双桨船轴向伴流场尺度效应的数值研究

以DTMB5415为研究对象,忽略自由液面效应,采用RANS(Reynolds Averaged NavierStokes)方法结合SST(Shear-Stress Transport)k-ω模型计算了多种尺度(涵盖实尺度)的船舶黏性流场,详细分析了该船轴向伴流场的尺度效应作用.研究发现:桨盘面平均轴向伴流分数的倒数与雷诺数的对数近似线性关系;对于双桨方艉舰船的裸船体,桨盘面的伴流峰只有一个,伴流峰的幅值随着雷诺数的增加而减小,同时伴流峰所对应的相位角也发生一定的偏移.在内半径区域,伴流峰的幅值达到某一临界雷诺数后,趋于恒定不变;而在中外半径区域,伴流峰的幅值随着雷诺数的增加而减小,它们之间成非线性关系,可采用3次多项式函数进行回归;各半径的平均轴向伴流分数与雷诺数的对数成近似线性关系.

Numerical Study on Scale Effect of Axial Wake of Twin Screw Ship

Abstract： DTMB5415 was studied without considering free surface effect, the viscous flow fields of ship at different scales including full scale were solved numerically in RANS method and SST k ω turbulence model, and the scale effect of axial wake was analyzed in detail. It shows that the reciprocal of mean axial wake fraction of propeller disc exhibits a near linear dependence on Reynolds number in logarithmic scale. For the twin screw warship with transverse stern, only one wake peak exits. The amplitude of axial wake peak decreases with the increase of Reynolds number and the corresponding phase angle shifts at the same time. In the inner area of propeller disk, the amplitude of axial wake peak remains constant when the Reynolds number reaches a critical value. However, in the outer area, the amplitude of axial wake peak becomes smaller when the Reynolds number increases, and reveals nearly a cubic polynomial function dependence on the Reynolds number in the logarithmic scales. The reciprocal of mean axial wake at each radius reveals a nearly linear dependence on the Reynolds number in the logarithmic scales.