Numerical Characterization of the Effects of Flow Rate on Pressure and Velocity Distribution of Pump as Turbine

Small hydropower systems are the best solution for electromechanical components through the use of pump operating at inverse conditions as turbine for power generation in rural settlements of under developed countries especially since its construction and maintenance is cheap. This study investigates the effects of flow rate and internal flow characterization of a model centrifugal pump operating at a rotational speed of n = 1400 rpm with 4 main blades and 4 splitters at a head of 18 (m) and flow of 12.5 (m³/h). The experiment and numerical calculations were performed, and pressure and velocity were analysed based on the results obtained. According to the results obtained, velocity increased by movement of flow through the flow passage. As the discharge increased, head decreased but the power required to run the pump increased. Centrifugal pump can perform in reverse mode as a hydro turbine devoid of any modification on mechanical components with a maximum efficiency of 62.07% recorded at Q = 20 m³/h. The study helps to recognize the numerical flow characterization and serves as a supporting document to provide vital information on centrifugal pumps to other studies.