斜流中船后螺旋桨水动力载荷实尺度计算分析

CFD analysis of hydrodynamic forces for full-scale hull-propeller in oblique flow

斜流条件下螺旋桨可能受到较大的侧向载荷,会严重影响船舶推进效率和尾轴的安全。本文采用RANS(Reynolds-Averaged Navier Stokes)方法,结合SST k-ω两方程湍流模型和滑动网格方法,对国际标模KCS斜流中船后螺旋桨水动力载荷进行实尺度数值计算,分析不同漂角时螺旋桨在纵向、横向、垂向3个方向上的力和力矩的变化规律。计算考虑±20°,±15°,±10°,±5°以及0°漂角,结果表明斜流对螺旋桨推进载荷和侧向载荷都有较大影响,且相对漂角具有不对称特点。通过单独桨叶的推力变化曲线分析漂角对不同相位角度处螺旋桨载荷的影响规律,结果显示在桨盘面下端附近桨叶载荷更为敏感于漂角变化。通过与其他文献数据对比,分析斜流下螺旋桨载荷的尺度效应,结果表明轴向载荷和垂向载荷系数的尺度效应较大。

Large propeller lateral loads may be generated under oblique flow condition,which is critical to the safety of stern tube bearing of a ship.In the present study,the effect of oblique flow on full-scale hull-propeller hydrodynamic forces is numerically investigated based on RANS method,coupled with SST k-ωturbulent model and sliding mesh method.Analysis is carried out on the hydrodynamic forces and moments of propeller at axial,lateral and vertical directions,.The drift angles of±20°,±10° and 0° are taken into account in the caculation.The results show that oblique flow has a great influence on propeller propulsion load and lateral load,and the relative drift angle is asymmetric.The influence of drift angle on the propeller load at different phase angles is analyzed through Periodic single blade thrusts at different drift angles.The results show that the oblique flow has a larger effect on the blade load below the propeller center.Compared with other literature data,the scale effect is also investigatedthe.It is revealed that the scale effect of horizontal and vertical loads is large.