Two-dimensional Water Quality Numerical Simulation Of The River

The environment quality is greatly impacted by our living style,and the water quality is the most important issue of the environment fluid dynamics,based on the environmental fluid dynamics (CCF) and using CFD,a simulation method of contamination concentration field of river is proposed in this paper and then it is applied to simulate water quality of some section of Yangtze River and Jialing River around Chongqing city.The water quality simulation and forecast is the important domain of environment hydromechanics. With the development of computer science and technology,2D and 3D water quality models have become effective. And in the currency water quality models,such as QUALII,the ingredient of water quality are always separately treated,in this paper too. In another hand any river is divided into flow tubes,and we can applied FVM to the flow tubes according to mass conservation principle and established the finite volume model in CCF.As most of the calculation of hydromechanics,ours is based on Bernoulli equation. We subdivided a river,drawn its flux cumulative graphics and divided flow tubes,then calculated the parameters that is described in Chapter 3 in details.Taking a flow tube as a finite volume and drawing finite volume mesh in the CCF. We can establish the 2D water quality model which is convection-diffuse equation,and use the operator splitting method to solve it. To avoid the limit of grid Reynolds number,the Upwind Scheme is used. For appropriate time-space step length and well-posed initial and boundary conditions,the information of 2D water quality evolution can be simulated. Comparing our results with the simulation of the Chongqing Institute of Environment d Science Research and the Chongqing Architecture University in 1989,it shows that our method is valid.In this paper we completed a combination of the flowing tube method and the operator splitting method with FVM,and then applied it to simulate 2D water quality of some sections of Yangtze River and Jialing River around Chongqing city. The numerical simulations show this method is simple and has good precision. It can be applied to the shallow river such as Yangtze River and Jialing River.