固定鸭舵修正弹非线性与非定常气动数值模拟

Simulation on Nonlinear and Unsteady Aerodynamic Characteristics of Fixed-canard Correction Projectile

为准确获得某固定鸭舵修正弹的气动特性,利用CFD数值计算方法对该弹的流场进行数值模拟,采用密度基隐格式与滑移网格技术,计算弹丸在静态、转动和慢圆运动下各项力和力矩的气动系数。仿真结果表明:该弹的升力系数与俯仰力矩系数的非线性气动特性与一般旋转稳定弹不同,俯仰力矩系数非线性项在亚声速区域为正值,超声速区域为负值;该弹修正组件所受导转力矩系数在跨声速段随攻角的变化较为剧烈,在非跨声速段的变化较为平缓;全弹的升力和俯仰力矩与修正组件滚转角、全弹进动角和进动速率都有关。

To accurately obtain the aerodynamic characteristics of a fixed-canard correction projectile,the computational fluid dynamics(CFD)numerical method was used to simulate the flow field of the projectile.The density-based implicit scheme and sliding mesh technique were used to calculate the aerodynamic coefficients of forces and moments of projectiles under the conditions of static,rotational and slow circular motions.The simulation results show that the nonlinear aerodynamic characteristics of lift coefficient and pitch moment coefficient of the projectile are different from those of the general spinning stabilized projectile.The nonlinear terms of pitching moment coefficient is positive in the subsonic region and negative in the supersonic region.The variation of the guided torque coefficient of the projectile correction component with the angle of yaw is intense in the transonic region,but gentle in the non-transonic region.The lift force and pitching moment of the whole projectile are related to the roll angle,the precession angle and the precession velocity.