Chen Y,Hou X N,Ma C Y,et al.Review of DevelopmentStatus of Bi2Te3-Based Semiconductor Themoelectric Power Gener-ation[J].Advances In Materials Science And Engineering,2018(5):150-169). The thermoelectric conversion hood is made of silicon germanium alloy, and can absorb waste heat of the spray pipe and convert the waste heat into electric energy under the action of the semiconductor Seebeck effect. The injector type air storage chamber is a high-efficiency water electrolysis device, electric energy converted from waste heat can be utilized, and the volume of gas in the cavity of the air storage chamber can be changed through the reduction reaction of electrolysis water and the oxidation reaction of hydrogen, so that power is provided for the whole adjustable device, energy consumption is reduced, and the high-efficiency work of the rotary detonation engine is realized. RDEs operating on rotary detonation (i.e., rotary detonation engines) have thrust from propagating detonation waves in an annular combustion chamber in a manner that is continuous in the circumferential direction. The energy losses of the RDE include mainly oblique laser energy losses, friction losses of gases, and blending losses of combustion tail gases into the atmosphere. The foremost of all energy losses is the oblique shock energy loss, so an effective way to save fuel is to reduce the oblique shock energy loss, which can greatly improve engine efficiency. The oblique shock wave energy loss mainly comprises two aspects, namely the energy loss generated when a flow field passes through a shock wave and the work applied to the flow field in the shock wave propagation process, wherein the shock wave angle and the shock wave intensity are main factors influencing the oblique shock wave energy loss, and the method adopted by the invention reduces the oblique shock wave energy loss by adjusting the shock wave angle. In the jet pipe, the shock wave angle and the relative air flow angle before shock wave (namely the relative angle between the air flow and the motion direction of the shock wave) show high positive correlation and show a certain causal relationship, so that the adjustment of the relative air flow angle before shock wave is a feasible way for adjusting the shock wave angle. The axial distribution condition of the Mach number and the propagation speed of the shock wave are the relative airflow angle determining factors before the shock wave, which guides the design of the spray pipe molded surface of the invention, namely firstly researching the optimal shock wave structure, calculating the Mach number distribution rule in the spray pipe corresponding to the optimal shock wave structure, and calculating the corresponding spray pipe molded surface. Disc