A 2D Numerical Depth-averaged Model for Unsteady Flow in Open Channel Bends

The purpose of this paper is to present a 2d depth-averaged model for simulating andexamining unsteady flow patterns in open channel bends. in particular, this paperproposes a 2d depth-averaged model that takes into account the influence of thesecondary flow phenomenon through calculation of the dispersion stresses. the dispersionterms which arose from the integration of the product of the discrepancy between themean and the actual vertical velocity distribution were included in the momentumequations in order to take into account the effect of the secondary current. this modelused a time-splitting method for solving advection, diffusion and other momentumequation terms. the proposed model uses an orthogonal curvilinear coordinate systemefficiently and accurately to simulate the flow field with irregular boundaries; it also useda finite volume projection method approach for solving the governing equation in astaggered grid. two sets of experimental data were used to demonstrate the model'scapabilities. the comparison of the simulated water surface elevation with themeasurements shows good agreement and indicates that inclusion of the dispersion termsimproved the simulation results.