Development of a Numerical Model for Predicting Dynamic Pressures in Open Channel Flow using Non-Orthogonal Curvilinear Coordinate Grid

Document Type : Research Article



A 2DV numerical model is developed for solving unsteady Navier-Stokes equations with the ability
for calculating dynamic pressures in non-orthogonal curvilinear coordinate grids for free surface
flows. The model is based on fractional step method (or projection method). The free surface elevation
is calculated using continuity equation. The present method uses the advantages of shallow water
models for calculating free surface elevation (even in cases with large changes) and benefits the
flexibility of moving non-orthogonal grids. Moreover, this method presents the ability of developing a
shallow water solver to take into account the dynamic pressures.
The simulation of water elevation in a gradually varied flow, showed the ability of mesh adaption in
moving and curved boundaries. Comparing the results of the model with experimental data and other
numerical models, for flow passing over a hump and trench, confirms the ability of the developed
model for simulating the free surface flows. Having the ability of calculating free surface and dynamic
pressures, the model can therefore be applied to rapidly varied flows.