Tail Design And Aerodynamic Analysis Of A Special Shaped Projectile

The thrown trajectory stability is rarely studied in China.More attention is paid to the bullet dispersion and the influence on the accuracy of the bullet.The bullet ballistic stability is of great significance for the bullet fuse release and the bullet end damage.In order to ensure the flight stability of the bullet after separation from the projectile and to achieve the predetermined operational effect,it is necessary to carry out in-depth research on the effect of the bullet tail.In this paper,based on the combination of theoretical analysis and numerical simulation,the different designs of the tail fins are systematically studied.The different opening angles of the fins and the different fin shapes are used to pneumatically control the projectile.The influence of the characteristics determines the final selection of the shaped projectile tail design according to engineering background..The main research work and results of this paper are as follows:1.The action process,function principle and assembly state of the bullet are described.The tail fins with different wing opening angles and different wing shapes are designed for the shaped projectiles with the cross-section being approximately trapezoidal.2.The theoretical model and calculation method for the calculation of aerodynamic parameters during the flight of the projectile are given.The flow field of the projectile under different angles of attack is simulated by Fluent software.The simulation results are used to fit the projectile.The lift coefficient curve,the drag coefficient curve,the pitching moment coefficient curve,and the surface pressure cloud map and velocity streamline diagram of the projectile during flight;the influences of different opening angles of the fins on the aerodynamic characteristics of the projectile and the different opening angles of the fins are obtained.The influence of the shape of the fin on the aerodynamic characteristics of the projectile.3.The appropriate six-degree-of-freedom external ballistic model of projectile flight is established.The aerodynamic parameters calculated by Fluent are substituted into the model,and the external ballistic simulation is carried out by Matlab/Simulink software.The angle of attack,height and stroke of the projectile are obtained with time.The law of change.4.Analyze the stability conditions of the projectile,comprehensively consider the flight stability of the projectiles with five different tail designs,and determine the final selection of the design of the shaped projectile tails in accordance with the stability of Lyapunov.The main purpose of this paper is to enable the archery design workers to have certainpredictive ability for the stability of the designed projectiles at the beginning of the design,and to provide reference for the bullet scattering and precision design and the evaluation of the submunition’s combat effectiveness.