压气机进口畸变流场的主动控制

一 引言 航空喷气发动机进口的气流畸变对压气机的性能和稳定性造成很大的影响,发动机的抗畸变能力已成为评价发动机性能的一个重要指标。目前发动机设计时往往留有高达20％的失速裕度,也与防止进气畸变使压气机进入不稳定工作有关。留用大量的失速裕度意味着压气机性能的浪费。如果能增强压气机的抗畸变能力,使之在进口气流品质较恶劣的情况下也能稳定工作而不进入旋转失速或喘振,则有可能将压气机的工作点移至压比与效率都更高的区域。由此得到的发动机性能提高是相当可观的。

ACTIVE CONTROL OF INLET DISTORTED FLOW FIELD IN COMPRESSOR INLET

The feasibility of alleviating the destabilizing effect of the inlet circumferential total pressure distortion on an axial compressor by active control of individually adjustable inlet guide vanes(LAIGV) has been qualitatively analyzed under the parallel compressor hypothesis. The result shows that when the distortion is quasi-steady it is possible to use the actively controlled LA1GV with a relatively simple proportional control scheme to adjust the flow angle, and thus to prevent the compressor entering the unstable state. For a typical blade setting the angular adjustment of LA1GV needed to cope with 10 % total pressure distortion is of only few degrees.