易淤船坞推水式清淤装置的水动力数值仿真研究

Numerical Simulation about Hydrodynamic Performance of Pushing-waterDredging Device Used in Silted Drydock

地处长三角地区的修船厂,沿岸海水的含沙量大,每次船舶进出坞都会造成较严重的坞内泥沙淤积,若采用传统高压水冲洗清淤方法,会因耗时较长而影响船坞使用效率。开展易淤船坞高效水动力清淤的数值仿真研究具有较好的实际工程应用价值。该文根据高含沙水体基本特性,基于光滑粒子动力学法和非牛顿沙相流变模型,考虑运动推板与积水和沉沙间的联动作用,实施推水式清淤装置对易淤船坞水动力清淤效果数值仿真研究。系统分析折弯角度等结构参数对折线形推水板的清淤面积、体积、速率、推板阻力及单位功率清淤体积的影响。研究表明,推板的推动作用可有效促进板前高浓度流质以波浪形式向外侧扩散,推水式水动力清淤方法可大幅提高水体的携沙能力,促进淤沙随水体迅速排出船坞,有效解决了船坞的快速清淤问题。直推水板具有最佳清淤效果,但其消耗功率亦最大;100°折弯角度的折线形推水板具有95%以上的有效清淤面积,且单位功率清淤体积高于其他推板,是适合船坞清淤的折线推水板构型。

The sediment concentration outside the shipyards located around the Yangtze River Delta is commonly high.It usually causes serious sediment deposition in the drydock when ships enter and leave the drydock.It costs a long time using the traditional dredging method via high-pressure water jet,leading to low service efficiency of drydock.Therefore,it has great practical value to carry out numerical simulation research on high-efficiency hydrodynamic desilting in the silted drydock.According to the basic characteristics of hyper-concentrated water,and based on the smooth particle dynamics(SPH)method and the non-Newtonian rheological model,the simulation study on the dredging effect of pushing-water plate is carried out,taking into account the interaction among water,sediment and moving plate.The influence of structural parameters such as bending angle on the desilting area,desilting volume,desilting rate,average drag force and unit power desilting volume of pushing-water plate is systematically analyzed.It shows that the pushing action of the pushing-water plate can effectively promote the diffusion of high concentration fluid in the form of wave.The hydrodynamic dredging method via pushing-water dredging device is helpful to improve the water transport capacity.It promotes the sediment discharging process from the drydock.It is bound to be an effective way to the issues related to quick dredging in drydocks.It is proved that the straight pushing-water plate has the best desilting effect,but its energy consumption is considerably large.The pushing-water plate with bending angle of 100 degrees is the optimal shape with more than 95%effective desilting area and highest unit power desilting volume.