A centrifugal pump is to be used to pump water at a rate of 50 L/s from a sump to a storage reservoir, where the water surface in the storage reservoir is 25 m higher than the water surface in the...

A centrifugal pump is to be used to pump water at a rate of 50 L/s from a sump to a storage reservoir, where the water surface in the storage reservoir is 25 m higher than the water surface in the sump. The suction and discharge line from the pump have a total length of 48 m, a diameter of 125 mm, and an estimated roughness height of 0.5 mm. The sum of the local loss coefficients in the pipeline is equal to 4, the specific speed of the pump is 0.8, and the manometric efficiency of the pump is 80%. In the homologous series from which the pump is selected, the impeller blades are forward-curved and make an angle of 55◦ with the outflow surface, the width of the impeller is equal to 12.5% of the diameter, and the blades cover 7% of the outer area of the impeller. Inflow to the impeller is normal to the inflow surface. What size impeller should be selected for this application? Assume water at 20◦C.