2-D Numerical Simulation of Flow in A Curved Open Channel

Bend flow is different from regular flow because of the existence of secondary flow which makes the bend flow much more complicated. As the secondary flow has significant influence on water flow, sediment transportation and river bed evolution, we take the secondary flow into account through the calculation of the dispersion stresses arisen from the integration of the products of the discrepancy between the mean and true velocity distributions. The orthogonal body-fitted coordinate is adopted to make the finite difference method applicable to irregular boundaries. The staggered grid system is adopted and the finite difference equations are solved by ADI method. We compare the numerical simulation results of 2D NS model with and without the consideration of the secondary flow to the measured data from a curved flume experiment. The results demonstrate that the model is in good agreement with the real flow and can well demonstrate the significant effects of the secondary flow in bend flow.