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CN-121630604-B - Miniature solid rocket nozzle structure and miniature solid rocket engine

CN121630604BCN 121630604 BCN121630604 BCN 121630604BCN-121630604-B

Abstract

The invention belongs to the technical field of solid rocket engines, and particularly discloses a miniature solid rocket nozzle structure and a miniature solid rocket engine, wherein the nozzle structure comprises a nozzle shell, a heat insulation layer is arranged on the inner wall of the nozzle shell, and a throat liner is arranged on the inner wall of the heat insulation layer; the throat lining comprises a convergence section, a straight section and an expansion section, the convergence half angle of the convergence section is 15-30 degrees, the thickness of the throat lining is 0.5-1.0 mm, and the throat lining is conformal with the heat insulation layer. The throat liner comprises the convergence section, the straight section and the expansion section which are integrally formed, so that gaps and discontinuous points of thermal resistance possibly existing in the traditional sectional type or spliced throat liner are eliminated, the smoothness of a heat conduction path is ensured, the whole throat region can uniformly and rapidly reach a required high-temperature state, and the generation of solid sediment is reduced from the source.

Inventors

  • HUANG WEIBO
  • ZHANG FEI

Assignees

  • 陕西普利美材料科技有限公司

Dates

Publication Date
20260512
Application Date
20260202

Claims (7)

  1. 1. The miniature solid rocket nozzle structure is characterized by comprising a nozzle shell (3), wherein an insulating layer (2) is arranged on the inner wall of the nozzle shell (3), and a throat liner (1) is arranged on the inner wall of the insulating layer (2); The throat liner (1) comprises a convergence section, a straight section and an expansion section, wherein the convergence section, the straight section and the expansion section of the throat liner (1) are integrally formed, and the convergence half angle of the convergence section is 15-30 degrees; the thickness of the throat liner (1) is 0.5-1.0 mm, and the throat liner (1) is conformal with the heat insulation layer (2); the throat liner (1) is formed by plasma spraying on the heat insulation layer (2) in an integrated manner; the throat liner (1) comprises a supporting lining layer, a gradient lining layer and a working lining layer which are integrally sprayed from inside to outside; the support lining layer is ceramic powder which is sprayed on the heat insulation layer in a plasma mode; The gradient lining layer is mixed powder of ceramic powder and metal powder which are sprayed on the supporting lining layer in a plasma mode, and the metal powder content of one side, far away from the supporting lining layer, of the gradient layer is higher than that of the ceramic powder; the working lining layer is metal powder which is sprayed on the gradient lining layer in a plasma mode.
  2. 2. A miniature solid rocket nozzle structure according to claim 1, wherein said insulating layer (2) is molded from high silica or carbon phenolic and is bonded inside said nozzle housing (3).
  3. 3. A micro solid rocket nozzle structure according to claim 2, wherein the ceramic powder is at least one of zirconium carbide, silicon carbide, zirconium oxide, zirconium boride; the metal powder is at least one of molybdenum powder, molybdenum alloy powder, tungsten powder and tungsten alloy powder.
  4. 4. A micro solid rocket nozzle structure according to claim 3, wherein the inner surface of the throat liner (1) is provided with a swirl groove (4) so that the swirling flow is generated when the fuel gas flows through the converging section, and the swirl groove (4) extends from the converging section to the straight section.
  5. 5. A micro solid rocket nozzle structure according to claim 4, wherein the inner surface of the throat liner (1) and the inner surface of the swirl groove (4) are subjected to polishing mirror surface treatment.
  6. 6. The miniature solid rocket nozzle structure according to claim 5, wherein the pitch of the cyclone groove (4) is 0.5-1.5 times of the inner diameter of the inlet of the throat liner converging section, the helix angle is 10-25 degrees, the depth of the cyclone groove (4) is 0.1-0.3 mm, and the width of the cyclone groove is 0.2-0.5 mm.
  7. 7. A miniature solid rocket engine comprising the miniature solid rocket nozzle structure of any one of claims 1-6.

Description

Miniature solid rocket nozzle structure and miniature solid rocket engine Technical Field The invention belongs to the technical field of solid rocket engines, and particularly relates to a miniature solid rocket nozzle structure and a miniature solid rocket engine. Background When the miniature solid rocket engine is practically applied, the working thrust of the engine is smaller due to the small whole bullet mass, so that the throat diameter of the spray pipe is less than phi 3.5 mm. The propellant generally adopts a propellant formula containing aluminum powder, when metal oxides such as aluminum oxide generated by a combustion chamber pass through a throat diameter, liquid metal oxides can be deposited due to the fact that the initial temperature of the throat liner is below 60 ℃, the size of the throat liner can be reduced to be below 2.0mm, the working pressure of an engine is seriously beyond the design maximum pressure, and an engine shell is disassembled and the task is failed when the working pressure is seriously increased. The problem of aluminum powder deposition at the throat liner can be solved by adopting a propellant without aluminum powder generally, but the problems are that 1. The conventional double-base propellant has low energy density, can increase the structural size and weight of an engine, and does not meet the design weight limit requirement of the engine. 2. The high-energy composite propellant has high price and low density, and can exceed the limit design index requirement of the low-cost engine. Disclosure of Invention The invention aims to overcome the defects in the prior art and provides a miniature solid rocket nozzle structure. In a first aspect of the invention, a miniature solid rocket nozzle structure is provided, comprising a nozzle housing, wherein an inner wall of the nozzle housing is provided with a heat insulation layer, and a throat liner is arranged on the inner wall of the heat insulation layer; the throat liner comprises a convergence section, a straight section and an expansion section, wherein the convergence half angle of the convergence section is 15-30 degrees; the thickness of the throat lining is 0.5-1.0 mm, and the throat lining is conformal with the heat insulation layer. In a further scheme, the heat insulation layer is made by high silica or carbon phenolic aldehyde mould pressing and is adhered to the inside of the spray pipe shell. Further, the convergent section, the straight section and the divergent section of the laryngeal mask are integrally formed. The further proposal is that the throat lining is formed on the heat insulation layer by plasma spraying. The throat lining comprises a supporting lining layer, a gradient lining layer and a working lining layer which are integrally sprayed from inside to outside; the support lining layer is ceramic powder which is sprayed on the heat insulation layer in a plasma mode; The gradient lining layer is mixed powder of ceramic powder and metal powder which are sprayed on the supporting lining layer in a plasma mode, and the metal powder content of one side, far away from the supporting lining layer, of the gradient layer is higher than that of the ceramic powder; the working lining layer is metal powder which is sprayed on the gradient lining layer in a plasma mode. The ceramic powder is at least one of zirconium carbide, silicon carbide, zirconia and zirconium boride; the metal powder is at least one of molybdenum powder, molybdenum alloy powder, tungsten powder and tungsten alloy powder. According to a further scheme, the inner surface of the throat liner is provided with a swirl groove, so that swirl is generated when fuel gas flows through the converging section, and the swirl groove extends from the converging section to the straight section. Further, the inner surface of the throat liner and the inner surface of the swirl groove are polished and mirror-finished. The spiral flow groove has a pitch which is 0.5-1.5 times of the inner diameter of the inlet of the throat lining convergence section, a helix angle of 10-25 degrees, a depth of 0.1-0.3 mm and a width of 0.2-0.5 mm. In a second aspect of the invention, a miniature solid rocket motor is provided, the motor comprising the miniature solid rocket nozzle structure described above. Compared with the prior art, the invention has the beneficial effects that: The throat liner comprises the convergence section, the straight section and the expansion section which are of an integral structure, so that gaps and discontinuous points of thermal resistance possibly existing in the traditional sectional type or spliced throat liner are eliminated, the smoothness of a heat conduction path is ensured, the whole throat region can uniformly and rapidly reach a required high-temperature state, and the generation of solid sediment is reduced from the source. The throat liner adopts a thin-wall structure of high heat conduction material, so that the temperatu