基于双向流固耦合的机载导弹分离动力学研究

NUMERICAL INVESTIGATIONS ON MISSILE SEPARATION OF AN AIRCRAFT BASED ON CFD/CSD TWO-WAY COUPLING METHOD

导弹与载机之间的安全与稳定分离过程对导弹飞行稳定性和载机安全具有非常重要作用。为了研究大长径比机载导弹弹射分离过程中与载机之间的相互干扰以及导弹在分离过程中相对于载机的运动轨迹,该文分别使用刚体六自由度(6DOF)方法和计算流体力学/计算结构动力学(CFD/CSD)双向流固耦合方法对典型空空导弹发射分离过程进行了数值模拟,刚体6DOF方法基于对流体力学控制方程与外弹道6DOF运动方程的耦合求解,而CFD/CSD双向流固耦合方法基于对流体力学控制方程与结构运动方程的耦合求解。两种方法得到了导弹分离时的整个气动流场及其变化特性,揭示了不同时刻导弹气动系数随时间的变化曲线和导弹弹道参数,比较与分析了两种计算结果的异同,并对导弹结构弹性变形对其分离运动的影响进行了讨论。

Safe and stable separation process of a missile from an aircraft is very important for both the flight stability of the missile and the safety of the aircraft. To study the aerodynamic interference between the missile and aircraft, and the flight trajectory of the missile during the ejecting process, numerical simulation of the separating process of a typical air-to-air missile with high length-to-diameter ratio is carried out with two types of numerical methods, that is, the rigid body six degree of freedom（6 DOF） method and the computational fluid dynamics/computational structure dynamics（CFD/CSD） two-way coupling method. The rigid body 6 DOF method is based on the coupling of the governing equations of fluid dynamics and the 6 DOF exterior ballistic code, and the CFD/CSD two-way coupling method includes the coupling of the governing equations of fluid dynamics and the structural dynamics equations. The aerodynamic characteristics and variations of the flow fields are obtained by these two different methods. The time histories of aerodynamic coefficients and the trajectory parameters are displayed. Their similarities and differences are compared and analyzed. Furthermore, the influence of the elastic deformation of the missile structure on the separating movement is discussed.