Aerodynamic performance of coaxial counter-rotating propeller for air cushion ground effect wing vehicles

Abstract In the early stages of the design of an air cushion ground effect wing vehicle prototype, it is crucial to determine its power source. Compared with a single propeller, a coaxial counter-rotating propeller not only makes the torque uniform but also more efficient. Based on the STAR- CCM+ platform and slip grid model, the thrust and total thrust of the front/rear propellers under the conditions of the same rotational speed of coaxial counter-rotating propellers, different distances between propellers, and the same distances between propellers but different rotational speeds are simulated, respectively. The results show that the error between the simulated and experimental results of the aerodynamic characteristics of the single propeller in the model is within 7.4%, which proves the feasibility and applicability of the validated model. At the same rotational speed, the effect of distance on the total thrust is not significant, but the larger the distance, the smaller the interaction between the front and rear propellers and the more stable the output. At the same distance, the thrust increases with the increase of rotational speed. The optimum distance between the coaxial counter-rotating propellers of this air cushion ground effect wing vehicle was finally determined to be 0.35D and the optimum rotational speed was 4,800 rpm.