旋转状态下气膜偏转特性的实验

基于一个平板叶片模型对旋转状态下气膜冷却轨迹的偏转规律进行了研究,提出采用一个主流径向压力梯度与冷气所受惯性力之比的无量纲数Φ来评价气膜的偏转规律,并通过实验手段验证了这一理论,得出了此无量纲数与气膜偏转角度的关系.实验利用热色液晶测温技术对叶片表面的二维温度场进行测量,并采用无线旋转拍照系统对旋转坐标系中的图像信号加以采集.实验结果表明气膜沿径向偏转角度随Φ增大而减小.

Film deflection measurements of a rotating film cooling model

An experimental study was performed to investigate the deflection of film trajectory on a flat blade model under the rotating operating conditions. The moving trajecto-ry of film was mainly governed by the inertial force and radial pressure gradient in the blade passage. A new dimensionless parameter Φ, which is related to the ratio of the above two forces to determine the radial deflective angle of the film trajectory, was demonstrated in the present study. The steady-state thermochromic liquid crystal (TLC) technique was employed for flow visualization, and all the signals from the rotating reference frame were collected and transmitted to the stationary receiver via a wireless launcher, which was fixed in the rotation laboratory bench. The experimental results demonstrate that the spanwise deflection of film trajectory decrease with the increase of Φ values.