Aerodynamic Characteristics And External Ballistics Analysis Of The Air Rocket

The air rockets are non-guided munitions that equipped on fighter or armed helicopters which powered by solid rocket engine.It takes the air rocket as the research object to analyzed the Aerodynamic characteristics.under the conditions of no rotation and rotation by means of numerical simulation.And the aerodynamic parameters were obtained.Then,a Monte Carlo method was used to simulate the shooting,and the rocket launchers scattered under random disturbance factors was analyzed.Details are as follows:The physical model of the air rocket was simplified and simulated by Fluent.Researching the outflow field of with and without angle of attack to analyze the aerodynamic characteristics and the influence of angle of attack to outflow field.The aerodynamic parameters of rockets were analyzed with the Mach number and the angle of attack.Then,comparison of CFD results and wind tunnel data indicated the simulation method was credible.The results showed that the drag coefficient of rocket firstly increased and then decreased with the increase of Mach number,which was consistent with the laws of aerodynamics.Simulating the steady rotation of the rocket by using MRF model.The effect of rotation speed,Mach number and attack angle on roll-damping moment was studied.The balance speed of the projectile was studied in the same way,and the drag characteristics of at balance speed were analyzed.The results showed that the rolling-damping moment cofficient was increased linearly by rotation speed.The roll damping coefficient decreased with the increase of the Mach number.As the angle of attack increased,the roll damping coefficient increased.The balance rotation speed increased linearly with the increase of Mach number.As the angle of attack increased,the rocket balance speed slightly decreased.The drag coefficient which at balance speed firstly increased and then decreased with the increase of Mach number.And the angle of attack has little effect on the rocket resistance coefficient at equilibrium speedThe equations of the air rocket motion were built.The force and moments which the air rocket suffered were studied.And the random disturbance factor which the air rocket sufferd were introduced.Then,using the Monte Carlo method to research the distribution of the air rocket which launched from the ground,helicopter and fighter.The results indicated that CEP decreased with the increase of shooting angle,as the launch altitude increased,CEP increased significantly.And there was no direct correlation between CEP and launch velocity.