本文利用表面热膜对某高负荷压气机叶片吸力面附面层的分离过程进行了实验研究,捕捉到了边界层分离点的位置及其随攻角的变化情况,给出了利用表面热膜测量的准壁面剪切应力来预判分离先兆和分离点位置的判据。同时,分析了Re数对附面层分离特性的影响。结果表明:准壁面剪切应力及其均方根极小值对应的位置点是进入分离泡内的第一个测量点;在所有测量的工况条件下,表面热膜都捕捉到了吸力面附面层的长分离泡,并能准确捕捉到攻角所引起的分离点位置变化;低Re数下,Re数对附面层分离影响较小。
The boundary layer separations on the suction surface of a highly-loaded compressor blade were performed in a low-speed linear cascade wind tunnel with steady inflow condition. Detailed flow field measurements were made using hot-film measurements over the suction surface of the airfoil to examine the development of the separation process of the suction surface boundary layer under various levels of different Reynolds number and inlet flow angle. The location where the quasi-wall-shear stress and its RMS get to their local minimum is the first measure point dipped by separation bubble. Long separation bubbles on suction surface were present for all flow conditions examined, and the variations of separation locus caused by inflow angle were captured by hot-film accurately. The Reynolds number hardly affects separation process under low Reynolds number conditions.