船舶螺旋桨射流扰动下的污染底泥起悬研究

河流、湖泊中船舶的航行对于水体底部的污染沉积物具有很强的扰动作用,特别是船舶尾部的螺旋桨射流。通过一个新近提出的射流速度分布统一公式,结合考虑底泥的起动、冲刷特性,进行船舶螺旋桨射流扰动下污染底泥起悬的计算研究。结果表明,螺旋桨距河流底面的深度、螺旋桨射流出口流速、螺旋桨直径对底部流速的分布影响显著;同时发现,周围水体流动方向及流速等对于底泥扰动范围也有显著影响;最后定量计算了螺旋桨作用下污染底泥扰动悬浮速率。

Resuspension of Contaminated Bottom Sediment on Disturbing of Boat Propeller Jet Flow

Contaminated bottom sediment in water system was apt to be disturbed by navigation, especially by propeller jet flow behind the boats. By simulating calculation with a new velocity distribution formula of free jet flow and a scour rate one, the resuspension of contaminated bottom sediment on the disturbing of boat propeller jet flow was studied. Results showed that the height of propeller from bottom sediment, water velocity on the jet exit, diameter of propeller are main factors acting on flow velocity on the bottom plane. Environmental flow direction and velocity also obviously affected on the disturbing scope of jet flow. Finally, resuspension rate of contaminated bottom sediment on the action of propeller jet flow was calculated quantitively.