Effect of a bionic trailing edge on the propulsion performance of the ducted propeller

Abstract

Based on bionic mechanisms, this paper proposes a method to improve the propulsion performance of a ducted propeller by adding serrated protrusions onto the latter part of the JD75 duct, thus optimizing the internal flow field of the duct and recovering the energy of its wake. Combining the SST k-ω model and the moving reference frame method, the hydrodynamic coefficients of the Ka4-5508 propeller with JD75 duct propeller are calculated using computational fluid dynamics software. The reliability of the hybrid mesh generation method is verified by contrasting the coefficients with experimental results. Then, by adopting the control variable method, the effects of quantity, length, and inclination angle of serrated protrusions on the propulsion performance of the ducted propeller are studied. The results show that, compared with the traditional ducted propeller, the thrust and torque coefficients of the bionic trailing edge ducted propeller can be increased by, respectively, 32.4% and 24% at most. Correspondingly, its propulsive efficiency can be increased by up to 6.7% when the advance coefficient is 0.7. Lastly, according to the results, the proposed bionic trailing edge ducted propeller is more suitable for situations with a high advance coefficient, which can lead to higher efficiency and produce lower operating noise.