Experimental investigation on the flow instability mechanism for a counter-rotating axial compressor

The quest for enhancing thrust-to-weight ratios in aero-engines continues to promote, yet the potential for conventional compressors to further augment thrust by increasing stage load is constrained by material limitations. The counter-rotating axial compressor (CRAC) represents an innovative technology poised to markedly enhance the thrust-to-weight ratio of aero-engines by substantially reducing compressors’ weight through the elimination of stator blades. Nonetheless, the counter-rotational effect exacerbates internal aerodynamic challenges within CRACs, narrowing the stable operational range and limiting its engineering applications. To facilitate the engineering deployment of CRACs, it is imperative to develop flow control strategies on the basis of a comprehensive understanding of the instability mechanisms in CRACs. At present, the flow instability mechanism of CRACs remains unclear, the experimental studies on instability of the CRAC are mainly performance experiments, the investigation on instability and recovery process of the CRAC is mainly based on numerical simulations, and experimental investigations are notably lacking. Therefore, a two-stage CRAC model is chosen as the investigated object, and a dynamic measurement system suitable for the dual-rotor refinement flow field measurement of CRACs is established, and the dynamic experimental measurement is performed. The flow instability mechanism of the CRAC is revealed through the spatio-temporal decoupling of the dynamic pressure data and the reconstruction of the tip flow field during the compressor's flow instability and stall recovery.