側岸侵食を伴う河道変動の数値解析

Abstract

This paper deals with the numerical analysis of channel processes resulted from bank erosion. In order to analyze the channel processes, it is necessary to develop a numerical model which is available to calculate unsteady open channel flow in a changing boundary with time. Therefore, a moving boundary fitted coordinate system was introduced to analyze the channel processes. The model is applied to compute the channel processes for the experiments with straight, circular and meandering channels. In the case of straight channels, the computed results were in good agreement with the experiments. In the case of circular channel, the model is improved to simulate the experimental results by introducing secondary flow component. In the case of the meandering channel, the volume of the bank erosion computed by the model is much smaller, and the probable reason of this discrepancy has been discussed based on the detailed experimental results of channel profiles and flow properties.