高主流湍流度下密度比对涡轮导叶全气膜冷却特性的影响

In order to study the effects of the secondary flow density ratio on the full film cooling characteristics of turbine guide vane with high mainstream turbulence, the film cooling effectiveness and heat transfer coefficient of a three-dimensional turbine guide vane model were measured using transient liquid crystal technique. The mainstream turbulence is 15% and the secondary flow density ratios are 1.0 and 1.5. The secondary flow mass flow rate ratios are 7.0% and 12.5%. The results show that the high density ratio decreases the momentum of film jets: in low mass flow rate ratio condition, the coolant with lower momentum on the leading edge and the first half of pressure side is easier to dissipate, which decreases the film cooling effectiveness; in high mass flow rate ratio condition, the decrease of secondary flow momentum enhances the attachment of coolant in the downstream of film holes, which increases the film cooling effectiveness and film coverage. In low mass flow rate ratio condition, the effect of the high secondary flow density ratio on the heat transfer of vane is insignificant; in high mass flow rate ratio condition, the increase of secondary flow density ratio decreases the average heat transfer coefficient ratio in the middle chord region of suction side and the second half of pressure side by 15% and 25%, respectively.