抄録
In this paper, the numerical simulation of flows in Lake Biwa with real configuration is presented in order to predict the large circulating currents. The effects of flow rate of inflow rivers and thermal convection on the large circulating currents are investigated. The observational flow rate and temperature data of inflow rivers are considered. First, the simulation of 2D epilimnion model is carried out, so that the results show that the large circulating currents are sensitive to the flow rate of inflow rivers. Next, the 3D flows with real configuration are simulated. The numerical results without thermal effect show that the precise large circulating currents are formed in summer, but the large circulating currents develop until winter. Finally, the 3D simulation with thermal convection is carried out. As a result, the horizontal circulating currents become larger than the simulation without thermal effect in summer, and the vertical circulating currents are formed in winter. Therefore, the present numerical simulation with thermal convection can reproduce the actual circulating currents in Lake Biwa qualitatively.
