The effect of the main-panel angle of a single-slotted cambered otter-board was investigated using engineering models in a wind tunnel.Three different angles(0,6,and 12)were evaluated at a wind speed of 28 m/s.Para...The effect of the main-panel angle of a single-slotted cambered otter-board was investigated using engineering models in a wind tunnel.Three different angles(0,6,and 12)were evaluated at a wind speed of 28 m/s.Parameters measured included:drag coefficient Cx,lift coefficient Cy,pitch moment coefficient Cm,center of pressure coefficient Cp,and the liftedrag ratio Cy/Cx,over a range of angle of attack(0e70).These coefficients were used in analyzing the differences in the performance among the three otter-board models.Results showed that the maximum lift coefficient Cy of the otter-board model with a main-panel angle of 0was highest(1.875 at a¼25).However,when the angle of attack was smaller(0<a<22.5),the lift coefficient of the otter-board increased as the angle of the main-panel increased.The maximum Cy/Cx of the otter-board with a main-panel angle of 12was highest(7.417 at a¼2.5),and the liftedrag ratio increased when the angle of the main-panel increased within the angle of attack at small angles(0<a<12.5).A comparative analysis of Cm and Cp showed that the stability of the otter-board with a main-panel angle of 0is better than those of the other models.Therefore,the comparative analysis of Cm and Cp,shows that a larger angle of the main-panel can reduce the stability of single-slotted otter-board.The findings of this study offer useful reference data for the structural optimization of otter-boards for trawling。展开更多
基金This work is financially supported by the National Key Technology R&D Program(Grant No.2013BAD13B03).
文摘The effect of the main-panel angle of a single-slotted cambered otter-board was investigated using engineering models in a wind tunnel.Three different angles(0,6,and 12)were evaluated at a wind speed of 28 m/s.Parameters measured included:drag coefficient Cx,lift coefficient Cy,pitch moment coefficient Cm,center of pressure coefficient Cp,and the liftedrag ratio Cy/Cx,over a range of angle of attack(0e70).These coefficients were used in analyzing the differences in the performance among the three otter-board models.Results showed that the maximum lift coefficient Cy of the otter-board model with a main-panel angle of 0was highest(1.875 at a¼25).However,when the angle of attack was smaller(0<a<22.5),the lift coefficient of the otter-board increased as the angle of the main-panel increased.The maximum Cy/Cx of the otter-board with a main-panel angle of 12was highest(7.417 at a¼2.5),and the liftedrag ratio increased when the angle of the main-panel increased within the angle of attack at small angles(0<a<12.5).A comparative analysis of Cm and Cp showed that the stability of the otter-board with a main-panel angle of 0is better than those of the other models.Therefore,the comparative analysis of Cm and Cp,shows that a larger angle of the main-panel can reduce the stability of single-slotted otter-board.The findings of this study offer useful reference data for the structural optimization of otter-boards for trawling。
