Three-dimensional numerical simulation for an open channel flow with a constriction

Flow characteristics in an open channel with a constriction are investigate d numerically by using a three-dimensional multi-level hydrodynamic model. In this model. the two-step Euler predictor-corrector algorithm is introduc ed to predict and correct free surface water level. The momentum equations in horizontal directions are discretized in an explicit scheme for the comp onent velocities u and v, and the continuity equation is discretized for th e velocity w in an implicit scheme in uniform and non-uniform grid systems. The model has been tested against analytical solutions for two standard ca ses and used to study sudden contraction and expansion open channel flow. T he numerical results are in good agreement with analytical and experimental data. Simulated flow patterns for the sudden contraction and expansion flo w show reasonable flow characteristics downstream of an opening.