Numerical Modeling of a Y-Bifurcator using Realizable k- e Turbulence Model

Abstract

In this paper, the outhors present the results of investigation on the influence of the boundary layer mesh size to the flow variable in the numerical of realbable k- e model in order to calculate the head loss offlow through a Y-bifurcator. This bifurcator is applied for combination of urbine and pumping operation in hydro plants. Five numerical models with difierent boundary layer mesh size was created and simulated for compared to the result of measurement on a physical model. At low Reynolds number region, the pressure head different and loss coeficient varies compare to the measurement. However it becomes closer to the measurement with increasing the Reynolds number. Wall treatment give good result for simulation in low Reynolds number. The pumping mode simulations produce better result in calculating loss coeficient for all Reynolds number regions than those in turbine mode simulation