吸力面上气膜冷却对涡轮叶栅流场影响的实验研究

利用气动探针测量和墨迹显示方法，对不同实验方案下，带吸力面气膜冷却的某型涡轮导向器叶栅流场结构进行了实验研究。结果表明，冷气射流与燃气主流的掺混以及卵型涡的形成，使得吸力面根部出现了与通道涡旋向相反的涡系；卵型涡始终以一定形式存在于叶片表面，直到叶栅出口与尾迹相互作用后才达到均匀状态；冷气射流很难进入到通道涡分离线与端壁所形成的三角形区域中，通道涡分离线明显向端壁方向下移。

EXPERIMENTAL STUDY ON FILM COOLING ON A SUCTION SURFACE OF A PLANE TURBINE CASCADE

The flow field structure of a film cooled turbine for a typical design with four rows of cooling holes on the suction surface has been investigated in a plane cascade rig by the aid of flow visualization techniques and pneumatic probe measurement.The experimental results showed that a little vortex in opposite direction of rotation emerged as the passage vortex existed at the root of suction surface.The vortex was induced mainly by mixing between mainstream and injecting air,and resulted from formation of kidney-shaped vortex.The injected air was essentially absent in a triangular region extending from near the region of peak curvature on the blade to its trailing edge,and the separation line of the passage vortex was skewed toward the end wall.A very complex three-dimensional flow occurred in the downstream of the jet exit,and remained near the blade surface at the exit of the cascade.The kidney-shaped vortex was kept near the blade surface,and mixed with the wake at the exit of the cascade.