Simulation and Experimental Investigation of Low‐Speed Centrifugal Pump Coupled With Vertical Ultra‐Low‐Head Turbine for Small‐Scale Irrigation

ABSTRACT Traditional irrigation methods in Nepal are facing challenges and demanding alternatives in water pumping technology, including low‐scale irrigation. This novel research explores the design, simulation, fabrication, and testing of a low‐speed centrifugal pump (LSCP) to be coupled with a vertical ultra‐low‐head turbine (VULHT). This water‐powered pump delivers the same water used to run it. A simple test facility at the laboratory was developed using the newly designed LSCP driven with a DC motor in place of a VULHT. The variables are the tailwater level's control heights from 50 to 200 mm. The experiment conducted showed the maximum efficiency of 1.221% at 900 rpm at a control height of 200 mm with a delivery head of 1.6 m. The simulation results yielded a maximum delivery head of 1.87 m at 900 rpm for a 100 mm control height. The concept explored concluded that the low‐speed centrifugal pump was found to be inefficient for the tested conditions with this simplified design, and recommends developing an alternative principle for the design of a pump for ultra‐low‐head conditions different than centrifugal action.