固体火箭发动机内流场分区耦合数值计算

NUMERICAL ANALYSIS OF COUPLED CHAMBER-NOZZLE FLOWS IN SOLID ROCKET MOTOR

采用分区耦合方法计算固体火箭轴对称燃烧室与喷管流场。对于低速的燃烧室流场，选用不可压流的Ｎ－Ｓ方程描述并用ＳＩＭＰＬＥＣ方法数值求解；对于高Ｒｅ数的喷管流场，则采用Ｅｕ－ｌｅｒ方程描述并用ＳＣＭ方法求解。计算时用燃烧室出流为喷管流场提供入口参数，同时用喷管流场压强分布反馈影响燃烧室流动状况。对耦合边界条件处理方法进行了探讨。对典型的侧壁加质燃烧室与喷管流场进行了计算，计算结果揭示了单独喷管流场计算难以反映的喷管收敛段近壁区的低速区域，与已有的燃烧室流场实验结果一致并反映了燃烧室与喷管流场之间的联系，较好地模拟了流动中的物理现象。

A zonal coupling technique is applied to an overall analysis of the entire axisymmetric two-dimensional chamber-nozzle flow field in a solid rocket motor.The incompressible Navier-Stokes equations are used to describe the chamber flow and solvedty SIMPLEC method.While the compressible Euler equations are appliced to the nozzle flow and solved by Split Coefficient Matrix (SCM) method.Coupling between the two different flow fields is reached gradually through boundary information exchange and iteration,in which the chamber flow provides all the necessary inlet boundary information such as total temperature,total pressure and flow angle for nozzle,and the nozzle flow provides back pressure for chamber outflow.The treatment of the coupling boundary conditions is discussed.A numerical example is considerd.It is shown that the computational results of coupled flow are more reasonable than those from separate simulation,especially in the low speed region near the inlet nozzle wall and in good agreement with available chamber axial velocity profiles.