Thrust-adjustable charging structure of solid rocket engine

Abstract

A thrust-adjustable charging structure of a solid rocket engine comprises a combustion chamber shell, a barrel section heat insulation layer, a grain and a thickened section heat insulation layer, the position of the thickened section heat insulation layer is changed, the thickness of the heat insulation layer is utilized to change a retreating combustion surface Ab of the grain, and then the thrust of the solid rocket engine is continuously adjustable. Different working modes are realized; the thickened section heat insulation layer is located at the head, and a boosting-endurance working mode is achieved; the thickened section heat insulation layer is positioned at the tail part, so that a boosting-accelerating working mode is realized; the grain length L and the grain outer diameter D of the thrust-adjustable charging structure meet L / Dlt; the method comprises the following steps: 1, obtaining a stable thrust curve; according to the thrust-adjustable charging structure, the low-burning-speed propellant grain is adopted to replace a thickened section heat insulation layer, and then the charging ratio of a combustion chamber is increased. According to the thrust-adjustable charging structure provided by the invention, the thrust of a small solid rocket engine is continuously adjusted, the negative mass is greatly reduced, and the impulse mass ratio of the engine is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of grain design of solid rocket motors, and more specifically, to a thrust adjustable charge structure for a solid rocket motor. Background Art

[0002] Solid rocket motors are widely used in missile power devices due to their outstanding advantages such as simple structure, reliable operation, safe use, low cost, and high mobility. In the modern complex battlefield environment, in order to cope with the strong attacks of high-altitude and high-speed missiles and aircraft, it is required that missiles have high intelligence, mobility, and flexibility.

[0003] Thrust adjustable technology can adjust the thrust according to combat requirements during the operation of a solid rocket motor, realizing flexible trajectory change, attitude adjustment, and speed change of the missile, so as to achieve the capabilities of large maneuverability and strong penetration. At present, thrust adjustment technologies such as swing nozzles, throat plugs, and fluid throats are often used, which are only applicable to the thrust regulation of medium and large missile motors. Due to the limitations of missile structure and weight, it is difficult to meet the requirements of high thrust-to-mass ratio for small missiles. By changing the size of the burning surface, the continuous adjustment of the thrust of a small missile motor can be flexibly achieved on the premise of increasing a small amount of negative mass. Summary of the Invention

[0004] To solve the above problems, the present invention proposes a thrust adjustable charge structure for a solid rocket motor. The charge insulation layer adopts a variable thickness design to change the recession burning surface A during the burning process of the grain, so as to achieve continuous adjustment of the thrust of the solid rocket motor. The specific technical solutions are as follows: b The size is realized, and the continuous adjustment of the thrust of the solid rocket motor is achieved. The specific technical solutions are as follows:

[0005] A thrust adjustable charge structure for a solid rocket motor, the thrust adjustable charge structure includes a combustion chamber shell, a cylinder section insulation layer, a grain, and a thickened section insulation layer. By changing the position of the thickened section insulation layer, the change of the recession burning surface of the grain is realized by using the thickness of the insulation layer, and then the continuous adjustment of the thrust of the solid rocket motor is achieved, realizing different working modes;

[0006] The working modes include a boost-sustainment working mode and a boost-acceleration working mode;

[0007] Further, the thickened section insulation layer is located at the head to achieve the boost-sustainment working mode;

[0008] Further, the thickened section insulation layer is located at the tail to achieve the boost-acceleration working mode;

[0009] The thrust adjustable charge structure of the solid rocket motor uses a low burn rate propellant grain to replace the thickened section insulation layer. On the basis of realizing the boost-sustainment working mode and the boost-acceleration working mode of the solid rocket motor, the chamber loading ratio is also increased;

[0010] Furthermore, the low burning rate propellant grain is located at the head to achieve the boost-sustained flight working mode;

[0011] Furthermore, the low burning rate propellant grain is located at the tail to achieve the boost-acceleration working mode.

[0012] Furthermore, the combustion chamber shell is made of high-strength alloy steel, the insulation layers of the cylinder section and the thickened section are made of ethylene propylene diene monomer (EPDM) rubber, and the grain is made of high burning rate propellant.

[0013] The thrust F generated by the thrust adjustable charge structure is related to the characteristic velocity C* of the propellant, the density ρ P , the burning rate r, the nozzle efficiency C F and the burning surface area A b as follows:

[0014] F = C F C * ρ P A b r

[0015] It can be seen from the above formula that when the propellant (characteristic velocity C*, density ρ P , burning rate r) and the nozzle (nozzle efficiency C F ) are selected, the larger the burning surface area, the greater the thrust; the smaller the burning surface area, the smaller the thrust.

[0016] Furthermore, the relationship between the burning surface area A b at any time of the thrust adjustable charge structure and the initial burning surface area A 0 of the charge, the inner diameter d of the grain, the length L of the grain, and the burning layer thickness e is:

[0017] A b = A 0 + 2π(L - d)e - 3πe 2

[0018] When the grain length L and the grain outer diameter D satisfy L / D < 1, an approximately stable thrust curve can be obtained.

[0019] Compared with the prior art, the beneficial effects achieved by the present invention are as follows:

[0020] (1) The present invention adopts a variable thickness insulation layer structure to control the burning surface area of the grain, further realizes the adjustment of the thrust, and compared with other adjustment structures, reduces the negative mass and improves the thrust-to-mass ratio of the solid rocket motor.

[0021] (2) The present invention adjusts the position of the thickened section of the insulation layer, realizing two common working modes of boost - endurance and boost - acceleration, and improving the strong adaptability, versatility, and interchangeability of solid rocket engines.

[0022] (3) The present invention uses a low - burning - rate propellant grain to replace the thickened section of the insulation layer, achieving an increase in the chamber loading ratio and an improvement in the engine thrust - mass ratio. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0024] Figure 1 It is a sectional view of the charge structure of the boost - endurance engine provided by the present invention;

[0025] Figure 2 It is a sectional view of the charge structure of the boost - acceleration engine provided by the present invention;

[0026] Figure 3 It is a sectional view of the charge structure of the boost - endurance engine with a low - burning - rate propellant grain replacing the head thickened section of the insulation layer provided by the present invention;

[0027] Figure 4 It is a sectional view of the charge structure of the boost - acceleration engine with a low - burning - rate propellant grain replacing the tail thickened section of the insulation layer provided by the present invention;

[0028] Figure 5 It is the thrust curve and working stage of the boost - endurance working mode of a thrust - adjustable charge structure provided by an embodiment of the present invention;

[0029] Figure 6 It is the thrust curve and working stage of the boost - acceleration working mode of a thrust - adjustable charge structure provided by an embodiment of the present invention;

[0030] Figure 7 It is the thrust comparison curve and working stage of the boost - endurance working mode of a thrust - adjustable charge structure using a low - burning - rate propellant grain to replace the head thickened section of the insulation layer provided by an embodiment of the present invention;

[0031] Figure 8 It is the thrust comparison curve and working stage of the boost - acceleration working mode of a thrust - adjustable charge structure using a low - burning - rate propellant grain to replace the tail thickened section of the insulation layer provided by an embodiment of the present invention.

[0032] Reference Signs:

[0033] 1. Combustion chamber shell; 2. Insulation layer of the cylinder section; 3. Insulation layer of the thickened section; 4. Grain; 5. Low burning rate propellant grain. Detailed implementation manners

[0034] To better understand the above technical solution, the technical solution of the present application will be described in detail below through the accompanying drawings and specific embodiments. It should be understood that the embodiments of the present application and the specific features in the embodiments are detailed descriptions of the technical solution of the present application, rather than limitations on the technical solution of the present application. Without conflict, the technical features in the embodiments of the present application and the embodiments can be combined with each other.

[0035] The combustion chamber shell 1 is processed and formed from high-strength alloy steel. The insulation layer 2 of the cylinder section and the insulation layer 3 of the thickened section are processed and formed from ethylene propylene diene monomer (EPDM) rubber, and are bonded to the combustion chamber shell 1 through an adhesive, and then a high burning rate propellant is poured to form the grain 4, specifically as Figures 1 to 2 shown.

[0036] A thrust adjustable charge structure, the structure includes a combustion chamber shell 1, an insulation layer 2 of the cylinder section, a grain 4, and an insulation layer 3 of the thickened section. By changing the position of the insulation layer 3 of the thickened section, the recession burning surface A of the grain is realized by using the thickness of the insulation layer b change, thereby realizing continuous adjustment of the thrust of the solid rocket engine and realizing different working modes;

[0037] The working modes include a boost - endurance working mode and a boost - acceleration working mode;

[0038] The thrust F generated by the thrust adjustable charge structure and the characteristic velocity C* of the propellant, density ρ P , burning rate r, nozzle efficiency C F and burning surface A b The relationship between them is:

[0039] F = C F C * ρ P A b r

[0040] When the propellant (characteristic velocity C*, density ρ P , burning rate r) and the nozzle (nozzle efficiency C F ) are selected, the larger the burning surface A b , the greater the thrust; the smaller the burning surface A b , the smaller the thrust.

[0041] The relationship between the burning surface A b at any time of the thrust adjustable charge structure and the initial burning surface A 0 of the charge, the inner diameter d of the grain, the length L of the grain, and the burning layer thickness e is:

[0042] A b = A 0 + 2π(L - d)e - 3πe 2

[0043] When the length L of the grain and the outer diameter D of the grain satisfy L / D < 1, an approximately steady thrust curve can be obtained.

[0044] As Figure 1 shown, the thickened section insulation layer 3 is located at the head to achieve the boost - endurance working mode. The test - firing thrust curve and the working stages are as Figure 5 shown;

[0045] As Figure 2 shown, the thickened section insulation layer 3 is located at the tail to achieve the boost - acceleration working mode. The simulated thrust curve and the working stages are as Figure 6 shown;

[0046] The adjustable - thrust charge structure uses a low - burning - rate propellant grain 5 to replace the thickened section insulation layer 3. The insulation layer 2 of the cylinder section is bonded to the combustion chamber shell 1 through an adhesive. The low - burning - rate propellant grain replaces the thickened section insulation layer at the head. First, the low - burning - rate propellant is cast to form the low - burning - rate propellant grain 5, and then the high - burning - rate propellant is cast to form the grain 4, as Figure 3 shown; The low - burning - rate propellant grain replaces the thickened section insulation layer at the tail. First, the high - burning - rate propellant is cast to form the grain 4, and then the low - burning - rate propellant is cast to form the low - burning - rate propellant grain 5, as Figure 4 shown.

[0047] The low - burning - rate propellant grain 5 is located at the head to achieve the boost - endurance working mode of the solid rocket motor, Figure 7 which is the thrust comparison curve and the working stages of the boost - endurance working mode using the low - burning - rate propellant grain 5 to replace the thickened section insulation layer 3 at the head;

[0048] The low - burning - rate propellant grain 5 is located at the tail to achieve the boost - acceleration working mode of the solid rocket motor;

[0049] Figure 8 which is the thrust comparison curve and the working stages of the boost - acceleration working mode using the low - burning - rate propellant grain 5 to replace the thickened section insulation layer 3 at the tail; The replacement of the thickened section insulation layer 3 with the low - burning - rate propellant grain 5 also increases the chamber loading ratio. The total impulse of the engine (the integral of thrust with respect to time) has increased compared to the engine with the thickened section insulation layer, and the impulse - mass ratio of the engine has been improved.

[0050] Thus, the adjustable - thrust charge structure provided by the present invention realizes continuous thrust adjustment of the small - scale solid rocket motor, greatly reduces the dead weight, and improves the impulse - mass ratio of the engine.

[0051] Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the technical solution of the present invention all fall within the protection scope of the technical solution of the present invention. The content not described in detail in the specification of the present invention belongs to the well-known technology of those skilled in the art.

Claims

1. A solid rocket engine thrust adjustable charge structure, comprising a combustion chamber shell, a barrel section insulation layer, and a charge column, characterized in that: The thrust adjustable charge structure also includes a thickened section insulation layer, and the thickness of the insulation layer is used to achieve the retreat of the charge column and the combustion surface A. b The change can realize the continuous adjustment of the thrust of the solid rocket engine and achieve different working modes.

2. The solid rocket engine thrust adjustable charge structure according to claim 1, characterized in that: The working modes include a boost-endurance working mode and a boost-acceleration working mode.

3. The solid rocket engine thrust adjustable charge structure according to claim 1, characterized in that: The thickened section of the insulation layer is located at the head to achieve a boost-endurance working mode.

4. The solid rocket engine thrust adjustable charge structure according to claim 1, characterized in that: The thickened section insulation layer is located at the tail portion to achieve a boost-acceleration working mode.

5. The solid rocket engine thrust adjustable charge structure according to claim 1, characterized in that: The thickened insulation layer can be replaced by a low burning rate propellant grain to realize the solid rocket engine's boost-endurance working mode and boost-acceleration working mode.

6. The solid rocket engine thrust adjustable charge structure according to claim 5, characterized in that: The low burning rate propellant grain is located at the head to achieve a boost-endurance working mode.

7. The solid rocket engine thrust adjustable charge structure according to claim 5, characterized in that: The low burning rate propellant grain is located at the tail to achieve a boost-acceleration working mode.

8. The solid rocket engine thrust adjustable charge structure according to claim 1, characterized in that: The combustion chamber shell material is made of high-strength alloy steel.

9. The solid rocket engine thrust adjustable charge structure according to claim 1, characterized in that: The thermal insulation layer material is EPDM rubber, and the powder column material is high burning rate propellant.

10. The solid rocket engine thrust adjustable charge structure according to claim 1, characterized in that: The length L of the drug column and the outer diameter D of the drug column satisfy L / D<1, thereby obtaining a smooth thrust curve.

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