抓斗下降时的流场和最优下降方式的数值计算（摘要）

龙瑞1，Tomoaki NAKAMURA2，Yonghwan CHO2，Norimi MIZUTANI2，Tsuyoshi KANAZAWA3

（1.长江科学院河流研究所，湖北　武汉　430010；2.Nagoya University，Nagoya 464-8603，Japan；3.TOYO CONSTRUCTION CO.，LTD.，Hyogo 663-8142，Japan）

【摘 要】 疏浚作业时如何能有效减少水体浑浊，减轻污染一直是人们关注的问题。本文利用可以分析流体和固体间运动相互作用的FS3M数学模型，模拟了环保型抓斗下降过程中的流场情况并讨论了不同下降方式对流场的影响，提出了能适度控制流场扰动的操作方法。结果表明抓斗在下降过程中减速能有效减少底面流速，达到抑制底面浑浊的效果，其中抓斗在距离底面3m处减速为初始速度的1/3能最有效地减少水体扰动从而抑制底面浑浊。

【关键词】 疏浚；抓斗；下降作业；流场；数值计算

Numerical Calculation of Flow Field and Optimal Operation during the Drop of Grab Bucket(www.zuozong.com)

LONG Rui1，Tomoaki NAKAMURA2，Yonghwan CHO2，Norimi MIZUTANI2，Tsuyoshi KANAZAWA3

（1.River Department，Changjiang River Scientific Research Institute，Wuhan Hubei Province 430010，China；2.Nagoya University，Nagoya 464-8603，Japan；3.TOYO CONSTRUCTION CO.，LTD.，Hyogo 663-8142，Japan）

Abstract：It is essential to effectively reduce the generation of turbidity and pollution in dredging works.In this paper，flow field during the drop of a sealed grab bucket was analyzed with a three-dimensional coupled fluid-structure-sediment-seabed interaction model（FS3M），and the impact of different drop modes on turbidity was discussed in order to propose the optimal drop operation for reducing the turbidity effectively.Numerical results showed that a decrease in the drop speed of the bucket can effectively reduce flow velocity at the bottom，suggesting a reduction in the generation of turbidity from the bottom.In particular，it was found to be the most effective to reduce the drop speed of the grab bucket to one-third when it approached 3m from the bottom.

Key words：Dredging；Grab Bucket；Drop Operation；Flow Field；Numerical Analysis