Stall inception prediction of axial compressors with radial inlet distortions

A stall inception prediction model considering radial inlet distortions is established in this paper in order to quickly and accurately predict the stall limit of a compressor at radially distorted inlet flow conditions. Furthermore, the quantitative effect of the radial inlet distortion on compressor stability is investigated on a low-speed single-stage axial-flow compressor which is named TA36 and located in Beijing University of Aeronautics and Astronautics. Two kinds of distortion intensities are achieved by two radial inlet distortion generators in experiments. By utilizing the developed stability model, the predicted stall limits of TA36 at clean, 10% and 20% radially distorted inlet flow conditions all agree well with the experimental data only with relative errors of −0.74%, 1.28%, and 0.53% respectively. These relative errors less than 1.50% validate the ability of the developed stability model to predict the stall onset of a compressor with clean inlet or radial inlet distortions. Moreover, the predicted results confirm that radial inlet distortions deteriorate the compressor stability, and the adverse effect becomes more severe with the increase of distortion intensity, which can also be concluded from the experimental data. After comparing the load distribution on the rotor blade at the three inlet conditions, the increase of the maximum load at the tip region at distorted inlet conditions is considered to be a critical factor contributing to the negative effect of radial inlet distortions on compressor stability.