Influence mechanism of advance ratio on the aerodynamic performance of a contra-rotating propfan

Contra-rotating propfan (CRP) emerged in the context of the oil crisis in the 1970s and 1980s. The understanding of the flow mechanism of CRP has been continuously deepened with the research on the three-dimensional (3D) flow and design parameters of CRP. This paper conducts a study on the advance ratio of a CRP and explores its 3D flow characteristics. The results show that increasing the advance ratio can weaken the blade-induced acceleration effect on the flow, the thrust coefficient decrease from 0.9 to 0.31. As the advance ratio increases, the axial induction coefficient decreases, and the acceleration effect and power decrease, the circumferential induction coefficient of the front blade decreases. The circumferential induction coefficient of the rear blade is affected by the incoming flow and fluctuates at different radial positions, affecting the rotational effect of the CRP. The combined effect of these leads to a decrease in the axial vorticity of the tip vortex and the trailing edge vortex.