Research On Supersonic/Transonic Turbine’s Shock Phenomenon And Its Regulations

Traditional methods of turbine design have been widely applied and they are based on such an important assumption that stators and rotors operate in relative steady flow conditions.Deviation from real case is thus raised by these design methods particularly in the case of supersonic/transonic design condition.Shock and the phenomena it caused have big adverse effect on the flow in supersonic/transonic turbine that has become a key factor to improve the performance of turbine constraints.Reseach on the unsteady flow features and shock in turbine is the focus of turbine designers around world.To research the issue, several parts of work have been done by the means of theory analys and numerical simulation.TTM,the supersonic/transonic turbine designed by University of Graz is researched by using Numeca.Its shock structure and loss mechanism is revealed,and the interaction between shock and wave is analyzed.TTM is optimized with the adjoint method under five conditions.The changes of blade,performance and the flow features are analyzed.It is found that the ajoint method can weaken shock and improve the performance of supersonic/transonic turbine.The research shows that supersonic/transonic turbine optimized under near design condition can get a better result.Three kinds of axial spacing of supersonic/transonic turbine cascadeis designed for research by using Fluent under unsteady CFD model.The difference between steady and unsteady results are compared in different axial spacing.The detailed changes of pressure distribution, shock structure, flow features and over performance in different axial spacing are researched.The research shows that interaction of shock and wave can be adjusted by changing axial spacing,which also can regulate the load of understeam rotor blade.BitMesh is developed to rapidly generate mesh of axial turbomachinery blade and improved to add functions such as generating multi-stage mesh,felliting at hub and casing, generating single-row and multi-blade mesh.The mesh generated by BitMesh has a higher quality and shorter time,which is the basis for further research on turbomahchinery.