关键词: 半开式离心压气机, 抽吸孔数目, 孔式机匣处理, 数值计算

Abstract: The holed casing treatment is demonstrated, by experiments and numerical computations, to be effective in expanding the stable working range of the centrifugal compressor with unshrouded impellers with no significant efficiency penalty. It is also indicated that the hole number has little influence on the effect of holed casing treatment. The parameter that is influenced most obviously is the choked margin. Three situations of 48 holes, 64 holes and 80 holes are computed and analyzed. It is found that the stall margin and the highest efficiency of the compressor decreases a little with the increasing of the hole number. This is because that the flows coming from adjacent holes suppress each other when the hole number increases. On the contrary, the choked margin and the efficiencies at large flowrate conditions of the compressor increases a little with the increasing of the hole number. This is because that the effect of holed casing treatment at large flowrate conditions is related with the bypass flow amount in the holes.

Key words: Hole number, Numerical computation, Centrifugal compressor with unshrouded impellers, Holed casing treatment