导管桨与竖直壁面间距对尾流特性影响的PIV试验研究

PIV Experimental study on influence of vertical wall on wake of ducted propeller

随着现代化大型船舶的高速发展,港口和码头受到日益增大的螺旋桨尾流冲刷影响,而广泛应用于重载船舶上的导管桨对码头岸壁所造成的冲刷破坏更为严重。该文应用自主搭建的2D-2C PIV及2D-3C PIV系统,以KA4-70+19A导管桨为研究对象,测量了导管桨在距离竖直壁面1D-4D系泊工况下的轴向切面二维流场及横向近壁面处的三维流场。结果表明:导管桨尾流在到达壁面后,沿壁面向四周流动,壁面中心处会形成一个低速的圆锥形区域;流体沿着圆锥形外侧到内侧循环流动,形成漩涡,其大小随着导管桨与壁面距离的增大,呈先增大后减小趋势,外侧尾流带动圆锥形低速区的运动,而圆锥形低速区又对前方尾流造成影响。

With the rapid development of modern large ships,ports and wharfs are affected by increasing scouring of propeller wakes.The scouring damage caused by duct propellers which is widely used on heavy-lift ships is more serious.In this paper,KA4-70+19A ducted propeller two-dimensional axial tangential flow field and three-dimensional transverse flow field at 1 D-4 D vertical wall distances are measured by using self-constructed 2D-2C PIV and 2D-3C PIV systems.The results show when the wake reaching the wall,it flows around the wall,forming a conical low speed area at the center of the wall.The fluid circulates from the outside to the inside of the cone to form a swirl,the scale of conical increases first and then decreases as the distance between the duct propeller and the wall increases.The outer wake drives the movement of the conical lowspeed zone,which in turn affects the front wake.