Performance prediction of a centrifugal pump working in direct and reverse mode using Computational Fluid Dynamics

The operation of centrifugal pumps as centripetal turbines can be useful to produce cheap energy in rural zones or developing nations. However, the optimum coupling between the flow and the geometry of the machine cannot be kept in reverse working conditions, and hence the flow instabilities are expected to be much higher. This paper presents a numerical investigation on the unsteady flow in a commercial centrifugal pump operating in direct (pump) and reverse (turbine) mode. Numerical simulations were conducted for several flow rates to investigate the properties of the global flow within the machine. The numerical model was additionally used to estimate the radial load on the impeller, as a function of flow rate, for both modes of operation.