Numerical study of the influence of Geometrical Parameters on flow in water Pump-Sump

Abstract

Water for irrigation, domestic and industrial supply as well for some power generation is normally drawn directly from rivers or from reservoir through sumps. The flow at the pump section sump may have large effects on the pump performances and the operating conditions. The flow patterns in the sump are mainly determined by the shape and scale of the sump. However, it’s not always possible to design a sump pump to provide uniform and stable flow to pumps, due to site constraints. For example in some cases air entraining (surface and subsurface vortex) occurs. These vortices may reduce pump performances and lead to increase plant operating costs. It becomes essential to investigate the pump sump to avoid these non uniformities inlet flow problems. Two approaches (experimental and numerical) are generally followed for such investigation. The numerical approach usually used solves the Reynolds averaged Navier-Stokes (RANS) equations with a near-wall turbulence model. In the validation of this numerical model, emphasis was placed on the prediction of the number, the location, the size and the strength of the various types of vortices. A previous study done by the same hauteur of this one [1], has shown the influence on a single type of mesh with different cell numbers, different intake pipe depths and different water levels, for two turbulence models closure. The present paper mainly focuses, first, on the effect of pump intake location in the sump and secondly on the effect of several inlet velocity gradients at inlet sump section.