非定常机匣处理扩稳实验研究

AN EXPERIMENTAL INVESTIGATION OF STALL MARGIN IMPROVEMENT WITH UNSTEADY CASING TREATMENT

针对一种非定常处理机匣,在轴流风扇实验台上开展偏流吹气扩稳实验研究。主要包括:改善风扇稳定裕度的稳态特性;影响失速先兆波产生及发展的动态分析。结果表明:非定常机匣处理能够在不同工作转速下对风扇稳定裕度有显著效果,效率没有明显改变。偏流吹气可以进一步改善风扇稳定裕度,但同时也会带来一定的效率损失。动态分析证实处理机匣没有阻止失速先兆波的出现,而是有效地抑制了其非线性发展。

Casing treatments are widely used to enhance the stall margin of fan or compressor of aircraft engine. Based on the knowledge of the unsteady characteristics caused by casing treatment, it is verified that recessed casing treatment can be modeled as a wall boundary condition, which can be calculated by means of vortex sound theory. In the present work, experimental investigation is conducted with emphasis on the effect of unsteady casing treatments with injection on the stall margin and efficiency of a low speed fan/compressor. The results show that the unsteady casing treatments can improve the stall margin without incurring recognizable efficiency loss; the unsteady easing treatment will delay the non-liner development of stall process due to suppressing the propagation of inception wave compared with the evolution of the inception wave without casing treatments.