Effects of Euler Angles of Vertical Cambered Otter Board on Hydrodynamics Based on Response Surface Methodology and Multi-Objective Genetic Algorithm

Abstract

Abstract In this present work, effects of three Euler angles (angle of attack (AOA), angle of trim (AOT), and angle of pitch (AOP)) of vertical cambered otter board on hydrodynamic characteristics (drag coefficient (Cd), lift coefficient (Cl), center-of-pressure coefficients (Cp)) were studied based on numerical simulation combined with Kriging response surface methodology (KRSM) and multi-objective genetic algorithm (MOGA). Wind tunnel experiments were carried out to validate the accuracy of the response surface based on numerical simulation. It was demonstrated that AOA had noticeable effects on Cd and Cl, while AOT and AOP had fewer effects. The working posture of the otter board was recommended to lean inward (0 deg–6 deg) and forward (−10 deg–0 deg) to improve the lift-drag ratio without sacrificing Cl. The influences of AOT and AOP on positions of center-of-pressure points were less significant than that of AOA and decreasing with the increase of AOA. Besides, the response surface of hydrodynamic coefficients around the critical AOA was a decent indicator of the occurrence of stall. Finally, three candidate cases were selected to satisfy the high working efficiency by MOGA, which was consistent with the above recommendations. This study provided a scientific reference of response surface experimental investigations methodology in the fishery engineering and the configuration of Euler angles of otter board.