Upgrade of PCFLOW2D model with k-e turbulence model for unsteady flow

This thesis presents basic mathematical models used in calculation of turbulent flows worldwide. We\ud upgraded the PCFLOW2D program with the Smagorinsky model and the k-�à turbulence model for unsteady flow. PCFLOW2D is derived from the TEACH program and is written in the Fortran 77 programming language. PCFLOW2D is a two-dimensional depth-averaged model which calculates turbulent flow in open channels. It uses finite volume method of Patankar and Spalding to calculate partial differential equations for unsteady flow. We utilised our upgrades on the mathematical model with hybrid numerical scheme to calculate unsteady flow in a laboratory channel with a side discharge and on a kayaking track on the river So.a near Solkan. Both study cases were calculated using the\ud model of constant effective viscosity, the Smagorinsky model and the k-�à model and the results were compared. Analysis shows that while the new model works, it has some problems with numerical diffusion. It produces physically realistic results, with insufficient length of recirculation, due to increased numerical diffusion. We attempted to solve the problem by condensing the numerical grid, but were unable to entirely remove the numerical diffusion. We also tested an up-to-date Fortran compiler, PGI Visual Fortran, that compared to the current compiler, reduced computational times by 45% on average