The stern structure suitable for the tail section of the tail bomb
By setting up a drag reduction groove in the middle of the tail section of the tail of the tail wing bullet, the problem of large bottom resistance caused by the complex flow field of the bottom of the tail wing bullet is solved, and the range is improved.
Patent Information
- Application Number
- CN202510157682.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2024-11-12
- Filing Date
- 2025-02-13
- Publication Date
- 2025-04-04
AI Technical Summary
The flow field at the bottom of the projectile of the tail bullet is complex, resulting in deterioration of the vortex structure and large bottom resistance, affecting the range.
A drag reduction groove along the length of the spring body is set up in the middle of the tail section of the tail wing, and the depth of the drag reduction groove deepens with the advancement towards the tail of the spring. The width is reduced first to between the tail wings and then increased to the tail of the spring, with a slope of 5-8°.
It effectively reduces the cross-sectional area of the bottom of the projectile, weakens the flow field distortion and vortex structure strength, significantly reduces the bottom resistance of the tail bullet, and improves the range of the projectile.
Smart Images
Figure CN119756087A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a stern structure, in particular to a stern structure suitable for the tail section of a tail fin missile body, and belongs to the technical field of drag reduction and range increase of tail fin missiles. Background Art
[0002] The aerodynamic performance of ammunition is one of the most important parameters for the formation of artillery ammunition. Especially for the more complex tail-fin projectiles among rotating projectiles, the aerodynamic forces they are subjected to are also relatively complex, and the work of reducing drag and increasing range of tail-fin projectiles is also relatively complex.
[0003] The main aerodynamic resistances encountered by the projectile include the following three aspects: wave resistance generated by the projectile, friction resistance caused by the viscous friction of the air in the projectile flow field, and bottom resistance caused by the low-pressure area of the vortex caused by the separation of the airflow at the bottom of the projectile.
[0004] Among them, the bottom drag accounts for 50% of the projectile resistance in transonic flight and 35% in supersonic flight. It can be seen that reducing the bottom drag is an effective way to reduce the resistance of the tail-fin projectile and increase the range of the tail-fin projectile.
[0005] The tail fin projectile has to design and install tail fins at the end of the projectile, and the structure is relatively complex; the flow field at the bottom of the projectile of the tail fin projectile is more complicated, the vortex structure is worsened, and the bottom resistance of the projectile is therefore greater, and the resulting range loss cannot be ignored.
[0006] Therefore, improvements are needed to meet the complex requirements of reducing the base resistance and increasing the range of tail-fin bullets without affecting the normal working performance of the tail fins at the terminal end of the projectile. Summary of the invention
[0007] In order to solve the deficiencies of the prior art, the object of the present invention is to provide a stern structure suitable for the tail section of a tail bomb body.
[0008] In order to achieve the above object, the present invention adopts the following technical solution:
[0009] A stern structure of the tail section of the missile body, wherein a drag reduction groove is provided between the tail fins of the tail section of the missile body along the length direction of the missile body;
[0010] The depth of the drag reduction groove increases as it moves toward the tail of the projectile;
[0011] The width of the drag reduction groove decreases as it moves toward the tail of the projectile, and after decreasing to between the tail wings, it gradually increases to the tail of the projectile.
[0012] The slope of the above-mentioned drag reduction groove is 5-8°.
[0013] Furthermore, the slope of the drag reduction groove is 7°.
[0014] The starting position of the above-mentioned drag reduction groove is 1-1.5 times the wing root chord length in front of the leading edge of the tail wing root.
[0015] Furthermore, the starting position of the above-mentioned drag reduction groove is 1.2 times the wing root chord length in front of the leading edge of the tail wing root.
[0016] The present invention is beneficial in that:
[0017] The stern structure of the present invention is suitable for the tail section of the tail fin projectile body. The drag reduction groove is arranged between the tail fins, and the depth and width of the drag reduction groove gradually change along the length direction, wherein the depth gradually decreases from the starting end to the tail of the projectile, and the groove depth is sloped; the width first decreases to between the tail fins and then increases to the tail of the projectile. It effectively reduces the cross-sectional area of the bottom of the projectile, reduces the degree of flow field distortion in this area, reduces the vortex structure strength in this area, reduces the tail fin projectile bottom resistance, and increases the projectile range.
[0018] The stern structure of the present invention, which is suitable for the tail section of the tail fin projectile, is improved in design without affecting the normal operation of the original tail fin of the structure section. It can not only greatly improve the projectile range, but also has higher economy than the current tail fin projectile, and has strong practicality and wide applicability. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 This is a schematic diagram of the stern structure.
[0020] The meanings of the marks in the accompanying drawings are as follows: 1. drag reduction groove, 2. tail wing. DETAILED DESCRIPTION
[0021] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.
[0022] The invention is applicable to the stern structure of the tail section of the missile body of a tail fin bomb, and a drag reduction groove is arranged between the tail fins of the tail section of the missile body along the length direction of the missile body.
[0023] The starting position of the drag reduction groove is 1-1.5 times the wing root chord length before the leading edge of the tail wing root, preferably 1.2 times the wing root chord length. The depth of the starting position is 0.
[0024] As the projectile moves toward the tail, the depth of the drag reduction groove gradually increases, and the amount of deepening is measured by the slope, which is 5-8°, preferably 7°.
[0025] The width of the drag reduction groove decreases as it moves toward the tail of the missile, and after decreasing to between the tail fins, it gradually increases to the tail of the missile.
[0026] Take a certain 76mm standard tail-fin bomb with 8 tail fins as an example.
[0027] There are 8 drag reduction grooves distributed between the 8 tail wings.
[0028] The axial length of the stern structure is 92mm, and the starting position is 1.2 times the wing root chord length in front of the leading edge of the tail wing root.
[0029] The slope of the drag reduction groove is 7°.
[0030] The maximum depth of the drag reduction groove is 12mm at the bottom of the missile, and the maximum width is 24mm at the start of the stern structure.
[0031] Without affecting the normal operation of the tail fin, the stern structure (drag reduction groove) distributed between the tail fins effectively reduces the cross-sectional area of the bottom of the projectile and the degree of flow field distortion in this area. The vortex structure at the bottom of the projectile is significantly weakened and the bottom resistance is significantly reduced.
[0032] After numerical simulation calculations and scaled model wind tunnel test verification of a certain type of 76mm tail fin projectile using different stern angles of 0-10° of the present invention, it was found that at a stern angle of 7°, the drag of the standard tail fin projectile in the supersonic section was reduced by 2.5-7%, and in the subsonic section, the drag reduction groove formed a flow field expansion section structure, which increased the flow velocity in this area, and the flow field condition at the bottom of the projectile was further improved, and its drag was reduced by more than 15%.
[0033] The relevant data are shown in the following table.
[0034] Tail fin drag at different stern angles at 2 Ma
[0035] Stern angle / ° 0 5 6 7 8 9 10 Resistance / N 760 735 732 723 725 726 728
[0036] Drag of a 7° stern-angle fin projectile at different Mach numbers
[0037] Mach number 0.6 0.8 1.2 1.5 2 2.65 No stern angle resistance / N 537 575 1030 928 760 600 With stern angle resistance / N 435 477 954 871 723 583 Drag reduction rate / % 19 17 7.4 6.1 4.9 2.8
[0038] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the above embodiments do not limit the present invention in any form, and any technical solution obtained by equivalent replacement or equivalent transformation falls within the protection scope of the present invention.
Claims
1. A stern structure suitable for the tail section of a tail fin missile, characterized in that: A drag reduction groove is provided between the tail fins at the tail section of the missile body along the length direction of the missile body; The depth of the drag reduction groove increases as it moves toward the tail of the projectile; The width of the drag reduction groove decreases as it moves toward the tail of the projectile, and after decreasing to between the tail wings, it gradually increases to the tail of the projectile.
2. The structure according to claim 1, characterized in that: The slope of the drag reduction groove is 5-8°.
3. The structure according to claim 2, characterized in that: The slope of the drag reduction groove is 7°.
4. The structure according to claim 1, characterized in that The starting position of the drag reduction groove is 1-1.5 times the wing root chord length before the leading edge of the tail wing root.
5. The structure according to claim 4, characterized in that: The starting position of the drag reduction groove is 1.2 times the wing root chord length in front of the leading edge of the tail wing root.