Solid rocket engine throat liner assembly working for long time under high pressure and long exhaust nozzle

Abstract

The invention belongs to the technical field of solid rocket engines, and particularly provides a solid rocket engine throat liner assembly capable of working for a long time under high pressure intensity and a long exhaust nozzle, and the throat liner assembly is arranged at the head of the long exhaust nozzle and comprises a throat liner, a supporting ring, a backing and a heat insulation cap. The throat liner is arranged at the joint of the convergent section and the long tail section of the long tail nozzle shell, a supporting ring is arranged on the outer side of the throat liner, a backing is arranged on the outer side of the supporting ring, a heat insulation cap is arranged on the head portion of the throat liner, and the heat insulation cap covers the end portion of the throat liner, a butt joint seam between the throat liner and the supporting ring and a butt joint seam between the supporting ring and the backing. According to the solid rocket engine throat liner assembly and the long exhaust nozzle, it can be guaranteed that the long exhaust nozzle works reliably for a long time under high pressure, the structure and the inner molded surface of the nozzle are kept complete, the throat liner is not ablated, thrust loss is small, and the efficiency of the nozzle is high.

Description

Technical Field

[0001] The invention belongs to the technical field of solid rocket engines, and in particular, relates to a throat liner assembly and a long tail nozzle of a solid rocket engine working under high pressure and strength for a long time. Background Art

[0002] In the prior art, the throat liner of the long tail nozzle of the solid rocket engine is located at the tail of the long tail section, which results in a very long channel upstream of the throat liner, which will cause airflow obstruction. In addition, due to the limitation of the outer diameter of the long tail section, the axial support area that the long tail section can provide is limited, so it cannot withstand high pressure, and the average working pressure is 7MPa and below; the very long channel upstream of the throat will cause obstruction, and under the action of the high-pressure gas flow, the inner surface of the channel will be severely eroded and burned, and even cause nozzle fire.

[0003] For example, the comparative document CN105736184A discloses a throat structure of a large thrust ratio, long-time working micro-ablation throat liner and a diffuser section. The throat liner is located at the tail of the long tail section and is made of ablation-resistant metal material, made of W-Cu; the outer surface of the throat liner is bonded with a backing liner and a bottom liner, the backing liner is made of ablation-resistant non-metallic material, made of felt carbon / carbon material, and the backing liner is made of insulating non-metallic material, made of phenolic high-silica glass cloth board; the diffusion section insulation layer is made of felt carbon / carbon material; the throat liner, backing liner, bottom liner and diffusion section insulation layer are bonded together as a throat assembly, relying on the axial limit of the step at the tail of the long tail section shell, and its average working pressure is judged to be approximately 3MPa through the test curve.

[0004] For example, the long-term working solid rocket engine and its long tail nozzle in the comparative document CN115450798A, the throat liner is located at the tail of the long tail section, the material is tungsten infiltrated copper, and the front and rear carbon rings are used to wrap it, the material of the front carbon ring is piercing carbon-carbon composite material, and the material of the rear carbon ring is piercing carbon-carbon composite material; the backing has a backing mounting hole that runs through both ends, and the front carbon ring and the rear carbon ring carry the throat liner and insert and fix it into the backing mounting hole, and the material is high silicon oxygen / phenolic material; after the throat liner, the front carbon ring, the rear carbon ring and the backing are bonded into one, they are inserted and fixed to the tail section of the long tail nozzle shell, and the axial position is limited by the step of the tail section of the long tail nozzle shell. The convergent straight section insulation layer has a long straight section, and the inner layer is made of 2.5D carbon fiber integral woven composite material, which can better resist high-temperature gas scouring.

[0005] In the document "Experimental Study on Ablation, Scouring and Insulation of Long Nozzle of Solid Rocket Engine with Low Thrust and Long Working Time", the throat liner is located at the tail of the long tail section. It is made of tungsten-infiltrated copper, surrounded by graphite backing, graphite liner ring and insulation bushing, and axially limited by the tail cap (1Cr18NiTi). There is a long straight section in front of the throat liner, which is made of high-silicon-oxygen laminated fiberglass. The solid rocket engine charge is polysulfide rubber composite solid propellant, with an average working pressure of about 5Mpa, see Figure 1 shown.

[0006] In the document "Research and Analysis on Thermal Structural Failure of a Certain Solid-State Long Tail Nozzle", the long tail nozzle consists of a subsonic long tail pipe and a prototype nozzle, which are connected by threads; the subsonic long tail pipe convergence section is molded by composite compression molding of phenolic resin high modulus carbon fiber molded plastic and phenolic resin high silica fiber molded plastic, and the straight pipe section uses an inner layer of phenolic resin high modulus carbon fiber molded plastic and an outer layer of a wound fiberglass sleeve bonding structure. The throat liner is located at the tail of the integral long tail nozzle. It is made of tungsten infiltrated copper. It is wrapped with C / C material and pyrolytic graphite at the front and back. The outer layer is insulated with molded high silica and molded carbon fiber, and is axially limited by the step of the tail end shell (2Cr13). The working time of this solid rocket engine is about 70s, and the average working pressure is about 7Mpa. See Figure 2 shown. Summary of the invention

[0007] The technical problem to be solved by the present invention is to provide a throat liner assembly and a long tail nozzle of a solid rocket engine that can work for a long time under high pressure, which can ensure that the long tail nozzle can work reliably for a long time under high pressure, keep the nozzle structure and inner surface intact, have no ablation of the throat liner, have small thrust loss, and have high nozzle efficiency.

[0008] In order to solve the above technical problems, the technical solution adopted by the present invention is: a throat liner assembly of a solid rocket engine working for a long time under high pressure, wherein the throat liner assembly is arranged at the head of a long tail nozzle, and comprises a throat liner, a support ring, a backing liner and a thermal insulation cap, the throat liner is arranged at the intersection of the convergent section and the long tail section of the long tail nozzle shell, a support ring is arranged on the outside of the throat liner, a backing is arranged on the outside of the support ring, and a thermal insulation cap is arranged on the head of the throat liner, and the thermal insulation cap covers the end of the throat liner, the butt joint between the throat liner and the support ring, and the butt joint between the support ring and the backing.

[0009] In a preferred embodiment, the inner surface of the throat liner is an ellipsoidal surface.

[0010] In a preferred solution, the backing includes a conical section arranged in the convergent section and a straight section arranged in the long tail section, and the conical section and the straight section are an integrated structure.

[0011] In a preferred solution, the maximum outer diameter of the support ring is greater than the inner diameter of the long tail section of the long tail nozzle housing.

[0012] In a preferred solution, the throat liner is made of molybdenum-hafnium-carbon alloy.

[0013] In a preferred solution, the support ring is made of a three-dimensional fine-woven puncture carbon / carbon composite material; the heat insulation cap is made of a three-dimensional fine-woven puncture carbon / carbon composite material; and the backing is made of a high-silica / phenolic molded structure.

[0014] In a preferred solution, the throat liner head is provided with a step, and the heat insulation cap covers the step.

[0015] In a preferred solution, end steps are provided at both ends of the throat liner assembly.

[0016] The present invention also provides a long tail nozzle of a solid rocket engine that works for a long time under high pressure, including the above-mentioned throat liner assembly, the head of the throat liner assembly is provided with a convergent section insulation layer, the tail is provided with an expander section insulation layer, the convergent section insulation layer is arranged on the inner side of the convergent section of the long tail nozzle shell, the expander section insulation layer is arranged on the inner side of the long tail section of the long tail nozzle shell, and the convergent section insulation layer and the expander section insulation layer are overlapped on the end step of the throat liner assembly.

[0017] In a preferred embodiment, the inner side of the thermal insulation layer of the expansion section is an expansion profile, which gradually expands from the head to the tail, and the expansion angle of the expansion profile is 4-6°.

[0018] The throat liner assembly and long tail nozzle of a solid rocket engine working for a long time under high pressure provided by the present invention have the following beneficial effects: 1. The present invention places the throat liner in front and utilizes the convergent section of the nozzle shell to provide a larger supporting surface, which can withstand high pressure.

[0019] 2. At the same time, the throat upstream passage can be greatly shortened, reducing the impact of gas scouring.

[0020] 3. The convergent section of the nozzle shell is larger than the long tail section, the throat lining back wall insulation material is thickened, and the pressure bearing and heat insulation capabilities are further enhanced; finally, a long tail nozzle of a solid rocket engine that can work under high pressure for a long time can be obtained.

[0021] 4. The long tail nozzle of the solid rocket engine of the present invention can ensure long-term reliable operation under high pressure, and keep the nozzle structure and inner surface intact; the throat liner has no ablation, the thrust loss is small, and the nozzle efficiency is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The present invention will be further described below in conjunction with the accompanying drawings and embodiments: Figure 1 The nozzle structure diagram in the prior art document 1; Figure 2 The nozzle structure diagram in document 2 of the prior art; Figure 3 It is a schematic diagram of the structure of the nozzle of the present invention; Figure 4 It is a structural schematic diagram of the throat liner assembly of the present invention; Figure 5 It is a schematic diagram of the installation structure of the throat liner of the present invention; Figure 6 The actual measured pressure curve of a certain engine using the long tail nozzle of the present invention; In the figure: throat liner 100, step 101, support ring 200, backing 300, cone section 301, straight section 302, insulation cap 400, long tail nozzle shell 500, convergent section 501, long tail section 502, end step 600, convergent section insulation layer 700, divergent section insulation layer 800, divergent profile 801. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0024] Embodiment 1: like Figures 4 and 5 As shown, a throat liner assembly of a solid rocket engine that works for a long time under high pressure and intensity, wherein the throat liner assembly is arranged at the head of a long tail nozzle, and the throat liner is moved forward to the head of the long tail nozzle, thereby eliminating the long straight channel upstream of the throat liner and avoiding scouring and ablation of the gas flow.

[0025] The throat liner assembly includes a throat liner 100, a support ring 200, a backing 300 and a heat insulation cap 400. The throat liner 100 is arranged at the intersection of the convergent section 501 and the long tail section 502 of the long tail nozzle shell 500. The throat liner 100 is provided with a support ring 200 on the outside, and the backing 300 is provided on the outside of the support ring 200. The head of the throat liner 100 is provided with a heat insulation cap 400, and the heat insulation cap 400 covers the end of the throat liner 100, the joint seam between the throat liner 100 and the support ring 200, and the joint seam between the support ring 200 and the backing 300. The heat insulation cap 400 covers the end of the throat liner 100, the joint seam between the throat liner 100 and the support ring 200, and the joint seam between the support ring 200 and the backing 300, and plays a sealing role to prevent airflow from leaking from the joint seam.

[0026] The inner surface of the throat liner 100 is an ellipsoidal surface, which is beneficial to accelerating the convergence of the gas and reducing the energy loss of the airflow.

[0027] The throat liner 100 is made of molybdenum-hafnium-carbon alloy, which can reduce the oxidation and ablation of the throat liner by the gas and avoid changes in the throat diameter.

[0028] The backing 300 includes a conical section 301 disposed in the convergent section 501 and a straight section 302 disposed in the long tail section 502 , and the conical section 301 and the straight section 302 are an integral structure.

[0029] The conical section 301 of the backing 300 contacts the convergent section 501 of the long tail nozzle shell 500 over a large area, which can improve the pressure bearing capacity of the backing 300 .

[0030] The backing 300 adopts a high-silica / phenolic molded structure and has excellent thermal insulation performance.

[0031] The maximum outer diameter of the support ring 200 is greater than the inner diameter of the long tail section 502 of the long tail nozzle housing 500. The convergent section 501 of the long tail nozzle housing 500 can play a supporting role therefor.

[0032] The support ring 200 is made of a three-dimensional fine-woven punctured carbon / carbon composite material, which has good high-temperature mechanical properties and can bear the high pressure of the engine.

[0033] The heat insulation cap 400 is made of three-dimensional fine-woven puncture carbon / carbon composite material with high density and good strength, and can withstand the erosion of high-temperature gas flow.

[0034] Preferably, a step 101 is provided at the head of the throat liner 100 , and the heat insulation cap 400 covers the step 101 .

[0035] Preferably, both ends of the throat liner assembly are provided with end steps 600. In this embodiment, two sets of end steps 600 are provided at each end. By providing the end steps 600, the convergent section insulation layer 700 and the divergent section insulation layer 800 are butted against the throat liner assembly to prevent the gas from flowing to the conical surface of the nozzle shell.

[0036] The present invention places the throat liner in front and utilizes the convergent section 501 of the nozzle shell 500 to provide a larger support surface, which can withstand high pressure; at the same time, the upstream channel of the throat can be greatly shortened to reduce the impact of gas scour; the convergent section 501 of the nozzle shell 500 is larger than the long tail section, and the back wall insulation material of the throat liner 100 is thickened, and the pressure-bearing and heat-insulating capabilities are further enhanced; finally, a solid rocket engine long tail nozzle that can work for a long time under high pressure can be obtained.

[0037] Embodiment 2: like Figure 3 As shown, a long tail nozzle of a solid rocket engine working for a long time under high pressure includes the throat liner assembly described in Example 1, the head of the throat liner assembly is provided with a convergent section insulation layer 700, and the tail is provided with an expansion section insulation layer 800, the convergent section insulation layer 700 is arranged on the inner side of the convergent section 501 of the long tail nozzle shell 500, and the expansion section insulation layer 800 is arranged on the inner side of the long tail section 502 of the long tail nozzle shell 500.

[0038] Both ends of the throat liner assembly are provided with end steps 600. The end steps 600 located at the convergent section 501 are distributed at the ends of the insulation cap 400 and the backing 300. The convergent section insulation layer 700 covers the insulation cap 400. The inner diameter of the step of the convergent section insulation layer 700 is smaller than the outer diameter of the end step 600 corresponding to the insulation cap 400, so that the convergent section insulation layer 700 overlaps the insulation cap 400 to prevent the insulation cap 400 from falling off. The two steps between the convergent section insulation layer 700 and the throat liner assembly are butt-jointed to prevent the gas from flowing to the conical surface of the nozzle shell.

[0039] The inner side of the expansion section insulation layer 800 is an expansion surface 801, which gradually expands from the head to the tail. The expansion angle of the expansion surface 801 is 4~6°. In the present embodiment, the expansion angle of the expansion surface 801 is 5.4°. Under the conditions of the outer diameter and length of the long tail nozzle, and the throat diameter and the outlet diameter being determined, the thickness of the insulation material outside the expansion surface can be thickened, which can effectively reduce the temperature of the outer wall of the nozzle.

[0040] The expansion section insulation layer 800 is made of high-silicon / phenolic molded products, and has excellent airflow erosion resistance under the effect of aluminum-free propellant formula.

[0041] A combustion test was conducted on a solid rocket engine using the long tail nozzle. The average working pressure of the engine reached 10 MPa, no ablation occurred in the throat, the throat diameter remained unchanged, the working time was 70 seconds, and the pressure curve was shown in FIG. Figure 6 shown.

[0042] The long tail nozzle of the solid rocket engine of the present invention can ensure long-term reliable operation under high pressure and keep the nozzle structure and inner surface intact; the throat liner has no ablation, the thrust loss is small, and the nozzle efficiency is high.

[0043] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A throat liner assembly for a solid rocket engine that works for a long time under high pressure, characterized in that: The throat liner assembly is arranged at the head of the long tail nozzle, and comprises a throat liner (100), a support ring (200), a backing liner (300) and a heat insulation cap (400); the throat liner (100) is arranged at the intersection of the convergent section (501) and the long tail section (502) of the long tail nozzle shell (500); a support ring (200) is arranged on the outside of the throat liner (100); a backing liner (300) is arranged on the outside of the support ring (200); a heat insulation cap (400) is arranged on the head of the throat liner (100); the heat insulation cap (400) covers the end of the throat liner (100), the joint between the throat liner (100) and the support ring (200), and the joint between the support ring (200) and the backing liner (300).

2. A throat liner assembly for a solid rocket engine operating under high pressure for a long time according to claim 1, characterized in that: The inner profile of the throat liner (100) is an ellipsoidal surface.

3. A throat liner assembly for a solid rocket engine operating under high pressure for a long time according to claim 1, characterized in that: The backing (300) comprises a conical section (301) arranged in the convergent section (501) and a straight section (302) arranged in the long tail section (502); the conical section (301) and the straight section (302) are an integrated structure.

4. A throat liner assembly for a solid rocket engine operating under high pressure for a long time according to claim 1, characterized in that: The maximum outer diameter of the support ring (200) is greater than the inner diameter of the long tail section (502) of the long tail nozzle housing (500).

5. A throat liner assembly for a solid rocket engine operating under high pressure for a long time according to claim 1, characterized in that: The throat liner (100) is made of molybdenum-hafnium-carbon alloy.

6. A throat liner assembly for a solid rocket engine operating under high pressure for a long time according to claim 1, characterized in that: The support ring (200) adopts a three-dimensional fine-woven puncture carbon / carbon composite material; the heat insulation cap (400) adopts a three-dimensional fine-woven puncture carbon / carbon composite material; and the backing (300) adopts a high-silicon / phenolic molded structure.

7. A throat liner assembly for a solid rocket engine operating under high pressure for a long time according to claim 1, characterized in that: The throat liner (100) is provided with a step (101) at the head thereof, and the heat insulation cap (400) covers the step (101).

8. The throat liner assembly of a solid rocket engine operating under high pressure for a long time according to claim 1, characterized in that: End steps (600) are provided at both ends of the throat liner assembly.

9. A long tail nozzle of a solid rocket engine working for a long time under high pressure, characterized in that: The throat liner assembly comprises the throat liner assembly as claimed in any one of claims 1 to 8, wherein a convergent section insulation layer (700) is provided at the head of the throat liner assembly, and an divergent section insulation layer (800) is provided at the tail, the convergent section insulation layer (700) is arranged on the inner side of the convergent section (501) of the long tail nozzle shell (500), and the divergent section insulation layer (800) is arranged on the inner side of the long tail section (502) of the long tail nozzle shell (500), and the convergent section insulation layer (700) and the divergent section insulation layer (800) are overlapped on the end step (600) of the throat liner assembly.

10. The long tail nozzle of a solid rocket engine operating under high pressure for a long time according to claim 9, characterized in that: The inner side of the expansion section heat insulation layer (800) is an expansion profile (801), which gradually expands from the head to the tail, and the expansion angle of the expansion profile (801) is 4-6 degrees.

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