并行环境下外挂物动态分离过程的数值模拟  

Numerical Simulation of Dynamic Process of Store Separation in Parallel Environment

作　　者：肖中云[1] 江雄[1] 牟斌[1] 刘刚[1] 

机构地区：[1]中国空气动力研究与发展中心,四川绵阳621000

出　　处：《航空学报》2010年第8期1509-1516,共8页Acta Aeronautica et Astronautica Sinica

基　　金：国家"973"计划(61351-03-03)

摘　　要：并行工程的发展提出了计算流体力学的发展新概念,在此基础上研究开发了一个以非定常流计算为核心的多体分离数值仿真集成系统。该系统采用运动嵌套网格方法,能够处理飞行器在空间中的大尺度运动,结合六自由度运动学方程,具有实时仿真运动部件在气动力、弹射力和重力等耦合作用下运动的能力。基于外挂物投放数值模拟具有网格运动、非定常的特点,从网格重建、多重网格方法等方面探索了提高计算效率的途径和实现方法,结合并行化计算使分析周期大大缩短。以20个中央处理器(CPU)为例,并行计算和3层多重网格使计算速度提高约40倍,同时分布式存储、并发计算的特点缓解了对单节点的内存需求,解决了工程应用中受计算周期、网格规模等限制的难题。为了验证本文方法的正确性,对外挂物投放标模实验进行了数值仿真,计算得到的外挂物运动轨迹在0.5 s时间范围内与实验值基本吻合;对分离过程后半段出现的偏差,从气动力变化的时间历程上进行了说明,提出偏航力矩的误差和累积效应导致了预测出现偏离,对关键的分离初始阶段,该方法可以取得令人满意的效率和精度。The development of concurrent engineering has generated a new concept of computational fluid dynamics,and based on this a new integrated system of numerical simulation is developed which takes unsteady flow computation as its core.Using moving overlap grids,the system can compute the flow field of objects undergoing large overall motions,and can simulate motion under the effect of aerodynamic loads,gravitation and launch force based upon the 6-degree-of-freedom motion equations.As the simulation of store separation is characterized by moving grids and time accuracy,this research studies grid rebuilding and multigrid methods to improve the computation effectiveness,and achieves high efficiency under parallel environment.In the case of 20 central processing units（CPU）,the parallel computation and 3-level multigrids shorten the running time by 40 times.The newly developed code is validated by the simulation of calibration test of store separation from wing.The computational results are basically consistent with the testing data in the first half second.As for the deviation that appears in the latter stage of separation,the time history of the aerodynamic loads is discussed in detail,and the yawing moment error and the accumulation effect are considered to be the main cause.Fortunately,for the key first half second in the separation process,the simulation system achieves comparatively high efficiency and accuracy.

关 键 词：外挂物分离 并行计算 非定常 动态重叠网格 多重网格 

分 类 号：V211.3[航空宇航科学与技术—航空宇航推进理论与工程]