复杂进口边界对高压级压气机性能影响分析

Influence of Complex Inlet Boundary on High-Pressure Stage Compressor Performance

建立了带有级间管道的高压级压气机模型,对比分析了在均匀进气条件和非均匀进气条件下,下游高压级压气机的流场变化。结果表明:不论是均匀进口边界条件还是不均匀进口边界条件,高压级进口都出现了明显的周向畸变,压力呈现“外高内低”的分布形式,在弯管和直管的转换处,存在流动漩涡,说明高压级进口的周向畸变主要是由于高压级进口弯扭形状的管路引起的。此外,通过对高压级压气机叶间流场进行分析,发现50%槽道展向高度位置的流场明显受到蜗舌引起的周向不均匀压力场的作用,即蜗舌的左侧都存在明显的高熵区域,这可能是由于蜗舌处高静压的作用,导致蜗舌左侧气流流动受阻,从而诱发流动分离所致。在90%槽道展向高度位置,蜗舌的作用减弱,间隙泄漏流动引起的损失更加明显。

The model of high-pressure stage compressor with interstage pipeline was established and the flow field changes of downstream high-pressure stage compressor were compared and analyzed under uniform and non-uniform inlet conditions.The results show that the obvious circumferential distortion occurs at the inlet of high-pressure compressor and the pressure distributes in the form of high outside and low inside,no matter whichever the inlet boundary condition is.There were also some flow vortices at the transition between the bend and straight pipes,indicating that the circumferential distortion at the inlet of high-pressure compressor was mainly caused by its twisted-shape pipeline.Moreover,it was found that the flow field at 50% span was obviously affected by the uneven circumferential pressure field caused by the volute tongue through the analysis of flow field between the blades of compressor.The high entropy areas formed on the left side of volute tongue possibly because the blocked flow led by the high static pressure resulted in flow separation on the left side of the volute tongue.Besides,the effect of volute tongue weakened at 90% span and the loss caused by the tip leakage flow was more obvious.