复合弯掠优化对跨声速压气机性能影响的研究

Effectiveness of Composite Optimization of Lean and Sweep on Transonic Compressor Performance

关键词:  跨声速级  优化  参数化  二次泄漏  激波结构

Key words:  Transonic stage  Optimization  Parameterization  Double-leakage  Shock wave structure

摘要:

为了研究复合弯掠优化对跨声速压气机性能的影响，以一跨声速级为对象，基于数值方法对优化前后的压气机整体性能和近设计点工况下转子内的流场进行了对比分析。结果表明:复合弯掠可以有效改善转子内部的流动和提高压气机的性能，其中近设计点的效率提升了约0.9%，近失速点效率提升约0.2%。复合弯掠可以使得负荷沿展向和弦向重新分配，改善了尖部和根部附近的流动；激波的空间结构发生了改变，全叶展上的激波均整体后移且尖部附近激波形态由一道前缘强斜激波转变为一道前缘弱斜激波和一道通道激波组成的激波系。复合弯掠也降低了叶尖“二次泄漏”的影响范围，使主流与泄漏流交界面的位置向下游移动，减小了叶尖附近通道内的堵塞和熵增区域。

Abstract:

In order to study the effects of the composite optimization of lean and sweep on the performance of transonic compressor，a transonic stage was conducted with numerical simulation. Comparison and analysis of compressor overall performance and the flow field near the design point in the rotor were performed before and after optimization. The results show that the composition of lean and sweep could improve the flow in the rotor and the compressor performance effectively. It is found that the efficiency was improved over the whole working condition by about 0.9% near the design point and about 0.2% near the stall point. The composition of lean and sweep could redistribute the loads along the blade span and chord，and the flow was improved near the blade tip and hub. The 3D structure of shock wave was changed by making it move backward over the whole blade span，and the form of shock wave near the tip was changed from a strong oblique shock wave at the leading edge to a shock wave system，which consists of a weak oblique shock at the leading edge and a passage shock wave. The composition of lean and sweep also reduced the influence range of double-leakage phenomenon at the blade tip，and it made the interface location of main flow and tip leakage flow move more backward，which reduced the passage blockage near the blade tip and the range of entropy production.