螺旋桨诱导的船体表面脉动压力数值预报

Numerical Prediction of Pressure Fluctuation Included by Propeller on Hull Surface

基于RANS方法,采用滑移网格技术建立"船+桨"计算模型对双尾客船的螺旋桨诱导的脉动压力进行了数值预报.对比不同航速下船模阻力试验值与计算值,发现二者吻合良好,计算精度较高,说明了计算模型的可靠性;重点分析了船底板脉动压力沿船长方向及船宽方向的分布规律,发现最大脉动压力分别发生在桨盘面前方0.1 D处以及桨轴心线右侧0.05 D处,且脉动压力沿船长方向衰减速度较船宽方向更快,而在船宽方向的作用范围较船长方向更广;分别探讨了不同梢隙比、不同转速、不同航速下脉动压力的变化规律.研究表明,脉动压力一阶幅值是该船后螺旋桨诱导脉动压力的主要成分,增加梢隙比、减小螺旋桨转速,以及增加航速均会降低螺旋桨诱导的脉动压力.

By using Reynolds-Averaged Navier-Stokes（RANS）equations,a ship-propeller model based on sliding mesh method is performed to numerically predict the propeller-induced pressure fluctuation for a double-stern passenger ship.It is found that hull resistances are predicted fairly well compared to the experimental results under different speeds,which validates the calculation models.The distribution of pressure fluctuation on hull bottom is analyzed in detail.Results show that the maximum of pressure fluctuation occurs at 0.1Din front of propeller disk in the direction of length,and 0.05 Dto the right of propeller shaft axis in the direction of width.The pressure fluctuation decreases faster in the direction of length,while it presents a wider influencing scope in the direction of width.The variation laws of pressure fluctuation are discussed under series of tip clearance ratios,rotational velocities and ship speeds,respectively.The results show that the first-order amplitude of pressure fluctuation is dominant.In addition,the increase of tip clearance ratio and speed of the ship and the reduction of rotational velocity of propeller can lower the induced pressure fluctuations.