3-D NUMERICAL SIMULATION ON RESPONSE OF VELOCITY AND WATER LEVEL IN FLOOD FLOW AGAINST WIND STRESS OF STORM CONDITIONS

Abstract

 This study aims to obtain basic knowledge on the hydraulic characteristics of flood flows under storm conditions in order to examine the risk of simultaneous occurrence of floods and storms in rivers due to super typhoons. We conducted simple numerical experiments for flood flow in straight channel with uniform cross section under various wind speed and directions. The results indicate that after the onset of wind stress, the flow velocity in the main flow direction changes abruptly, reaches a maximum value, and then transitions to a steady state. The response of flow velocity to wind stress was faster than the response of water level due to the large vertical mixing modeled with vertical kinematic eddy viscosity.