The Role of Tip Leakage Flow in Triggering Rotating Stall of a Low Speed Compressor under Inlet Distortion

The stall behavior in a single-stage low-speed axial compressor under rotating inlet distortion (RID) is investigated in the first half of this paper. The tests demonstrate that the tip leakage flow (TLF) plays an important role in triggering rotating stall. The tracking of the spike-like disturbances caused by the spillage of TLV indicates that most of such spike-like disturbances will be smeared by non-distorted sector and the growth of the spike-like disturbances actually relate closely to how and how often the path of the propagating disturbances come across the path of the rotating distorted sector. In the second half of this paper, micro air injections are applied to test the effect behavior of TLF on stall inception. Contrasts to without micro air injections, the spike-like disturbances are much fewer, so the possibilities that spike-like disturbances may trigger rotating stall are fewer too. As a result, the compressor gets a lower mass flow rate at stall for both co-rotating inlet distortion and counter-rotating inlet distortion.