Effects of Inlet Distortion on the Stability of a Transonic Multi-Stage High-Pressure Compressor: A URANS-Validated Body Force Approach

This paper presents a modified Body Force model tailored to an industrial 4.5-stage high-pressure compressor, with the aim of improving the accuracy of performance and stability margin predictions for such configurations, and of investigating the effects of inlet distortion on operability and model robustness. Key modifications include calibrated aerodynamic coefficients, a physically motivated clipping of the loss-related force component to enhance boundary layer behavior, and the incorporation of secondary loss modeling terms. The model is validated against URANS simulations, showing a significant reduction in global performance prediction error and improved near-wall accuracy under clean inlet conditions. Under circumferential inlet distortion, the model accurately captures both global and local flow features, including distortion transport and azimuthal asymmetries. Further analysis reveals dissipation of total pressure deficits, generation of secondary losses, and temperature distortion driven by flow redistribution. At high distortion intensities, the model identifies near-stall instability and hub separation, suggesting that this behavior may contribute to stall onset in the investigated compressor.