In this article, flow patterns in a channel with a side concavity are studied numerically. The twodimensional depth-averaged saint venant equations, including the turbulence terms, are solved. The algorithm applies the finite volume method of Roe-TVD with unstructured triangular cells. Three depthaveraged turbulence models, including the mixing length, k  and algebraic stress model (ASM) are used to close the hydrodynamic equations. The numerical results are compared with the available numerical and experimental data. It is clearly shown that the two-dimensional finite volume method of Roe-TVD using the shallow water equations can estimate the flow depth variations and vortices in a side concavity, successfully. It is concluded that by increasing the aspect ratio the water depth enhances within the concavity section and the finite volume method of Roe-TVD with the ASM gives the best results.

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