In case of a four-screw ship, the propellers show different hydrodynamics performance due to the asymmetric distribution of the wake. And the particularity of the scale effect on wake field for this type of ship would make a more complicated characteristics on propeller bearing force. In this paper, a numerical simulation study of scale effect on propeller unsteady bearing force of a four-screw ship was performed by employing RANS method. The load variation of the single-blade is analyzed to understand the fluid mechanism of the interaction between the propeller blade and wake flow. The larger wake field difference between inside and outside propeller disk aggravates the unbalanced load distribution for the full-scale ship. The results of propeller bearing force highlight that the fluctuation values of full-scale ship are smaller than those of model one. Moreover, the scale effect of outside propeller is strong with respect to the inside one. The above findings can provide theoretical guidance for load balancing and vibration reduction of the four-screw ships.

在四螺杆船的情况下，由于尾流的不对称分布，螺旋桨显示出不同的流体动力学性能。这类船舶在尾流场上尺度效应的特殊性将使螺旋桨的受力特性更加复杂。本文采用RANS方法对四轴船螺旋桨非定常承载力的尺度效应进行了数值模拟研究。分析了单叶片的载荷变化，以了解螺旋桨叶片与尾流之间相互作用的流体机理。内外螺旋桨盘之间较大的尾流场差异加剧了全尺寸船舶的不平衡载荷分布。螺旋桨轴承力的结果表明，全尺寸船舶的波动值小于模型一的波动值。而且，外侧螺旋桨相对于内侧螺旋桨的比例效应很强。以上发现可为四螺杆船的载荷平衡和减振提供理论指导。