凹坑深度对高负荷扩压叶栅损失特性的影响

采用经实验校核的CFD方法研究吸力面不同深度的凹坑对高负荷扩压叶栅气动性能的影响。为研究不同凹坑方案对于叶栅损失特性的影响,深度为0.2、0.3、0.4、0.5、0.6mm,深宽比为0.25的5种凹坑分别被布置在42%~60%轴向弦长处。不同深度凹坑对于减小损失的效果不同。结果表明:深度为0.2mm的凹坑能够使得叶栅出口总压损失降低10.8%。三维球状凹坑通过提高边界层内的湍动能水平,促进边界层转捩,消除了层流分离泡,改善了矩形叶栅的气动性能。

Effects of dimples with different depths on loss performance of highly-loaded compressor cascade

The CFD investigation was verified by an experiment to study the aerodynamic performance of a highly-loaded compressor cascade with dimples of different depth. Five dimple configurations with diameters of 0.2,0.3,0.4,0.5,0.6mm and a depth-diameter ratio of 0.25, were arranged in 42%-60% axial chord lengths of suction side respectively, and studied to validate their effectiveness in reducing total pressure loss. The dimples with different depth exhibited different performance in loss reduction. Result showed that, a 10.8% loss reduction can be required under the influence of dimples whose depth was 0.2mm. Three-dimensional spherical dimples can promote the transition of the boundary layer by enhancing the turbulent kinetic energy level. Given the eradication of the laminar separation bubble on the suction side, an improved aerodynamic performance of linear cascade can be required.