SIMULATION METHOD OF INSTANTANEOUS INJECTION FOR NUMERICAL SIMULATION OF POLLUTANT MIXING IN THE RIVER

摘要

A method for simulating instantaneous injection in numerical analysis of pollutant diffusion in a river is provided to perform more efficient and definite simulation of the instantaneous injection by describing injection conditions with generation terms using temporal & spatial delta functions and constructing a numerical model based on an FEM(Finite Element Method). A method for simulating instantaneous injection includes the following several steps. An FEM is applied to a two dimensional advection-dispersion equation for constructing a two dimensional numerical model, and a weighted residual method is applied to the advection-dispersion equation in an applied area. The Green's theorem is applied to the result of the prior step, and the second derivative included in an extended term is converted into the first derivative. Depth averaged concentration is interpolated with a linear shape function. Integral calculus is performed with respect to time by using an average value theorem while using a finite integration method which performs integral calculus for a discrete time in order to process a temporal differential term.