Field Measurement On The Characteristics Of Flows With Submerged Rigid Vegetation And Numerical Simulation Of Lattice Boltzmann Method

Lattice Boltzmann Method(LBM)is a mesoscopic simulation method.It bases on fluid modeling,and has been developed in recent 30 years.Comparing with other methods in computational fluid dynamics.The method can easily run parallel calculation and adapt complex boundary.At present,Lattice Boltzmann Method has been widely used in the fields of flow and mass transfer for porous media,multiphase and multicomponent,interfacial dynamics,chemical reaction and transfer,etc.Meanwhile,Lattice Boltzmann Method also has a very large potential application-prospect in magnetic fluid,crystal formation,phase transformation-process,etc.Vegetational flow characteristics is a attention and research question.it is changing the whole ecosystem and affecting human life.Therefore,it is of great importance to study water flow problems of vegetation and understand the changing laws of water flow and other physical characteristics.The main work of this paper is to use lattice Boltzmann method to simulate the water flow problem with submerged rigid vegetation.Firstly,it is to add external force into the three-dimensional particle velocity D3Q19 model,and the complex boundary conditions and corner points of the fluid model were processed by heuristic scheme.Secondly,the model is established to simulate the square cavity flow of the classical numerical simulation case,and the feasibility of the model is verified by selecting different Reynolds Numbers and adopting single relaxation and multiple relaxation schemes for comparative analysis.Then,in order to compare with the qualitative rule of the simulation results,this paper conducted an experiment on water flow with submerged rigid vegetation.The water level and flow velocity were measured by three-dimensional laser doppler velocimeter,and a series of rules were summarized by analyzing the experimental results.Finally,with multiple relaxation time of D3Q19 model of a,a row and multiple row of vegetation,it is to simulate the flow experiments with a row and multiple row of vegetation,by using multiple relaxation time of D3Q19 model.And the simulation case is same as experiment conditions,it is include parallel arrangement with full-coverage,staggered arrangement with fullcoverage,parallel arrangement with semi-coverage and staggered arrangement with semicoverage,and there are four submergence values of the vegetation.The simulation results agree with the measured results qualitatively.In this paper,through a series of work,the D3Q19 model is well used to simulate the water flow with vegetation,and the simulation results accurately show the water flow state near vegetation,thus it is providing a strong theoretical basis for river flow management and water ecosystem restoration.