旋转状态边界层速度场及温度场特性实验

针对涡轮转子叶片内冷技术,使用TR-PIV(time resolved particle image velocimetry)技术与热线技术同步原位测量了壁面加热条件下旋转通道内边界层速度场和温度场特性。结果显示:旋转数大于0.48时前缘面附近出现了回流现象,并从受力分析的角度给出了解释;回流区一般出现于流场下游、较大密度比、较高旋转数下,可以利用回流区的影响达到增强前缘面换热的目的;得到了旋转条件下无量纲温度型、温度脉动量和努塞尔数的变化规律,可以看出湍流边界层内部的温度场分布在旋转效应的影响下产生了强烈的不对称性,与静止条件下的标准规律相比会产生一定的偏差。

Experiment on characteristics of velocity and temperature fields of rotating boundary layer

For the turbine rotor blade internal cooling technology, TR-PIV (time resolved particle image velocimetry) and hot wire technology were used to measure the velocity and temperature field of the boundary layer in the rotating channel under wall heating conditions. The results showed that when the rotation number was greater than 0.48, backflow occurred near the leading side, and an explanation was given from the force analysis. The backflow zone generally appeared downstream the flow field at a higher density ratio and a higher rotation number. The backflow effects can be used to achieve the purpose of enhancing the heat transfer of the leading side. The change laws of the dimensionless temperature profiles, temperature fluctuation and Nusselt number under different rotation conditions were obtained. The temperature field distribution inside the turbulent boundary layer produced a strong asymmetry under the rotation effect, generating a certain deviation compared with the standard law under static conditions.