Experimental evaluation of steady-state effect of inlet radial total pressure distortion under multistage environment

In order to evaluate quantificationally the steady-state effect of inlet radial total pressure distortion on a highly loaded multistage axial compressor,the experimental investigation of two types of radial total pressure distortions including hub distortion and shroud distortion effects on the overall and stage performances of the compressor was performed using the pressure distortion mesh and the airfoil-probe technique.The experimental results indicate that both the radial total pressure distortions deteriorate slightly the overall performance and the stability margin of the compressor.The effect of shroud distortion on the overall performance parameters agrees well with hub distortion,while the stability margin loss caused by shroud distortion is larger than that caused by hub distortion(the maximum deviation is equal to 2%).The inlet radial non-uniform airflow mixes quickly in the flowpath of the compressor and produce the corresponding total pressure loss in the mixing process.In addition,both the inlet radial total pressure distortions affect the distribution of stage loading,which results in the improvement of one stage characteristic in comparison to that in the inlet uniform condition.The above physical phenomenon is relevant to the variation range of the attack angles of the rotor blade rows.