Effect of bevel angle of three-layer parallel plate on hydrodynamic performances of otter-board

摘要

The effect of bevel angle of three-layer parallel plate of otter-board on hydrodynamic performances is investigated by model wind tunnel test. Four otter-board models are designed with four different bevel angles (8°, 10°, 12° and 14°), and tested under the wind speed 28 m/s in wind tunnel. Model experiment is conducted to obtain the drag coefficients C_x, the lift coefficient C_y, the pitch moment coefficient C_m, the center of pressure coefficient C_p and calculated the lift-drag ratio C_y/C_x. The result shows that the maximum lift coefficient and the maximum lift-drag ratio of the otter-board model with a bevel angle 12 degree is higher, there is 2.598(α=65°) and 2.607(α=37.5°), For comparison in stability of otter-board, the stability of the otter-board model with the bevel angle 8 degree is better by the comparative analysis of C_m and C_p, the absolute value of C_m is 0.174 and the minimum variation coefficient of C_p is 4.37%. The results can offer reference for the structural optimization design of trawl otter-board.