主流物性参数对燃气涡轮冷却叶片气热耦合性能评估影响

As an attempt to clarify the effect of thermophysical property settings of the mainstream working fluid on the turbine vane cooling effectiveness assessment and their definition principles in the conjugate heat transfer numerical simulation， three dimensional conjugate heat transfer analysis of the preliminary cooling design of a gas turbine vane was conducted in this study，where both the vane surface temperature distribution and the average cooling effectiveness discrepancies with distinct defining methods of the mainstream specific heat capacity， dynamic viscosity and thermal conductivity were carefully examined. Moreover，the influencing mechanism and selection principle of the mainstream thermophysical properties were also analyzed and proposed. Results show that the mainstream flow and heat transfer characteristics around the vane are dissimilar，resulting from the unequal turbine inlet Reynolds number，passage Mach number and Peclet number of different thermophysical properties，among which the Peclet number is found to play a key role in deriving more accurate temperature profile for the turbine vane. Meanwhile， compared with the specific heat capacity and dynamic viscosity， keeping the thermal conductivity of mainstream consistent with the hot gas would guarantee a more reliable evaluation of the cooling performance for turbine vane.