Solid charge for implementing large-thrust constant-area combustion and manufacturing process thereof

Abstract

The application discloses a solid charge for realizing large-thrust constant-face combustion and a manufacturing process thereof, and belongs to the field of solid rocket engines, comprising a grain, an axial rear end and a rear end face of the grain are provided with a cladding layer, at least one slot distributed along the axial direction is formed in the cladding layer, an axial front end of the slot is communicated with an axial front end of the grain, and a surface of the grain without the cladding layer is a combustion face, different thrust requirements can be met by changing the area of the cladding layer and the area of the slot, a constant-thrust movement law of the combustion face is achieved, a missile can be kept working at constant large thrust, in addition, the solid charge structure has a large charge amount, the range of the missile is improved, and the technical problem that constant large thrust cannot be realized while the charge amount is ensured in the prior art is solved.

Description

Technical Field

[0001] This invention belongs to the field of solid rocket engines and relates to propellant structure, specifically a solid propellant for achieving high-thrust constant-surface combustion and its manufacturing process. Background Technology

[0002] For small tactical missiles, to improve their accuracy, higher missile operating speeds are required, necessitating engines that provide constant, high thrust. To extend missile range, the propellant charge must be maximized, and the operating time extended. In the field of solid rocket motors, the propellant morphology directly determines the missile's operating parameters; the propellant charge represents the missile's flight range; the size of the burning surface determines the missile's thrust; and changes in the burning surface reflect the missile's flight trajectory. Therefore, propellant morphology design is a core component of solid rocket motor design. Solid propellant structures with bonded casings offer the largest propellant charge, but due to structural limitations, this morphology can only achieve constant, low thrust. Perforated propellant structures with bonded casings provide greater constant thrust, but in high aspect ratio engines, sufficient gas flow channels must be reserved to prevent erosion combustion, resulting in significant propellant charge loss. To achieve the requirement of constant, high thrust while also considering the goal of large propellant charge, novel propellant structures need to be designed and developed. Summary of the Invention

[0003] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a solid charge for achieving high thrust constant surface combustion and its manufacturing process, so as to solve the technical problem that the existing technology cannot achieve constant high thrust while ensuring the amount of charge.

[0004] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0005] A solid charge for achieving high-thrust constant-surface combustion includes a propellant grain, wherein the axial rear end and the rear end face of the propellant grain are provided with a coating layer, and at least one groove distributed along the axial direction is formed on the coating layer, wherein the axial front end of the groove is connected to the axial front end of the propellant grain.

[0006] This invention also includes the following technical features:

[0007] The coating layer is made of EPDM rubber.

[0008] The groove is a rectangular groove.

[0009] The area of ​​the drug column without a coating layer Satisfy the following formula:

[0010]

[0011] in:

[0012] This represents the area of ​​the front end face of the propellant column, in mm. 2 ;

[0013] This represents the area of ​​the cylindrical surface at the tip of the propellant column without a coating layer, in mm. 2 ;

[0014] Indicates the area of ​​the groove, in mm. 2 ;

[0015] Indicates the diameter of the propellant column, in mm;

[0016] Indicates the length of the propellant column, in mm;

[0017] This indicates the length of the cylindrical surface at the tip of the propellant column without a coating layer, in mm;

[0018] Indicates the length of the groove, in mm;

[0019] Indicates the width of the groove, in mm;

[0020] Indicates the number of slots.

[0021] The length of the cylindrical surface at the front end of the bolus without a coating layer Length of the medicine column The ratio ranges from 1 / 4 to 1 / 2, and the number of slots n is 2.

[0022] A manufacturing process for a solid charge used to achieve high-thrust constant-plane combustion, based on the solid charge used to achieve high-thrust constant-plane combustion, includes the following steps:

[0023] Step 1: Pour the propellant slurry into the pre-made coating layer;

[0024] Step 2: After the propellant slurry has solidified and formed, the propellant grains and coating layers are structurally shaped according to the design requirements.

[0025] The structural shaping involves removing the coating layer located at the axial front end of the propellant column and opening at least one groove at the axial rear end of the propellant column.

[0026] Compared with the prior art, the beneficial technical effects of this invention are:

[0027] In this invention, the surface of the propellant grain without a coating layer is the combustion surface. By changing the area of ​​the coating layer and the area of ​​the groove, different thrust requirements can be met to achieve a constant displacement law of the combustion surface, so that the missile can maintain a constant high thrust. In addition, the solid charge structure has a large charge volume, which increases the missile range and solves the technical problem in the prior art that it is impossible to achieve a constant high thrust while ensuring the charge volume. Attached Figure Description

[0028] Figure 1 This is a three-dimensional structural diagram of the present invention;

[0029] Figure 2 This is a cross-sectional schematic diagram of the present invention.

[0030] The labels in the diagram represent: 1. Medicinal material, 2. Coating layer, 3. Groove.

[0031] The specific content of the present invention will be further explained in detail below with reference to the embodiments. Detailed Implementation

[0032] It should be noted that, unless otherwise specified, all components in this invention are those known in the art.

[0033] The following are specific embodiments of the present invention. It should be noted that the present invention is not limited to the following specific embodiments. All equivalent modifications made based on the technical solutions of this application fall within the protection scope of the present invention.

[0034] The present invention provides a solid charge for achieving high-thrust constant-surface combustion, comprising a propellant charge 1, wherein the axial rear end and the rear end face of the propellant charge 1 are provided with a coating layer 2, and at least one groove 3 distributed along the axial direction is formed on the coating layer 2, and the axial front end of the groove 3 is connected to the axial front end of the propellant charge 1.

[0035] In the above technical solution, opening the groove 3 can increase the initial burning surface and make the burning surface increase in size during the pushing process. The outer side of the first half of the propellant 1 has no coating layer 2. During the pushing process, the burning surface area gradually decreases. The groove 3 opened in the second half of the propellant 1 makes the burning surface area gradually increase during the pushing process. By adjusting the design parameters such as the axial length of the coating layer 2 and the width, length and number of the groove 3, the burning surface of the entire propellant can be made to have constant surface size during the pushing process.

[0036] Specifically, the covering layer 2 is made of EPDM rubber.

[0037] Specifically, slot 3 is a rectangular slot.

[0038] In the above technical solution, setting the groove 3 as a rectangle is beneficial for determining the size of the combustion surface, which makes it possible to determine the thrust more accurately.

[0039] The area of ​​the propellant column 1 without the coating layer 2 Satisfy the following formula:

[0040]

[0041] in:

[0042] This represents the area of ​​the front end face of propellant column 1, in mm. 2 ;

[0043] This represents the area of ​​the cylindrical surface at the tip of the propellant grain 1 without the coating layer 2, in mm. 2 ;

[0044] This indicates the area of ​​slot 3, in mm. 2 ;

[0045] Indicates the diameter of propellant column 1, in mm;

[0046] Indicates the length of charge 1, in mm;

[0047] The length, in mm, of the cylindrical surface at the front end of the propellant grain 1 without the coating layer 2.

[0048] Indicates the length of slot 3, in mm;

[0049] Indicates the width of slot 3, in mm;

[0050] This indicates the number of slots 3.

[0051] The length of the cylindrical surface at the front end of the propellant column 1 without the coating layer 2 Length of pharmacopoeia 1 The ratio ranges from 1 / 4 to 1 / 2, and the number of slots 3, n, is 2.

[0052] A manufacturing process for a solid charge used to achieve high-thrust constant-plane combustion is also provided, which includes the following steps:

[0053] Step 1: Pour the propellant slurry into the pre-made coating layer 2;

[0054] Step 2: After the propellant slurry has solidified and formed, the propellant column 1 and the coating layer 2 are structurally shaped according to the design requirements;

[0055] The structural shaping involves removing the coating layer 2 located at the axial front end of the propellant grain 1 and opening at least one groove 3 at the axial rear end of the propellant grain 1.

[0056] Example 1: Under a constant thrust T requirement, the propellant charge of the present invention is 573g, the propellant thickness is 14.8mm, and the engine operating time is 2.11s.

[0057] Comparative Example 1: Under a constant thrust T requirement, the explosive charge of the star-shaped hole charge is 516g, the explosive charge thickness is 10.2mm, and the engine operating time is 1.46s.

[0058] The star-shaped propellant charge is a common type of constant-surface propellant charge used to achieve high thrust with a large aspect ratio. It involves perforating the center of a solid propellant grain with a star-shaped structure to increase the burning surface. Compared to the star-shaped propellant charge, this invention, based on a solid propellant grain, exposes a portion of the propellant surface by bonding a coating layer to the outer surface of the charge, forming an initial burning surface and achieving constant high thrust output.

[0059] Comparing Example 1 and Comparative Example 1, it was found that both propellant types can provide constant high thrust within the same space. However, compared to the star-shaped propellant structure, the star-shaped propellant structure of this invention has a propellant charge of 90% of that of this invention, and provides 69% of the engine's operating time. This invention has a higher loading coefficient, a larger propellant charge, and can provide the engine with a longer operating time.

[0060] Example 2: In the same space, with the same charge M, this charge can provide 608N of thrust;

[0061] Comparative Example 2: In the same space, with the same charge M, the end-burning propellant can provide 20N of thrust;

[0062] End-burning propellant types are propellant types in which the outer surface and front end face of the charge are covered, leaving only the rear end face as the burning surface. End-burning propellant types have a high loading coefficient and can achieve constant thrust output for a long time. However, their disadvantage is that due to the limitation of the charge diameter, the area of ​​the charge end face is limited, resulting in a smaller thrust of the charge.

[0063] Comparing Example 2 and Comparative Example 2, it was found that the thrust provided by the present invention is 30 times that of the end-burning propellant type.

[0064] Example 3:

[0065] This embodiment provides a manufacturing process for solid propellant to achieve high-thrust constant-surface combustion, specifically including the following steps:

[0066] Step 1: Pour the propellant slurry into the pre-made coating layer 2;

[0067] Step 2: After the propellant slurry has solidified and formed, the propellant column 1 and the coating layer 2 are structurally shaped according to the design requirements;

[0068] The design requirement is: an average engine thrust of 790 N.

[0069] The structural shaping is as follows: the total length of the coating layer 2 is 480mm. The coating layer 2 with a length of 156mm located on the axial front end sidewall of the propellant grain 1 is removed. Then, two grooves 3 with a width of 8mm and a length of 324mm are opened on the axial rear end sidewall of the propellant grain 1.

[0070] Therefore, the initial ignition surface of the charge in this embodiment is 20378 mm. 2 The area of ​​the front end face is 688 mm. 2 The uncovered length of the front end of propellant charge 1 is 156 mm, the radius of propellant charge 1 is 14.8 mm, and the corresponding initial burning surface is 14506 mm. 2 The rear end of the propellant column 1 has two grooves of equal width, each 8 mm wide and 324 mm long, corresponding to an initial ignition surface of 5184 mm. 2 The front-to-rear fuel surface ratio is 2.93:1;

[0071] During the burning process, the burning surface at the front end of charge 1 gradually decreases, while the burning surface at the rear end gradually increases. When half of the charge thickness is burned away, the burning surface of charge 1 is 22356 mm. 2 (Increasing the initial burning surface by 9.7%), the burning surface at the tip of the charge is now 7644 mm. 2 The burning surface formed by the slot at the rear end of the charge is 14712 mm. 2 The front-to-rear fuel surface ratio is 1:1.92;

[0072] Just before the thickest part of the explosive charge was completely burned, the burning surface of the charge was 19566 mm. 2 (Reduced by 4.0% from the initial burning surface), at this point, the burning surface at the tip of the charge is 690 mm. 2 The combustion surface formed by the slot at the rear end of the charge is 18876 mm. 2 The front-to-rear fuel surface ratio is 1:27.36.

[0073] During the combustion process described above, the burning surface of the propellant exhibits constant surface properties, and the engine achieves an average thrust of 790 N.

[0074] It should be noted that the initial burning surface of the propellant is the pre-set burning surface area of ​​the propellant 1 before it burns, including the area of ​​the front end face of the propellant 1, the area of ​​the front end of the propellant 1 that is not covered, and the area of ​​the upper groove 3 at the axial rear end of the propellant 1.

Claims

1. A solid charge for implementing large-thrust constant-area combustion, comprising a grain (1), characterized in that, The axial rear end and rear end face of the propellant grain (1) are provided with a coating layer (2), and at least one slot (3) is formed in the coating layer (2) and distributed along the axial direction, and the axial front end of the slot (3) is communicated with the axial front end of the propellant grain (1); The length of the cylindrical surface at the front end of the drug column (1) without the coating layer (2) Length of the drug column (1) The ratio ranges from 1 / 4 to 1 / 2, and the number n of slots (3) is 2. The area of the drug column (1) without the coating layer (2) satisfies the following formula: Wherein: represents the area of the front end face of the cartridge (1), mm 2 ; represents the area of the cylindrical surface of the front end of the cartridge (1) on which the covering layer (2) is not provided, mm 2 ; represents the area of the groove (3), mm 2 ; D represents the diameter of the propellant charge (1), mm; L represents the length of the cartridge (1), mm; L - length of the cylindrical surface of the front end of the propellant grain (1) without the coating (2), mm; represents the length of the slot (3), mm; represents the width of the slot (3), mm; represents the number of slots (3).

2. The solid charge for achieving a large-thrust constant-area combustion of claim 1, wherein, The coating layer (2) is made of ethylene-propylene-diene rubber.

3. The solid charge for achieving a large-thrust constant-face combustion of claim 1, wherein The slot (3) is a rectangular slot.

4. A manufacturing process for a solid charge for implementing large-thrust constant-area combustion, characterized in that, The solid charge for realizing large-thrust constant-area combustion according to any one of claims 1-3 comprises the following steps: Step one, pouring propellant slurry into the prefabricated coating layer (2); Step two, after the propellant slurry is solidified and formed, the propellant grain (1) and the coating layer (2) are structurally shaped according to design requirements; The structural shaping is to remove the coating layer (2) located at the axial front end of the propellant grain (1), and to form at least one slot (3) at the axial rear end of the propellant grain (1).

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