短波中标称伴流场特性分析

The Analysis of Nominal Wake Flow Characteristics in Short Wave

以KCS标准船型为研究对象,采用RANS(Reynolds Averaged Navier-Stokes)方法对KCS约束模型在规则短波航行下标称伴流场进行了数值计算,并针对标称伴流场在短波中时历周期性变化的规律和特性进行了分析.计算结果表明:短波顶浪下的轴向标称伴流分数满足与入射波相似的周期性变化规律,单个波浪遭遇周期下的波浪伴流分数变化占比相对较小,但影响不可忽略;波浪伴流分数为负值时其主要原因为流体质点发生沿波浪传递方向的波漂移,其值近似为总平均流量;当波峰波谷位于螺旋桨盘面处时,轴向标称伴流场变化最为明显,且变化程度受波陡影响最大,而波长的减小对桨盘面下方区域的影响更为明显.

KCS standard ship model was studied as the object of this paper. The numerical calculation by using Reynolds Averaged Navier-Stokes method is mainly for the variation of the constraint model’s nominal wake field in a short regular wave encounter period, and its features are analyzed. The calculation results show that time history of axial nominal wake fraction is the same as the periodic variation of the incident wave. The variation of the wave wake fraction in a single wave period is relatively small, however, the impact of wave cannot be ignored. The main cause of wave wake fraction in negative value is the wave drift in the direction of the wave direction, which approximately equals to the total average flow. When the wave crest and wave trough is located at the propeller disk, axial nominal wake field change is always the most obvious, and the degree of change significantly affected by the wave steepness, and the decreases of wave length has a certain influence on the below of the propeller disk.