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.