变比热容对射流推力矢量喷管内流场影响的数值模拟

Numerical simulation on effects of variable specific heat capacity on internal flow field of jet vector nozzle

利用时间推进的有限体积法求解二维雷诺平均Navier-Stokes(N-S)方程,分别在变比热容和定比热容的情况下研究了射流推力矢量喷管的内流性能,并对两种情况下计算结果进行了比较.结果表明,与定比热容情况相比,工质为变比热容的燃气时,喷管内部由二次流产生的斜激波位置向喷管下游移动,回流区减小,喷管的推力矢量角和推力系数减小,温度越高,两种方法的计算结果相差越大.因此,在采用计算流体力学(computational fluidic dynamic,简称CFD)方法研究射流推力矢量喷管内流场性能时应该考虑变比热的影响.

Given certain variable specific heat capacity and constant specific heat capacity,two-dimensional Reynolds average Navier-Stokes equation was solved by using time marching method in finite volume,and the internal flow of jet vector nozzle was studied.The results gained from different cases were compared.The results show that：as compared with the specific heat capacity,when the shock wave generated by second injection moves toward downstream divergent section,the thrust vector angle and thrust coefficient decrease.With the increase of temperature,the gap between the results from two methods became wider.The influence of variable specific heat capacity must be take into consideration when studying the internal flow field of jet vector nozzle by the method of computational fluidic dynamic.