周向槽和阶梯槽在提高轴流压气机稳定工作裕度中的综合利用

Co-incorporation of circumferential grooves and stepped tip gap to improve the stable working range of axial compressors

在验证了计算模型的可靠性后,针对西北工业大学某轴流压气机转子的失速类型,进行了周向槽机匣、阶梯槽机匣,以及两者组合结构的扩稳效果的数值模拟。结果表明,周向槽结构在叶片通道前端可起到对叶顶泄漏涡的控制作用,而在叶片通道尾端效果不大。阶梯槽结构在叶片通道后端则能利用流向压差起到扩稳作用。采用叶片通道前部为周向槽,尾部为阶梯槽的组合机匣结构能在效率损失较小的情况下,对类似的压气机起到较理想的扩稳效果。

After the accountability of the computational model is verified, computational simulations of circumferential groove casing, stepped tip gap casing and the casing combined by the two configurations are performed on one axial-flow compressor of Northwest Polytechnic University. It shows that, when put at the forward part of the flow passage, the circumferential grooves can affect the location of Tip Leakage Vortex, while when pnt at the end of the passage, they nearly have no funetion to the flow field. The stepped tip gap, in contrast, can improve the stable working range of the compressor, when put at the end pavt of the passage by making use of the steamwise pressure gradient. A combined casing with the circumferential grooves at the forward part, and the stepped tip gap at the end part may achieve recognizable improvement on compressor stable working range, with relatively low loss.