Four-sided pyramid-shaped flow inducer and design method thereof

Abstract

The present application relates to the technical field of spacecraft manufacturing, and discloses a four-sided pyramid-shaped flow director, which comprises a metal framework and a non-metal protective cover, the metal framework comprises a longitudinal plate and a transverse plate, the longitudinal plate and the transverse plate are of the same size, the longitudinal plate and the transverse plate are both isosceles trapezoidal, a first groove is formed in the central axis of the longitudinal plate along the top thereof downwards, a second groove is formed in the central axis of the transverse plate along the bottom thereof upwards, the sum of the lengths of the first groove and the second groove is the height of the longitudinal plate, the longitudinal plate and the transverse plate are inserted into and welded at the intersection of the first groove and the second groove to form a cross-shaped frame, four panels are respectively welded on the inclined end faces of the cross-shaped frame to form inclined surfaces which are suitable for the inner surface of the non-metal protective cover, and the non-metal protective cover covers the panels. The present application further discloses a design method of the four-sided pyramid-shaped flow director. The four-sided pyramid-shaped flow director and the design method thereof can withstand high-temperature gas flow scouring with large load and meet the requirements of continuous missile launching.

Description

Technical Field

[0001] This invention relates to the field of spacecraft manufacturing technology, specifically to a tetrahedral pyramidal flow guide and its design method. Background Technology

[0002] Ground-based fixed launch primarily utilizes launch systems fixed to the ground to launch missiles. This launch method is commonly used for medium- and long-range surface-to-surface missiles and surface-to-air missiles, such as intercontinental ballistic missiles. Ground-based fixed launch devices are generally fixed to the ground. During launch, the high-temperature, high-pressure exhaust gas generated by the missile impacts and damages the launch site. Traditionally, exhaust gas channeling involves pre-constructing a concrete trough within a certain area at the launch site. However, due to the long range and high thrust of medium- and long-range missiles, the concrete trough cannot fully withstand the high-temperature exhaust gas load. After the first missile launch, parts of the concrete trough are damaged by the exhaust gas and must be repaired with concrete before a second launch. The concrete repair process is complex and time-consuming, failing to meet the requirements for continuous missile launches. Therefore, a exhaust gas channeling device capable of withstanding the high-temperature exhaust gas load and enabling continuous launches is necessary. Summary of the Invention

[0003] The purpose of this invention is to address the shortcomings of the aforementioned technologies by providing a four-sided pyramidal flow guide and its design method, which can withstand the scouring of high-temperature gas flow under heavy loads and meet the requirements for continuous missile launches.

[0004] To achieve the above objectives, the tetrahedral conduit designed in this invention includes a metal frame and a non-metallic protective cover. The metal frame includes a vertical plate and a horizontal plate, both of the same size and isosceles trapezoidal in shape. A first groove is formed downwards along the central axis of the vertical plate, and a second groove is formed upwards along the central axis of the horizontal plate. The sum of the lengths of the first and second grooves is the height of the vertical plate. The vertical plate and the horizontal plate are inserted and welded together through the first and second grooves to form a cross frame. A panel is welded to each of the four panels on the inclined end face of the cross frame, forming an inclined surface suitable for the inner surface of the non-metallic protective cover. The non-metallic protective cover covers the panels.

[0005] A design method for the aforementioned tetrahedral pyramidal flow guide includes the following steps:

[0006] A) Design the structural parameters of the diffuser based on the diameter of the engine nozzle exit section, including the diffuser bottom side length L and the diffuser height H. The diffuser bottom side length L must meet the following requirements:

[0007] L = k d d e

[0008] In the formula, k d d is the coefficient for the side length of the bottom surface of the guide vane, taken as 1.2 to 1.5. e The diameter of the engine nozzle exit section;

[0009] The total height H of the flow deflector must meet the following requirements:

[0010] H = k e d e

[0011] In the formula, k e The guide vane height coefficient is taken as 0.7 to 1.0;

[0012] B) Select the non-metallic protective cover material according to the working conditions, including carbon fiber phenolic resin or carbon fiber magnesium phenolic resin, and determine the structural parameters of the non-metallic protective cover, including the head thickness H1, the bevel thickness T, and the transition fillet R between the two bevels of the non-metallic protective cover. The head thickness H1 of the non-metallic protective cover must meet the following requirements:

[0013] H1 = k c ×A×(γ×t)

[0014] In the formula, k c γ is the non-metallic thickness correction factor, ranging from 2 to 3.5; A is the number of times the non-metallic protective cover is used, ranging from 2 to 4 times; γ is the ablation rate, ranging from 0.03 to 0.08 mm / s; and t is the ablation time, ranging from 6 to 12 s.

[0015] The thickness T of the bevel of the non-metallic protective cover must meet the following requirements:

[0016] T = k f ×A×(γ×t)

[0017] In the formula, k f This is the second correction factor for non-metallic thickness, ranging from 1.5 to 2.2;

[0018] The transition fillet radius R is 0.1 to 0.15L;

[0019] C) Select the metal frame material according to the working conditions, including ordinary carbon structural steel or high-strength welded structural steel, with a thickness of 1.5 to 3.5 mm;

[0020] D) Based on the structural parameters of the flow guide, a 3D structural model is created. The structural design quality meets the design input requirements. The rated load is applied to the constructed 3D structural model for simulation analysis and calculation. The simulated maximum stress and maximum deformation of the 3D structural model are calculated, and the corresponding locations of the maximum points are marked. The simulated maximum stress is denoted as σ. 仿max The maximum deformation in the simulation is denoted as A. 仿maxThe safety factor is calculated based on the simulated maximum stress. The formula for calculating the safety factor is as follows:

[0021]

[0022] In the formula, σ s k represents the yield strength of the metal skeleton material. s n is the weld strength coefficient, ranging from 0.7 to 1.0. s For a safety factor not less than 1.5, the maximum simulated deformation is less than 2L‰. If the safety factor n s Simulated Large Deformation A 仿max If the design requirements are met, proceed to the next step; if not, optimize the structural parameters of the guide vane and modify the guide vane side length coefficient k. d , Deflector height coefficient k e Non-metallic thickness correction factor k c Second correction factor for non-metallic thickness k f Until the safety factor n s Simulation of maximum deformation A 仿max Until the design requirements are met;

[0023] E) Satisfies the safety factor n s And the simulated maximum deformation A 仿max After the requirements were met, the structural parameters of the flow guide were finalized. Non-metallic protective covers and metal frames were manufactured according to the finalized parameters. After the non-metallic protective covers were molded, they were fitted onto the welded metal frames. Before fitting them onto the metal frames, a high-temperature erosion resistant coating with adhesive properties was applied to each panel of the metal frames. After curing for 24 hours, the product prototype was assembled.

[0024] Compared with the prior art, the present invention has the following advantages:

[0025] 1. The product meets the requirements for continuous launch, can be used multiple times, and has low maintenance costs;

[0026] 2. The product is surrounded by air channels, which can withstand the high-temperature gas flow of medium and long-range surface-to-surface missiles under heavy loads. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the structure of the tetrahedral pyramidal flow guide of the present invention;

[0028] Figure 2 This is a three-dimensional perspective view of the tetrahedral pyramidal flow guide of the present invention;

[0029] Figure 3 for Figure 2 A schematic diagram of the unfolded metal skeleton;

[0030] Figure 4 for Figure 2A schematic diagram of the unfolded planar structure of the metal skeleton;

[0031] Figure 5 for Figure 4 Schematic diagram of the middle longitudinal plate;

[0032] Figure 6 for Figure 4 A schematic diagram of the middle horizontal plate.

[0033] The components in the diagram are labeled as follows:

[0034] 1. Metal frame; 2. Non-metallic protective cover; 3. Vertical plate; 4. Horizontal plate; 5. First groove; 6. Second groove; 7. Cross frame; 8. Panel. Detailed Implementation

[0035] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0036] like Figure 1 As shown, a four-sided pyramidal flow guide includes a metal frame 1 and a non-metallic protective cover 2. The metal frame 1 includes a vertical plate 3 and a horizontal plate 4. The vertical plate 3 and the horizontal plate 4 are the same size and are both isosceles trapezoidal in shape. The vertical plate 3 has a first groove 5 extending downward from the top along its central axis, and the horizontal plate 4 has a second groove 6 extending upward from the bottom along its central axis. The sum of the lengths of the first groove 5 and the second groove 6 is the height of the vertical plate 3. The vertical plate 3 and the horizontal plate 4 are inserted and welded together through the first groove 5 and the second groove 6 to form a cross frame 7. A panel 8 is welded to the inclined end face of the cross frame 7, and a total of four panels 8 form an inclined surface that is suitable for the inner surface of the non-metallic protective cover 2. The non-metallic protective cover 2 covers the panel 8.

[0037] The design method of the tetrahedral pyramidal flow guide in this embodiment includes the following steps:

[0038] A) Design the structural parameters of the diffuser based on the diameter of the engine nozzle exit section, including the diffuser bottom side length L and the diffuser height H. The diffuser bottom side length L must meet the following requirements:

[0039] L = k d d e

[0040] In the formula, k d d is the coefficient for the side length of the bottom surface of the guide vane, taken as 1.2 to 1.5. e The diameter of the engine nozzle exit section;

[0041] The total height H of the flow deflector must meet the following requirements:

[0042] H = k e d e

[0043] In the formula, k e The guide vane height coefficient is taken as 0.7 to 1.0;

[0044] B. Select the material for the non-metallic protective cover 2 according to the operating conditions, including carbon fiber phenolic resin or carbon fiber magnesium phenolic resin. For medium and long-range surface-to-surface missiles with large payload requirements, carbon fiber magnesium phenolic resin with good impact resistance is generally selected for compression molding. Determine the structural parameters of the non-metallic protective cover 2, including the head thickness H1, the bevel thickness T, and the transition fillet R between the two bevels of the non-metallic protective cover 2. The head thickness H1 of the non-metallic protective cover 2 must meet the following requirements:

[0045] H1 = k c ×A×(γ×t)

[0046] In the formula, k c γ is the non-metallic thickness correction factor, ranging from 2 to 3.5; A is the number of times the non-metallic protective cover 2 is used, ranging from 2 to 4 times; γ is the ablation rate, ranging from 0.03 to 0.08 mm / s; and t is the ablation time, ranging from 6 to 12 s.

[0047] The thickness T of the bevel of the non-metallic protective cover 2 must meet the following requirements:

[0048] T = k f ×A×(γ×t)

[0049] In the formula, k f This is the second correction factor for non-metallic thickness, ranging from 1.5 to 2.2;

[0050] The transition fillet radius R is 0.1 to 0.15L;

[0051] C) Select the material of the metal frame 1 according to the working conditions, including ordinary carbon structural steel or high-strength welded structural steel. For medium and long-range surface-to-surface missiles with large load requirements, high-strength welded structural steel with good strength performance is generally selected and welded into shape with a thickness of 1.5 to 3.5 mm.

[0052] D) Based on the structural parameters of the flow guide, a 3D structural model is created. The structural design quality meets the design input requirements. The rated load is applied to the constructed 3D structural model for simulation analysis and calculation. The simulated maximum stress and maximum deformation of the 3D structural model are calculated, and the corresponding locations of the maximum points are marked. The simulated maximum stress is denoted as σ. 仿max The maximum deformation in the simulation is denoted as A. 仿max The safety factor is calculated based on the simulated maximum stress. The formula for calculating the safety factor is as follows:

[0053]

[0054] In the formula, σ sk represents the yield strength of the metal skeleton material. s n is the weld strength coefficient, ranging from 0.7 to 1.0. s For a safety factor not less than 1.5, the maximum simulated deformation is less than 2L‰. If the safety factor n s Simulated Large Deformation A 仿max If the design requirements are met, proceed to the next step; if not, optimize the structural parameters of the guide vane and modify the guide vane side length coefficient k. d , Deflector height coefficient k e Non-metallic thickness correction factor k c Second correction factor for non-metallic thickness k f Until the safety factor n s Simulation of maximum deformation A 仿max Until the design requirements are met;

[0055] E) Satisfies the safety factor n s And the simulated maximum deformation A 仿max After the requirements were met, the structural parameters of the flow guide were finalized. Non-metallic protective cover 2 and metal frame 1 were manufactured according to the finalized parameters. After the non-metallic protective cover 2 was molded, it was fitted onto the welded metal frame 1. Before fitting it onto the metal frame 1, a high-temperature erosion resistant coating with adhesive properties was applied to each panel of the metal frame 1. After curing for 24 hours, the product prototype was assembled.

[0056] The present invention relates to a four-sided pyramidal guide and its design method. The product meets the requirements for continuous launch, can be used multiple times, and has low maintenance costs. The product has a four-sided guide and can withstand the high-temperature gas flow scouring of medium and long-range surface-to-surface missiles with large loads.

Claims

1. A tetrahedral pyramidal flow guide, comprising a metal frame (1) and a non-metallic protective cover (2), characterized in that: The metal frame (1) includes a vertical plate (3) and a horizontal plate (4). The vertical plate (3) and the horizontal plate (4) are the same size. Both the vertical plate (3) and the horizontal plate (4) are isosceles trapezoidal in shape. The vertical plate (3) has a first groove (5) extending downward from the top along its central axis. The horizontal plate (4) has a second groove (6) extending upward from the bottom along its central axis. The sum of the lengths of the first groove (5) and the second groove (6) is the height of the vertical plate (3). The vertical plate (3) and the horizontal plate (4) are inserted and welded together through the first groove (5) and the second groove (6) to form a cross frame (7). A panel (8) is welded to the inclined end face of the cross frame (7). A total of four panels (8) form an inclined surface that is suitable for the inner surface of the non-metallic protective cover (2). The non-metallic protective cover (2) covers the panels (8). The design method of the four-sided pyramidal guide includes the following steps: A) Design the structural parameters of the guide vane based on the diameter of the engine nozzle exit section, including the guide vane bottom side length L and the guide vane height H. The guide vane bottom side length L must meet the following requirements: In the formula, The coefficient for the side length of the bottom surface of the guide vane is taken as 1.2 to 1.

5. The diameter of the engine nozzle exit section; The total height H of the flow deflector must meet the following requirements: In the formula, The guide vane height coefficient is taken as 0.7 to 1.0; B) Select the material of the non-metallic protective cover (2) according to the working conditions, including carbon fiber phenolic resin or carbon fiber magnesium phenolic resin, and determine the structural parameters of the non-metallic protective cover (2), including the head thickness H1 of the non-metallic protective cover (2), the bevel thickness T of the non-metallic protective cover (2), and the transition fillet R between the two bevels of the non-metallic protective cover (2). The head thickness H1 of the non-metallic protective cover (2) meets the following requirements: H1= ×A×(γ×t) In the formula, γ is the non-metallic thickness correction coefficient, which is 2 to 3.5; A is the number of times the non-metallic protective cover (2) is used, which is 2 to 4 times; γ is the ablation rate, which is 0.03 to 0.08 mm / s; t is the ablation time, which is 6 to 12 s. The thickness T of the bevel of the non-metallic protective cover (2) must meet the following requirements: T= ×A×(γ×t) In the formula, This is the second correction factor for non-metallic thickness, ranging from 1.5 to 2.2; The transition fillet radius R is 0.1 to 0.15L; C) Select the metal frame (1) material according to the working conditions, including ordinary carbon structural steel or high-strength welded structural steel, with a thickness of 1.5 to 3.5 mm; D) Based on the structural parameters of the flow guide, a 3D structural model is created. The structural design quality meets the design input requirements. The rated load is applied to the constructed 3D structural model for simulation analysis and calculation. The simulated maximum stress and maximum deformation of the 3D structural model are calculated, and the corresponding locations of the maximum points are marked. The simulated maximum stress is denoted as... 仿max The maximum deformation in the simulation is denoted as A. 仿max The safety factor is calculated based on the simulated maximum stress. The formula for calculating the safety factor is as follows: In the formula, The yield strength of the metal skeleton material. The weld strength coefficient is taken as 0.7 to 1.

0. For a safety factor not less than 1.5, the maximum simulated deformation should be less than 2L‰. Simulated Large Deformation A 仿max If the design requirements are met, proceed to the next step; if not, optimize the structural parameters of the guide vane and modify its side length coefficient. Deflector height coefficient Non-metallic thickness correction factor Second correction factor for non-metallic thickness Until the safety factor Simulation of maximum deformation A 仿max Until the design requirements are met; E) Satisfies the safety factor And the simulated maximum deformation A 仿max After the requirements are met, the structural parameters of the flow guide are finalized. Non-metallic protective cover (2) and metal frame (1) are manufactured according to the finalized parameters. After the non-metallic protective cover (2) is molded, it is fitted onto the welded metal frame (1). Before fitting, a high-temperature erosion resistant coating with adhesive properties is applied to each panel of the metal frame (1). After curing for 24 hours, the product prototype is assembled.

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