Research On Numerical Simulation Of Liquid Chemicals Diffusion By Meshless Nine-point Difference

With the increasing transportation of liquid chemicals in bulk by ships, the risk of the chemicals spill is getting higher and higher. Because of the difficulty of the callback of the chemical, it is more needed to take more exactly simulation to the action of the spilled chemical to reduce the environmental damage.So how to set up a rapid and exact numerical model is the key to reduce the risk.This paper summarizes the status of chemical transportation ,the environmental risk. and introduce briefly the status of administration of liquid chemicals in bulk. Through the analysis of the soluble chemical's behavior in water, set up the convection and diffusion model.To the solution of the advection and diffusion equations, this paper summarizes the development of meshless method and deduces the equations by meshless nine-point difference method. Based on the same method to calculate the tide-current, the numerical examples of rectangle and fanlike illustrate meshless nine-point difference has enough precision to the simulation of tide-current and contamination-current, easily fit to the irregular border and has rapid calculating speed and has simple pre-disposal.Furthermore, the thesis mainly shows the study on the advection and diffusion of soluble and conservative liquid chemicals in the water of Shanghai Port. Give the numerical simulations to the tide-current and contamination-current. The results shows that the numerical scheme proposed in this paper is valid and could be applied in actual forecast after further developing.