A high frequency dynamic pressure sensor array arranged at the tip of the frontand rear rotors is utilized to capture the stall initial disturbance characteristics of a low-speed axial contra-rotating compressor with different speed configurationsand distortion conditions. The results obtained by analyzing the pressure waves collected at stall conditions show that the stall type at the design speed is rotating stall when the inlet flow is uniform, and the stall propagation direction is consistent with the rotation direction of the rear rotor. The maturely developed stall is fixed at a circumferential positionand does not rotate circumferentially when the speed ratio is 1.40. With further increase of speed difference in the frontand rear rotors, the type of stall disturbance changes again to rotating stall at the speed ratio of 1.52, and the stall disturbance propagates in the same direction as the front rotor rotation due to the reduced suction effect of the rear rotor on the front rotor wake. The stall disturbance characteristics at different speed ratios are all consistent with a uniform inlet when the compressor incoming flow is changed to be circumferential inlet distortion. However, the distortion will cause different amplitude fluctuations in the pre-stall pressure sequence at different circumferential positions. The Empirical Mode Decomposition-Local Mean Decomposition (EMD-LMD) method is employed to capture the small pre-stall perturbations that gradually accumulate energy over time.

With the enhancement of the coupling depth between the distributed propulsion system and the aircraft in terms of structure and aerodynamics, the blade source term model that balances calculation accuracy and efficiency plays an increasingly important role in the analysis and optimization of the internal and external flow coupling of the distributed layout. This paper systematically reviews the basic logic, implementation path and application results of the existing blade source term models for compressors, fans, propellers, etc., and provides support for the selection of blade source term models in the process of internal and external flow coupling analysis of distributed propulsion systems. Firstly, the applications and development of the descriptive and iterative body force methods based on the actuator disk model are reviewed and summarized. The Hough-Ordway model and its improvement ideas are discussed. The potential flow-viscous flow coupling and the iterative calculation strategy based on Blade Element Momentum Theory (BEMT) coupling are analyzed. Secondly, the applications and development of the analysis mode and the extraction mode body force model based on the Marble body force model are sorted out. The Gong model, the Hall model, and the improved Gong-Thollet model and Hall-Thollet model based on the analysis mode are discussed. Subsequently, the body force models of Turbine Engine Analysis Compressor Code (TEACC), Kiwada and Chima, which directly extract the blade source terms from the flow field data by using the streamline curvature method and the Reynolds-Averaged Navier-Stokes (RANS) equation calculation results, are discussed. Finally, the collected blade source term models are compared and analyzed, and specific suggestions for the applications of blade source term models in numerical analysis of rotating turbomachinery are given, which provides a reference for the integrated analysis of internal and external flow for balancing calculation accuracy and efficiency.