排沙漏斗流场的大涡模拟

Large Eddy Simulation of Flow in a Vortex Settling Chamber

排沙漏斗是一种截沙率高、冲沙耗水量小的新型的泥沙处理设施。为了得到全面详细的排沙漏斗流场结构信息,进一步探明排沙漏斗的排沙机理,采用大涡模拟和VOF方法,对排沙漏斗内水气两相流进行了3维数值模拟。计算的水流流速分布与用激光多普勒测速仪(LDA)所测得的试验结果基本一致。根据模拟结果对排沙漏斗内水流流速分布提出了一些新的认识。计算结果显示了排沙漏斗中二次流的特征,分析指出二次流是排沙漏斗能够顺畅高效排沙的关键。

The vortex settling chamber is an efficient and economical type of sediment extracting device.To obtain comprehensive information about the flow characteristics in vortex settling chamber,and to explore its working mechanism,the large eddy simulation model and VOF （volume of fluid） method were applied to simulate water-air two-phase flow in vortex settling chamber.The calculated results of average velocity were in good agreement with experimental data measured by Laser Doppler Velocimeter （LDV）.The simulation results gave some new understanding on the three-dimensional velocity distribution.Based on the calculation secondary flow was found clearly and it was critical for transporting and removing sediment efficiently in vortex settling chambers.