旋转状态下姿态控制发动机喷流流场的数值模拟

为了对姿态控制发动机在旋转状态时的喷流流场进行数值模拟，并避开复杂的滑移网格技术，将惯性坐标系下的控制方程和数值计算边界条件用弹体旋转坐标系来表达，选用雷诺平均的旋转坐标系下的Navier-Stokes方程，算例计算结果与采用滑移网格技术得到的流场结构相比更接近实测且计算容易收敛，表明这种方法正确且简单可行。数值计算结果表明：在弹体直径以及喷口大小及入口条件一定的前提下，由于旋转引起的喷流流动的非对称性将直接影响到姿态喷流控制力的大小和方向，进而影响到姿态控制发动机的工作效率；随着旋转角速率的增大，推力矢量明显变化，控制推力偏转，使有效揎制推力减小，从而影响远程火箭弹的稳定性和姿态控制精度，并在一定程度上增加了燃气消耗量。

The Jet Flow Field Simulations of a Rotating Attitude Control Motor

In order to simulate the jet flow field of attitude control motor in the case of rotating, and avoid using the complex sliding mesh technique, the governing equations and the numerical boundary conditions were given in the rotating frame of reference instead of the inertial fixed coordinates. The Renault averaged Navier-Stokes equation was employed combined with some knowledge of mechanics, and then a simple simulation example was given, which flow-field structure is converged easier and more similar to the practical measurement compared to that obtained with the sliding mesh technique. It can be shown that this method is feasible. Simulation results indicate that, on the condition that the figure parameter, structure parameter and gas parameter are changeless, the rocket rotation can affect the attitude control force vector and the work efficiency of attitude control motor, thereby affecting the flyight stabilization and attitude control precision of long-distance rocket. The level of rocket rotation affect mainly depends on the angle velocity of rotation.