Single chamber dual thrust solid motor and its nozzle

Abstract

The application relates to the technical field of solid engine, in particular to a single-chamber double-thrust solid engine and a nozzle thereof, which comprises a nozzle shell, a tailpipe heat insulation sleeve, an expansion section heat insulation sleeve and a throat liner. The throat liner comprises a front section throat liner, an ablation throat liner, a middle section throat liner and a rear section throat liner. The thermal conductivities of the front section throat liner and the rear section throat liner are lower than that of the middle section throat liner. The application can guarantee the two-stage thrust ratio requirement of the solid engine.

Description

Technical Field

[0001] This application relates to the field of solid rocket motor technology, and in particular to a single-chamber dual-thrust solid rocket motor and its nozzle. Background Technology

[0002] A single-chamber, dual-thrust solid rocket motor can be simply described as a single solid rocket motor that achieves two stages of thrust by using propellants with different burning rates or through propellant design. When the solid rocket motor ignites, the first-stage propellant burns, generating the first-stage thrust. After the first-stage propellant burns, the second-stage propellant ignites, generating the second-stage thrust. Generally, the first stage of a solid rocket motor's operation is characterized by high thrust and short duration, often achieved by using high-burning-rate propellants or increasing the burning surface area of ​​the first-stage propellant grain. The second stage of a solid rocket motor's operation is characterized by low thrust and long endurance, often achieved by using low-burning-rate propellants or propellant grains with a small burning surface area.

[0003] The nozzle is the energy conversion device of a solid rocket motor. Its main function is to control the mass flow rate of the combustion gas through the throat area of ​​the nozzle, maintain the gas pressure in the combustion chamber of the solid rocket motor at a predetermined level, ensure the normal combustion of the propellant, accelerate the expansion of the propellant combustion products, and fully convert its thermal energy into the kinetic energy of the gas. The high-speed ejection of the gas generates reaction thrust. For solid rocket motors of some special tactical weapons, the design of the propellant charge is limited by diameter, length, and other factors, making it difficult to guarantee the required two-stage thrust ratio. Therefore, how to ensure the required two-stage thrust ratio of solid rocket motors is a technical problem that needs to be solved by those skilled in the art. Summary of the Invention

[0004] In view of this, this application provides a single-chamber dual-thrust solid rocket motor nozzle to ensure the two-stage thrust ratio requirement of the solid rocket motor.

[0005] To solve the above-mentioned technical problems, this application provides the following technical solution:

[0006] A single-chamber, dual-thrust solid rocket motor nozzle includes: a nozzle housing, a tailpipe insulating sleeve, an expansion section insulating sleeve, and a throat liner. The throat liner includes: a front throat liner, an ablation throat liner, a middle throat liner, and a rear throat liner. The thermal conductivity of the front and rear throat liners is lower than that of the middle throat liner. The expansion section insulating sleeve is fixed within the nozzle housing and has a throat liner mounting hole with a limiting step within it. The throat liner is fixed within the throat liner mounting hole of the expansion section insulating sleeve, and the rear throat liner mates with the limiting step within the throat liner mounting hole. The front throat liner mates with the portion of the throat liner before the limiting step within the throat liner mounting hole. The rear throat liner has a middle throat liner mounting hole with a limiting step within it. The front throat liner has... There is an ablation throat liner mating hole, the rear end face of the front throat liner is in contact with the front end face of the rear throat liner, and the rear end face of the front throat liner has a middle throat liner fixing groove; the middle throat liner is fixed in the middle throat liner mounting hole of the rear throat liner and mates with the limiting step in the middle throat liner mounting hole, and the front end of the middle throat liner is inserted into the middle throat liner fixing groove on the rear end face of the front throat liner; the ablation throat liner is fixed in the ablation throat liner mating hole of the front throat liner, and its rear end mates with the front conical surface of the middle throat liner; the tailpipe insulation sleeve is fixed in the nozzle housing, and the part of the rear end face of the tailpipe insulation sleeve near the inner side mates with the conical surface of the front part of the ablation throat liner mating hole of the front throat liner, and the part near the outer side mates with the front end of the expansion section insulation sleeve.

[0007] In the single-chamber dual-thrust solid rocket motor nozzle described above, preferably, the ablation throat liner is made of a non-metallic ablation material or an ultra-low burning rate high-strength propellant, and the ablation throat liner serves as the engine's primary throat liner.

[0008] In the single-chamber dual-thrust solid rocket motor nozzle described above, preferably, the middle throat liner is made of tungsten-copper infiltrated material or TZM molybdenum alloy material, serving as the engine's secondary throat liner. The rear throat liner is made of C / C composite material, and the front throat liner is also made of C / C composite material, used to fix and constrain the middle throat liner.

[0009] In the single-chamber dual-thrust solid rocket motor nozzle described above, preferably, the limiting step in the throat liner mounting hole of the expansion section insulation sleeve is a conical limiting step, and the large end of the conical limiting step in the throat liner mounting hole faces forward; the outer diameter of the rear section of the rear throat liner gradually decreases from front to back to mate with the conical limiting step in the throat liner mounting hole; the diameter of the portion before the limiting step in the throat liner mounting hole remains unchanged; the outer diameter of the front section of the rear throat liner remains unchanged to mate with the throat liner mounting hole; and the outer diameter of the front section of the throat liner remains unchanged to mate with the throat liner mounting hole.

[0010] In the single-chamber dual-thrust solid rocket motor nozzle described above, preferably, the limiting step in the middle throat liner mounting hole of the rear throat liner is a conical limiting step, and the large end of the conical limiting step in the middle throat liner mounting hole faces forward; the rear section of the middle throat liner mates with the conical limiting step in the middle throat liner mounting hole.

[0011] In the single-chamber dual-thrust solid rocket motor nozzle described above, preferably, the diameter of the portion near the front of the middle throat liner mounting hole before the limiting step gradually decreases from front to back, while the diameter of the portion near the rear of the portion before the limiting step remains unchanged; the outer diameter of the front portion of the middle throat liner near the front gradually decreases from front to back to match the front portion of the middle throat liner mounting hole, while the outer diameter of the front portion of the middle throat liner near the rear remains unchanged to match the rear portion of the front portion of the middle throat liner mounting hole.

[0012] In the single-chamber dual-thrust solid rocket motor nozzle described above, preferably, the diameter of the rear portion of the ablation throat liner mating hole of the front throat liner remains unchanged; the outer diameter of the front section of the ablation throat liner remains unchanged to mate with the rear portion of the ablation throat liner mating hole of the front throat liner; the outer diameter of the rear section of the ablation throat liner gradually decreases from front to rear to mate with the front conical surface of the rear end of the middle throat liner.

[0013] In the single-chamber dual-thrust solid rocket motor nozzle described above, preferably, the diameter of the front portion of the ablation throat liner mating hole of the front throat liner gradually decreases from front to back, and the rear end face of the tailpipe insulation sleeve near the inner side is a slope that gradually slopes inward from front to back, so as to mate with the front portion of the ablation throat liner mating hole of the front throat liner.

[0014] In the single-chamber dual-thrust solid rocket motor nozzle described above, preferably, the inclined surface of the rear end face of the tailpipe insulation sleeve near the inner side extends into the front portion of the ablation throat liner hole to press and fix the ablation throat liner.

[0015] A single-chamber dual-thrust solid rocket motor includes: a combustion chamber housing and a single-chamber dual-thrust solid rocket motor nozzle as described in any one of the above claims, wherein the single-chamber dual-thrust solid rocket motor nozzle is connected to the combustion chamber housing.

[0016] Compared to the aforementioned background technology, the single-chamber dual-thrust solid rocket motor and its nozzle provided in this application can guarantee the two-stage thrust ratio requirement of the solid rocket motor. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings.

[0018] Figure 1 This is a schematic diagram of a single-chamber dual-thrust solid rocket motor nozzle provided in an embodiment of this application.

[0019] Among them, 110-nozzle housing, 120-tailpipe insulation sleeve, 130-expansion section insulation sleeve, 140-throat liner, 141-front throat liner, 142-ablation throat liner, 143-middle throat liner, and 144-rear throat liner. Detailed Implementation

[0020] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0021] In addition, spatial relation terms such as "upper," "lower," "front," and "rear" are used for ease of description to explain the positional relationship between two components. In this application, "front" refers to the direction toward the combustion chamber, and "rear" refers to the direction toward the nozzle exit.

[0022] Please see Figure 1 , Figure 1 This is a schematic diagram of a single-chamber dual-thrust solid rocket motor nozzle provided in an embodiment of this application.

[0023] This application provides a single-chamber dual-thrust solid rocket motor nozzle, including: a nozzle housing 110, a tailpipe insulation sleeve 120, an expansion section insulation sleeve 130, and a throat liner 140. The throat liner 140 includes: a front throat liner 141, an ablation throat liner 142, a middle throat liner 143, and a rear throat liner 144.

[0024] The expansion section insulation sleeve 130 is fixed inside the nozzle housing 110. The nozzle housing 110 is connected to the combustion chamber housing of the single-chamber dual-thrust solid rocket motor, and the nozzle housing 110 constrains the tailpipe insulation sleeve 120, the expansion section insulation sleeve 130, and the throat liner 140 inside it, while also realizing the thrust transmission function. Optionally, the nozzle housing 110 is made of 30CrMnSiA alloy steel.

[0025] Furthermore, the expansion section insulation sleeve 130 has throat liner mounting holes extending through both ends. Each throat liner mounting hole contains a limiting step. The limiting step within the throat liner mounting hole, and the portion preceding the limiting step, are used to accommodate and fix the throat liner 140, providing effective support for the throat liner 140. Optionally, the limiting step within the throat liner mounting hole of the expansion section insulation sleeve 130 is a conical limiting step, with the larger end of the conical limiting step facing forward. Alternatively, the diameter of the portion preceding the limiting step within the throat liner mounting hole remains unchanged, allowing it to contact the front section of the rear throat liner 144 and the front throat liner 141. Still alternatively, the throat liner mounting hole also has a front limiting step, and this front limiting step is located before the limiting step within the throat liner mounting hole, thus restricting the front throat liner 141. Specifically, the diameter of the portion of the throat liner mounting hole preceding the limiting step, closer to the front, is larger than the diameter of the portion closer to the rear, thus forming a front limiting step in the portion preceding the limiting step within the throat liner mounting hole. Furthermore, the diameter of the portion of the throat liner mounting hole following the limiting step gradually increases from front to back to maintain the expansion section profile.

[0026] Alternatively, the expansion section insulation sleeve 130 may be made of a high-silica / phenolic molding material, which not only provides effective support for the throat liner 140 and generates thrust during solid rocket motor operation, but also serves as a heat insulation layer. Furthermore, the front end face of the expansion section insulation sleeve 130 is designed to mate with the outer portion of the rear end face of the tailpipe insulation sleeve 120, together with the tailpipe insulation sleeve 120, forming the insulation layer for the single-chamber dual-thrust solid rocket motor nozzle.

[0027] The rear throat liner 144 has a middle throat liner mounting hole extending through both ends. The middle throat liner mounting hole contains a limiting step. The limiting step and the portion preceding it are used to accommodate and fix the middle throat liner 143, providing effective support for the middle throat liner 143. Optionally, the limiting step within the middle throat liner mounting hole is a conical limiting step, with the larger end of the conical limiting step facing forward to limit the rear section of the middle throat liner 143. Alternatively, the diameter of the portion of the middle throat liner mounting hole preceding the limiting step, closer to the front, gradually decreases from front to back to mate with the front portion of the middle throat liner 143, while the diameter of the portion of the middle throat liner mounting hole preceding the limiting step, closer to the rear, remains unchanged to mate with the rear portion of the front section of the middle throat liner 143. Still alternatively, the diameter of the portion of the middle throat liner mounting hole following the limiting step gradually increases from front to back to maintain the expansion section profile.

[0028] Optionally, the thermal conductivity of the rear throat liner 144 is lower than that of the middle throat liner 143, so as to effectively reduce the heat exchange from the middle throat liner 143 to the rear throat liner 144. Alternatively, the rear throat liner 144 may be made of C / C composite material.

[0029] The front throat liner 141 has a through-hole for ablation throat liner mating. The front portion of the ablation throat liner mating hole is conical, used to mate with the inner part of the rear end face of the tailpipe insulation sleeve 120. The rear portion of the ablation throat liner mating hole is used to fix the ablation throat liner 142, providing effective support for the ablation throat liner 142. The rear end face of the front throat liner 141 mates with the front end face of the rear throat liner 144. The rear end face of the front throat liner 141 also has a middle throat liner fixing groove for inserting the front end of the middle throat liner 143, which mates with the rear throat liner 144 to fix the middle throat liner 143. Optionally, the diameter of the front portion of the ablation throat liner mating hole gradually decreases from front to back, forming a conical surface, so that the rear end face of the tailpipe insulation sleeve 120 contacts and presses against the front throat liner 141, while the diameter of the rear portion of the ablation throat liner mating hole remains unchanged. Additionally, the front end face of the front throat liner 141 contacts the middle portion of the rear end face of the tailpipe insulation sleeve 120. Optionally, the front end face of the front throat liner 141 has a step so as to contact the step at the middle of the rear end face of the tailpipe insulation sleeve 120.

[0030] Optionally, the thermal conductivity of the front throat liner 141 is lower than that of the middle throat liner 143, and its strength and stability at high temperatures are superior to those of the tailpipe insulation sleeve 120. This effectively constrains the middle throat liner 143, protects the tailpipe insulation sleeve 120 from excessive pyrolysis, and achieves a smooth transition from the tailpipe insulation sleeve 120 to the middle throat liner 143. Alternatively, the front throat liner 141 may be made of C / C composite material.

[0031] The mid-section throat liner 143 is fixed to the mid-section throat liner mounting hole of the rear throat liner 144 and engages with the limiting step within the mid-section throat liner mounting hole. The front end of the mid-section throat liner 143 is inserted into the mid-section throat liner fixing groove on the rear end face of the front throat liner 141, thereby fixing the mid-section throat liner 143 through the engagement of the front throat liner 141 and the rear throat liner 144. Optionally, the outer diameter of the front portion of the mid-section throat liner 143 near the front gradually decreases from front to rear to engage with the front portion of the mid-section throat liner mounting hole of the rear throat liner 144, while the outer diameter of the front portion of the mid-section throat liner 143 near the rear remains unchanged to engage with the front portion of the mid-section throat liner mounting hole near the rear.

[0032] The middle throat liner 143 has a second throat liner hole that runs through both the front and rear ends. The front part of the second throat liner hole is a front conical surface, meaning that the diameter of the front part of the second throat liner hole gradually increases from back to front, which is used to mate with the rear end of the ablation throat liner 142 and provide effective support for the ablation throat liner 142. In addition, the rear part of the second throat liner hole is a rear conical surface, meaning that the diameter of the rear part of the second throat liner hole gradually increases from front to back, in order to maintain the expansion section profile.

[0033] Optionally, the mid-section throat liner 143 can be made of tungsten-copper infiltrated material or TZM molybdenum alloy material, serving as the throat liner for the second stage of solid rocket motor operation. According to tungsten-copper infiltrated ablation test data, the tungsten-copper infiltrated ablation rate is 0.002 mm / s. The duration of the solid rocket motor's second stage operation is 100 s, and the ablation amount of the mid-section throat liner 143 is only 0.2 mm, effectively ensuring the stability of the solid rocket motor's second-stage thrust.

[0034] The ablation throat liner 142 is fixed in the ablation throat liner mating hole of the front throat liner 141, and the rear end of the ablation throat liner 142 mates with the front conical surface of the middle throat liner 143. Optionally, the outer diameter of the front section of the ablation throat liner 142 remains unchanged to mate with the rear part of the ablation throat liner mating hole of the front throat liner 141; the outer diameter of the rear section of the ablation throat liner 142 gradually decreases from front to rear to mate with the front conical surface of the middle throat liner.

[0035] The ablation throat liner 142 has a first throat liner hole extending through both its front and rear ends. The front portion of the first throat liner hole is a front conical surface, meaning the diameter of the front portion gradually decreases from front to back, while the rear portion is a rear conical surface, meaning the diameter of the rear portion gradually increases from front to back, to maintain the expansion section profile. The ablation throat liner 142 is made of an ablation-compatible material and serves as the throat liner for the first stage of solid rocket motor operation. Optionally, the ablation throat liner 142 can be made of chopped fiber / phenolic molding material or ultra-low burning rate high-strength propellant. The ablation products of the molding material are similar to those of the converging section's adiabatic ablation and have no impact on the normal operation of the solid rocket motor; the combustion products of the ultra-low burning rate high-strength propellant have the same composition as the combustion gases produced by the solid rocket motor and have no impact on the normal operation of the solid rocket motor.

[0036] For example, a certain high-silica fiber / phenolic molding material has an ablation rate of 0.35 mm / s, and ultra-low burning rate high-strength propellant can achieve a burning rate adjustment of 0.5 mm / s to 2 mm / s. Based on the first-stage working time of the solid rocket motor, the ablation throat liner material is selected, which can achieve a smooth transition from the first-stage expansion ratio to the second-stage expansion ratio of the nozzle of a single-chamber dual-thrust solid rocket motor.

[0037] The throat liner 140 is fixed inside the throat liner mounting hole of the expansion section insulation sleeve, and the rear throat liner 144 mates with the limiting step inside the throat liner mounting hole, while the front throat liner 141 mates with the portion of the throat liner mounting hole before the limiting step. Optionally, the outer diameter of the rear section of the rear throat liner 144 gradually decreases from front to rear to mate with the tapered limiting step inside the throat liner mounting hole of the expansion section insulation sleeve; the outer diameter of the front section of the rear throat liner 144 remains unchanged to mate with the front portion of the throat liner mounting hole of the expansion section insulation sleeve; and the outer diameter of the front throat liner 141 remains unchanged to mate with the front portion of the throat liner mounting hole of the expansion section insulation sleeve.

[0038] The tailpipe insulation sleeve 120 has a tailpipe insulation sleeve hole that extends through both ends, used to inject high-temperature, high-pressure combustion gas from the combustion chamber. The tailpipe insulation sleeve 120 is fixed inside the nozzle housing 110, and the inner portion of the rear end face of the tailpipe insulation sleeve 120 engages with the conical surface of the front portion of the ablation throat liner mating hole of the front throat liner 141. The middle portion of the rear end face of the tailpipe insulation sleeve 120 contacts the front end face of the front throat liner 141, and the outer portion of the rear end face of the tailpipe insulation sleeve 120 contacts the front end face of the expansion section insulation sleeve 130. Optionally, the middle portion of the rear end face of the tailpipe insulation sleeve 120 forms a step for contacting and engaging with the stepped front end face of the front throat liner 141. Optionally, the outer portion of the rear end face of the tailpipe insulation sleeve 120 forms a step with the middle portion of the tailpipe insulation sleeve 120, so that the contact between the rear end face of the tailpipe insulation sleeve 120 and the front end face of the expansion section insulation sleeve 130, and the contact between the middle portion of the rear end face of the tailpipe insulation sleeve 120 and the front end face of the front throat liner 141, are on different surfaces. Optionally, the inner portion of the rear end face of the tailpipe insulation sleeve 120 is a slope that gradually slopes inward from front to back, so as to mate with the conical surface of the front portion of the ablation throat liner mating hole of the front throat liner 141. Optionally still, the inner slope of the rear end face of the tailpipe insulation sleeve 120 also extends into the front portion of the first throat liner hole of the ablation throat liner 142, near the front, to a certain extent to compress and fix the ablation throat liner 142, making the ablation throat liner 142 more stable.

[0039] Optionally, the tailpipe insulation sleeve 120 is made of a high-silica / phenolic-carbon fiber / phenolic composite molding material. The inner layer of the tailpipe insulation sleeve 120 is made of polyacrylonitrile fiber / phenolic molding material, which, due to its excellent erosion resistance, ensures the integrity of the tailpipe structure during engine operation. The outer layer of the tailpipe insulation sleeve 120 is made of a high-silica / phenolic molding material, whose low thermal conductivity can isolate the heat inside the engine from the outside, keeping the nozzle housing within the allowable temperature range.

[0040] This application also provides a single-chamber dual-thrust solid rocket motor, comprising: a combustion chamber housing and the aforementioned single-chamber dual-thrust solid rocket motor nozzle, wherein the single-chamber dual-thrust solid rocket motor nozzle is connected to the combustion chamber housing to form a single-chamber dual-thrust solid rocket motor.

[0041] like Figure 1As shown in Figure (a), the throat liner of a single-chamber dual-thrust solid rocket motor is used in the first stage of operation. In this first stage, high-burning-rate propellants and large combustion surfaces are typically employed to achieve high thrust. The throat diameter in the first stage is the minimum diameter of the first throat liner hole in the ablated throat liner 143. At this point, the throat diameter is small, and the expansion ratio is large, reaching 7, which can maintain the high operating pressure of the single-chamber dual-thrust solid rocket motor in the first stage and effectively guarantee its high thrust. Because the ablated throat liner 143 is made of an ablation-resistant material, the throat diameter gradually increases and the expansion ratio slowly decreases as the single-chamber dual-thrust solid rocket motor operates. At the end of the first stage, the expansion ratio decreases to 4, meeting the requirements for the second stage of operation of the single-chamber dual-thrust solid rocket motor.

[0042] like Figure 1 As shown in Figure (b), the throat liner of a single-chamber dual-thrust solid rocket motor is used in the second stage of operation. In this stage, the motor typically employs low burning rate, constant burning surface, and a stable nozzle expansion ratio to achieve the goal of low thrust and long endurance. The throat liner for this second stage is the mid-section throat liner 143, which uses tungsten-copper infiltrated material or TZM molybdenum alloy material with extremely low ablation rates. Even after hundreds of seconds of operation, the throat area and expansion ratio change very little.

[0043] This application achieves a large expansion ratio in the nozzle and a high operating pressure in the combustion chamber during the first stage of operation of a single-nozzle solid rocket motor by employing a small-diameter ablative throat liner 142, thus ensuring high thrust during takeoff. Furthermore, the ablative throat liner 142 facilitates the transition of the expansion ratio from the first to the second stage of operation, allowing the solid rocket motor to enter the second stage. By employing a large-diameter mid-section throat liner 143, the application achieves a smaller expansion ratio in the nozzle during the second stage of operation, fulfilling the requirements of stable low thrust and long endurance in the second stage. This application not only guarantees the two-stage thrust ratio requirements of the solid rocket motor but also simplifies its structure, resulting in higher reliability and lower cost.

[0044] It will be apparent to those skilled in the art that this application is not limited to the details of the exemplary embodiments described above, and that this application can be implemented in other specific forms without departing from the spirit or essential characteristics of this application. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this application is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within this application. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0045] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A single-chamber, dual-thrust solid rocket motor nozzle, characterized in that, include: The nozzle housing, tailpipe insulation sleeve, expansion section insulation sleeve, and throat liner, the throat liner including: front throat liner, ablation throat liner, middle throat liner and rear throat liner, the thermal conductivity of the front throat liner and the rear throat liner is lower than that of the middle throat liner. The expansion section insulation sleeve is fixed inside the nozzle housing, and the expansion section insulation sleeve has a throat liner mounting hole with a limiting step inside the throat liner mounting hole; the throat liner is fixed inside the throat liner mounting hole of the expansion section insulation sleeve, and the rear throat liner engages with the limiting step inside the throat liner mounting hole, and the front throat liner engages with the part before the limiting step inside the throat liner mounting hole. The rear throat liner has a middle throat liner mounting hole with a limiting step inside the mounting hole; the front throat liner has an ablation throat liner mating hole, the rear end face of the front throat liner mates with the front end face of the rear throat liner, and the rear end face of the front throat liner has a middle throat liner fixing groove; the middle throat liner is fixed in the middle throat liner mounting hole of the rear throat liner and mates with the limiting step inside the middle throat liner mounting hole, and the front end of the middle throat liner is inserted into the middle throat liner fixing groove on the rear end face of the front throat liner; the ablation throat liner is fixed in the ablation throat liner mating hole of the front throat liner, and its rear end mates with the front conical surface of the middle throat liner; The tailpipe insulation sleeve is fixed inside the nozzle housing, and the inner part of the rear end face of the tailpipe insulation sleeve mates with the conical surface of the front part of the ablation throat liner mating hole of the front throat liner, while the outer part mates with the front end of the expansion section insulation sleeve.

2. The single-chamber dual-thrust solid rocket motor nozzle according to claim 1, characterized in that, The ablation throat liner is made of non-metallic ablation material or ultra-low burning rate high-strength propellant, and serves as the primary throat liner of the engine.

3. The single-chamber dual-thrust solid rocket motor nozzle according to claim 2, characterized in that, The middle throat liner is made of tungsten-copper alloy or TZM molybdenum alloy. As the secondary throat liner of the engine, the rear throat liner is made of C / C composite material, and the front throat liner is also made of C / C composite material. These materials are used to fix and constrain the middle throat liner.

4. The single-chamber dual-thrust solid rocket motor nozzle according to claim 2 or 3, characterized in that, The limiting step in the throat liner mounting hole of the expansion section insulation jacket is a conical limiting step, and the large end of the conical limiting step in the throat liner mounting hole faces forward; the outer diameter of the rear section of the rear throat liner gradually decreases from front to back to match the conical limiting step in the throat liner mounting hole. The diameter of the portion before the limiting step inside the throat liner mounting hole remains unchanged; the outer diameter of the front section of the rear throat liner remains unchanged to match the throat liner mounting hole; the outer diameter of the front throat liner remains unchanged to match the throat liner mounting hole.

5. The single-chamber dual-thrust solid rocket motor nozzle according to claim 2 or 3, characterized in that, The limiting step in the middle section throat liner mounting hole of the rear throat liner is a conical limiting step, and the large end of the conical limiting step in the middle section throat liner mounting hole faces forward. The rear section of the middle throat liner mates with the tapered limiting step inside the installation hole of the middle throat liner.

6. The single-chamber dual-thrust solid rocket motor nozzle according to claim 5, characterized in that, The diameter of the portion of the throat liner installation hole before the limiting step gradually decreases from front to back, while the diameter of the portion of the throat liner installation hole before the limiting step remains unchanged. The outer diameter of the front section of the middle throat liner, near the front, gradually decreases from front to back to match the front part of the middle throat liner mounting hole. The outer diameter of the front section of the middle throat liner, near the rear, remains unchanged to match the front part of the middle throat liner mounting hole.

7. The single-chamber dual-thrust solid rocket motor nozzle according to claim 2 or 3, characterized in that, The diameter of the rear part of the throat liner mating hole remains unchanged after the ablation of the front throat liner. The outer diameter of the front section of the ablation throat liner remains unchanged to mate with the rear part of the ablation throat liner mating hole of the front section throat liner; the outer diameter of the rear section of the ablation throat liner gradually decreases from front to back to mate with the front conical surface of the rear end of the middle section throat liner.

8. The single-chamber dual-thrust solid rocket motor nozzle according to claim 2 or 3, characterized in that, The diameter of the front part of the ablation throat liner mating hole of the front throat liner gradually decreases from front to back. The rear end face of the tailpipe insulation sleeve near the inner side is a slope that gradually slopes inward from front to back, so as to mate with the front part of the ablation throat liner mating hole of the front throat liner.

9. The single-chamber dual-thrust solid rocket motor nozzle according to claim 8, characterized in that, The front end face of the front throat liner has a step, and the middle part of the rear end face of the tailpipe insulation sleeve has a step. The step on the front end face of the front throat liner matches the step on the middle part of the rear end face of the tailpipe insulation sleeve.

10. A single-chamber, dual-thrust solid rocket motor, characterized in that, include: The combustion chamber housing and the single-chamber dual-thrust solid rocket motor nozzle according to any one of claims 1-9, wherein the single-chamber dual-thrust solid rocket motor nozzle is connected to the combustion chamber housing.

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