Numerical analysis on propulsive efficiency and pre-deformated optimization of a composite marine propeller

The objectives of this paper are to numerically investigate the performance of a composite propeller through bidirectional FSI algorithm combining CFD and FEM, and to improve its propulsive efficiency by a pre-deformated method. Numerical results are presented for the composite propeller which has been modeled by unidirectionally stacking with glass-fiber reinforced composites. The propulsive efficiency of the composite and rigid propellers with different advance coefficients J has been compared. The results show that the efficiency of the composite propeller is obviously higher than that of the rigid propeller when J≤0.8, which is attributed to the decrease of pitch angle caused by the bend-twist coupling effects. But for the design condition J=0.851 and the cases with J 0.851, the efficiency of the composite propeller is significantly lower than that of the rigid propeller, which is because the angle of attack α_composite is deviated from the optimal angle of attack α_design more than that for the rigid case α_rigid. Based on the optimization by the proposed pre-deformated method, the efficiency improvement of the composite propeller at the conditions with J≥0.851 could be obtained, and the composite material used in this work can meet the strength requirement of the designed propellers.