不同雷诺数下展向凹槽对高负荷扩压叶栅损失特性影响的数值研究

Numerical Study on Influence of Spanwise Grooves on Loss Characteristics of Highly Loaded Compressor Cascades under Different Reynolds Numbers

关键词:  展向凹槽  扩压叶栅  损失特性  数值研究  轴流式压气机

Key words:  Spanwise groove  Compressor cascades  Loss characteristics  Numerical study  Axial compressor

摘要:

为研究吸力面展向凹槽在不同雷诺数下对叶栅损失特性的影响，以高负荷扩压叶栅为研究对象，基于数值模拟方法深入分析了不同凹槽方案对叶栅损失的控制效果。研究结果表明：在雷诺数为5.5×10⁵条件下，展向凹槽使吸力面湍动能增加，转捩提前，同时凹槽的扰动会造成较大的湍流边界层损失，使得总体损失增大，但合理的凹槽设计仍可有效改善-9°冲角条件下的流动损失；在雷诺数为1.35×10⁵和4×10⁴条件下，展向凹槽改善了叶型前缘载荷分布，抑制了层流分离泡的发展，在设计冲角条件可使总压损失最大减小8.45%。随着雷诺数降低，展向凹槽组位置越靠近叶型前缘，在-9°~+6°冲角内，其减损效果越好。但在设计冲角条件下，3-4-5-6凹槽组的作用效果在3种雷诺数下均是最优的。

Abstract:

In order to study the influence of spanwise grooves on the suction surface under different Reynolds numbers （Re） on the loss characteristics of highly loaded compressor cascades， the control effects of various design schemes on cascade loss were deeply analyzed by numerical simulation. The results show that at Re=5.5×10⁵， the arrangement of the grooves increases the turbulent kinetic energy of the suction surface and advances the transition. At the same time， the disturbance of the grooves can cause a large turbulent boundary layer loss， which increases the overall loss. But reasonable design of spanwise grooves can effectively improve the flow loss under the attack angle of -9°. At Re=1.35×10⁵ and 4×10⁴， the groove increases the loading distribution on the leading edge of the blade， the laminar separation bubble is suppressed， the total pressure loss can be reduced by 8.45% at the design angle of attack. With the decrease of Re， spanwise groove group are arranged closer to the leading edge of the blade， it can effectively reduce the loss under a wide range of attack angles of -9°~+6°. But under the condition of the design angle of attack， the effect of the 3-4-5-6 groove group is the best under the three above Re.