来流湍流度对超高负荷低压涡轮附面层流动控制手段的影响

实验研究了表面粗糙度耦合上游尾迹的流动控制技术，分析了来流湍流度（FSTI）在流动控制过程中对叶片吸力面附面层分离、转捩特性的影响.实验发现:在速度峰值点至分离点之间布置粗糙高度与弦长之比为1.05×10-4的粗糙条带可以在来流湍流度为0.4%与2.2%的低雷诺数范围内降低叶型损失.在雷诺数为85000的状态下，FSTI影响了尾迹通过区、尾迹诱导转捩区及自然转捩区的附面层动量厚度，造成了叶型损失的差异，但FSTI对抑制区的影响较小. 

Effect of freestream turbulence intensity on boundary layer flow control strategy of ultra-high-lift low pressure turbine

The flow control strategy combined upstream wakes and surface roughness on boundary layer development were investigated experimentally, and the effect of freestream turbulence intensity(FSTI) on the separations and transitions characteristic of the boundary layer in the flow control process was also studied.Result shows that the roughness strip with the ratio of roughness height and chord of 1.05×10^-4 deposits between the velocity peak and separation onset can reduce the profile loss at freestream turbulence intensity of 0.4% and 2.2% in the low Reynolds number. At Reynolds number of 85000, the boundary layer momentum thickness in wakes passing region, wakes-induced transition region and natural transition region is affected by the FSTI, thus, resulting in a difference of the profile loss at the two operating conditions. However, there is no variation of the calmed region at different FSTI.