梭锥管与普通装置内水沙两相流场特性数值模拟

Numerical Simulation of Turbid Fluid Separation Device Separated from the Water-sediment Two Phase in Shuttle-conical Tube

采用层流方程和简化的多相流Mixture模型,针对结构尺寸相同的普通装置和梭锥管进行了浑水质量浓度为5 kg/m3的泥沙静水沉降的数值模拟,并将计算结果与PIV测量结果进行对比,计算结果与实测结果吻合较好.详细分析了两装置内速度场、浓度场的特点及区别.结果表明,在梭锥管内,泥沙通道中心断面上泥沙的速度是普通装置内的5～6倍;在相邻锥圈间形成了沿锥圈上表面向下和沿锥圈下表面向上的环流.在普通装置内,泥沙始终沿重力方向竖直向下沉降,泥沙浓度分布比较均匀,速度较小.与普通装置相比,泥沙在梭锥管中沉降的速度较快,且特有的结构—锥圈,改变了泥沙的沉降方向,缩短了沉降距离,增加了沉降面积,使梭锥管内的水沙分离效果更明显.因此,为了提高梭锥管内水沙分离的效率,可以适当增加梭锥管内的锥圈数量以增强其水沙分离性能.

Concentration of muddy water quality is 5 kg/m3 of sediment in still water settlement of shuttle-conical tube and ordinary device is simulated by using laminar equation and simplified mixture model.And the calculated results with the PIV measurement re sults were compared,the calculation results agree well with the measured data.A detailed analysis is made of the velocity field,the concentration field of the characteristics and differences in the two devices.The results show that in shuttle-conical tube,the speed of the sediment is 5-6 times of ordinary device in the sediment channel center section.Formed circulation that along the upper surface downward and along the lower surface upward between the adjacent conical circles.In ordinary devices,sediment always vertical downward subsidence along the gravity direction,concentration distribution is evener,speed is smaller.The settling velocity of sediment in the shuttle-conical tube with conical circles is faster than that in ordinary device.And the unique structure-conical circles,changes the direction of sediment settlement,reduces the settlement distance,increases the settlement area,and improves the settling velocity of sediment.Making the water-sediment separation effect is more obvious.Accordingly,in order to increase the settling ve locity of sediment,the number of conical circles should be raised so as to improve the separation of water and sediment in the shuttle -conical tube.