Experimental investigation and detached-eddy simulation of compressor aerodynamic performance in inlet distortion

This paper presents an investigation into the interaction between a low-speed compressor and a circumferential inlet distortion, through high-resolution measurements and full annulus Detached-Eddy simulation. Experimental results show the compressor behaviors with inlet distortion, and three novel distortion coefficients are presented to build the relationship between the distortion features and the compressor characteristics. Through the unsteady simulation and casing pressure, the rotor stall process with inlet distortion is well captured. Differing from normal ‘spikes’ form, the stall process can be divided into three stages. First, the stall inceptions occur in those blade tips with high blade loads. They can circumferentially propagate several blade passages, but reduce and disappear quickly when they move to low-load blade zone. Then, some of the stall inceptions develop into unsteady stall cells, which can propagate to all the blade passages but may disappear after several cycles. Finally, one of the stall cells becomes stable and the rotor runs into a rotating stall. Comparing experimental and simulation data, Detached-Eddy simulation can provide more details of the stall process than the RANS method. But it is still not precise enough to predict the rotor stall point with inlet distortion.