Aerodynamic profile optimize for gas turbine exhaust diffuser strut based on NACA airfoil
                                                     DAI Bin, SUI Yongfeng, XIN Xiaopeng, LAN Jibin, CHU Peng
                       (Central Research Institute,Hangzhou Steam Turbine Power Group Co., Ltd., Hangzhou 310016, China)

Abstract: Aiming at the problem of gas turbine radial exhaust diffuser strut aerodynamic, the original aerodynamic profile of the strut was optimized with the NACA airfoil and two new aerodynamic profiles were designed. The steadystate and transient numerical simulation method were used to study the 10%, 50% and 90% radial height sections Mach number distribution of diffuser, total pressure loss coefficient of strut downstream, static pressure, static pressure recovery coefficient, the passage vortex, outlet static entropy of the exhaust diffuser and effect of turbine final stage wakes on exhaust diffuser static pressure recovery coefficient. Steadystate results indicate that the new struts delay the separation, strut downstream total pressure loss coefficient is reduced, and static pressure recovery coefficient of the exhaust is obviously improved. The transient results indicate that the final stage vane and rotor wakes have little effect on the static pressure recovery coefficient of the radial exhaust diffuser.

Key words: exhaust diffuser; strut; total pressure loss coefficient; static pressure recovery coefficient