3D Numerical Simulation Of Vortex Tube Sediment Escaping With Spiral Flow

Because of the high sediment discharge of river, lots of the sediments are moved into channels and lead to some serious problems such as turbine and pumping station equipment wearing out and channel siltation, which force pumping station shutdown and bring a great loss to the industrial and agricultural production. Vortex tube sediment escaping with spiral flow is a technique that removes the sediment from channels using the spiral flow produced by vortex tube at the bottom of a ditch, which is simply structured with high efficiency. Therefore, the research of vortex tube sediment escaping with spiral flow has a great practical significance in improving the life of the low-head hydropower station, solving the channel siltation problem and vortex tube design.The velocity distribution in vortex tube and vortex tube design are two important directions in the study of vortex tube sediment escaping with spiral flow and the research now is mainly based on the physical model test. In view of the long test cycle of the physical model, high cost and the shortage which can hardly obtain the complete flow field information, this article built the model and simulated the 3D numerical values of the vortex tube spiral flow pattern by using FLUENT. The simulation is Based on the SIMPLE method. Reynolds equation is closed with-kRNG ? turbulence model. Volume of fluid(VOF) method is adopted to track the free surface and the finite volume method is used to discretize the equations. The major work and conclusions of this paper are as follows:(1) Based on FLUENT, the 3D numerically model was established and got a stable flow field. By analyzing the information of flow field, the tangential and axial velocity distributions in vortex tubes were obtained and the conclusions of the vortex tube spiral flow field were made. Compared with the domestic and international documents and the results show that the numerical simulation is similar to experimental results.(2) Through the research of 3D numerical simulation of vortex tube sediment escaping with spiral flow in different conditions, the relations between the velocity distribution and channel slope, open angle of vortex tube, diameter of sand trapping tube and the angle between vortex tube and channel axis were analyzed in detail. Finally we got the most reasonable condition of vortex tube design.(3) The flow field was combined with Sediment particles by using DPM(Discrete Phase Model) and the movement of sediment particles were traced which showed the process that how sediment particle moving to the vortex tube from channel.