螺旋桨洗流在实体式码头前沿砂质海床上的间歇冲刷试验研究

Experimental study on intermittent propeller wash scour near solid wharf on the sandy seabed

随着高功率发动机在船舶上的使用以及船舶机动性能的提高,螺旋桨洗流在实体式建筑物周围的冲刷正逐渐成为冲刷研究的重要内容之一。首先自行研发了一套一体化试验设备,之后利用该设备进行了螺旋桨洗流对实体式码头砂质海床的间歇性冲刷试验研究。通过对d_(50)=0.7 mm的原型砂土海床的间歇冲刷试验发现:在同等试验条件下,与连续冲刷相比,间歇冲刷会加深冲刷坑的深度,加深范围介于1.3%~24.8%;间歇冲刷时单次冲刷时间长度越短,冲刷次数越多,冲刷深度加深的越明显;且随着螺旋桨到码头面距离的增大,间歇冲刷引起的冲刷深度的增加越明显。最后提出了最大间歇冲刷深度的定量预测方法,该方法可为实体式码头前沿砂质海床的间歇冲刷防护提供理论支撑。

With the use of high power engine on the ship and the improvement of ship performance, the scour of propeller washing around the solid building is becoming one of the important parts of the washing research. Firsily, a set of integrated test equipment was developed in this paper. Then the study on the intermittent scouring of the d50 = 0. 7 mm-sandy seabed near the solid quay was carried out by using the equipment. It is found that the ultimate scour depth in intermittent souring is deep in comparison with continuous scouring, and the deepening range is from 1.3% to 24.8% under the same experimental conditions. The scour depth is deeper when the length of a single scouring time is shorter and scour times are more. And the larger the distance from the propeller to the wharf surface is, the greater the increase of scour depth caused by intermittent scour is. Finally, a method for quantitative prediction of intermittent scour depth was proposed to provide the theoretical support for the protection against intermittent scour on the sandy seabed near the solid wharf.