Technical Study On Diffusion And Cooling Of Supersonic And High Temperature Flow

In terms of diffuser and cooling system on supersonic and high temperature flow,the thesis does elementary studies.In aspect of diffuser,based on the two-dimensional axisymmetric and three-dimensional N-S equation,the thesis compares the flow field structure and the diffusion performance between the straight diffuser and the diffuser with second throat.Combined with the formation of the shock train,the structure of the shock train and the shock-boundary layer interference,the thesis explores a variety of diffusion efficiency of the diffuser and its influencing factors.Through the numerical simulation,deepen the understanding of the shock-boundary layer interference in the supersonic turbulent,enhance the awareness of the structure and performance of the diffuser,and my study provides some valuable research results for the engineering application of the diffuser:The main performance index of the diffuser is the back pressure resistance ability and the total pressure recovery coefficient,the overall performance of the diffuser with second throat is superior to the straight diffuser.Such as the length to diameter ratio and the expansion angle of the contraction will all have an effect on the performance of the diffuser.These factors should be considered in the diffuser design.There is no difference on the back pressure resistance ability and pressure recovery coefficient of the diffuser between the three-dimensional rectangular structure and the two-dimensional axisymmetric structure.Add diaphragm to the diffuser will influence the diffusion properties of the diffuser.Add clapboard can reduce the length of the shock train,so as to decrease the size of the diffuser structure.In aspect of cooling devices,the thesis designs a pipe and a plate exchanger cooling devices.Calculating the pressure drop and the cooling effect by engineering estimate and the numerical simulation,the thesis has played a certain reference function on the engineering application of the cooling device.