Abstract
A new three-dimensional numerical method for large-scale river flow with a new mode-splitting technique and a parallel computation is developed. To remove the severe limitation of the computational time interval for the 3D calculation in previous mode-splitting techniques, we present a new mode-splitting technique with satisfying high numerical stability and reducing computational time. To examine the fundamental performance of the present model, the 3D computations of unsteady flows in straight and curved open channels are performed, showing that the present model may have high numerical accuracy and appreciable computational efficiency. The present model is also applied to the flood flow computation in the Edo River. The good agreements are obtained between the model simulation and field measurements. More importantly the computational time of the present model amounts to only 0.4% of that of the normal 3D model without the mode-splitting technique.
