Calculation Method Study Of Large Air Mixing With Gas In Turbine S₂ Stream Surface

The fully –matured quasi-3D aerodynamic design embodied values again when the turbine hierarchical aerodynamic designwas put forward. S2 stream surface calculating program is a core part of it, become one of important factors for improving the efficiency of the design work. High temperature gas turbines have a mass of cool air, which dramaticallyaffect the cascade aerodynamic performance, most studies show that the film cooling is the most significant effect. Cool air would obviously reduce the program computational accuracy, so continuing to improve the S2 stream surface program to satisfy new design requirement is necessary.The author represented the development and history of the turbine blade cooling design technologies and aerodynamic design system, and then made the detailed presentation to turbine internal flow loss mechanism, representative loss model and correlational studies of mixing loss. At last the author put forward three improvement suggestions: reasonable distribution of air quality source, control the air jet angle and consider the influence of the air for mainstr eam gas thermal properties.Finally, the author combined the mixing layer assumption, representative mixing loss model and S2 stream surface characteristic, built a lending kinetic energy loss calculation methods which apply to S2 stream surface, and meanwhile added BTИ’s mixing loss calculation method gotten by large experiments to S2 stream surface program. By comparing the results of S2 and CFX for two large cool air turbines, the primary loss model of S2 program has poor universality, and although these improvements can increase flow and power that S2 program estimate, and a degree of improving theseparameters prediction accuracy, but can’t obviously affect the distribution of parameters along the blade height.