以燃气轮机叶片为研究对象,设置主流风速为10 m/s,采用热膜风速仪作为测量工具,对气膜冷却叶片压力面和吸力面下游指定位置的二维速度进行了测量.结果表明:当射流比增大时,压力面和吸力面主射流掺混中心上移,在叶片型面曲率梯度较大处会出现回流现象,混合流体贴壁性变差.吸力面速度u梯度明显增加,吸力面流体贴壁性好于压力面.随着x/d的增加,压力面一侧速度u逐渐变得不规则,在叶片曲率较大处的近壁区出现了明显的二次流,吹风比对吸力面一侧速度v的影响比对压力面一侧的影响小.
Taking the gas turbine blade as an object of study,setting the mainstream velocity at 10 m/s,two-dimensional velocities in a specified position downstream of both the suction and pressure side of a film cooling blade were measured using hot-film anemometer.Results show that with the rise of injection ratio,the mixing center of mainstream and jet injection rise,the adherence of the mixing flow to the wall worsens,and entrainment flow occurs at the position where the blade surface has a large curvature gradient.The gradient of u velocity on suction side increases significantly,and the level of the flow adherence to the wall is better than the pressure side.With the rise of x/d,the velocity u on pressure side gradually gets irregular,and secondary flow occurs near the wall where the curvature is great.Influence of the blowing ratio on suction side velocity v is smaller than on the pressure side.