The pressure rise, Ap across a centrifugal pump from a given manufacture can be expected to depend on the angular velocity of the impeller w, the Diameter D, of the impeller, the volume flow-rate Q, and the density of the fluid, p. By using the method of repeating variables show that Ар pw² D² wD³ A model pump having an impeller diameter of 0.200 m is tested in the laboratory using water. The pressure rise when tested at an angular velocity of 407 rad/sec is shown on the graph. What would be the pressure rise for a geometrically similar pump with an impeller diameter of 0.30 m used to pump water operating at an angular velocity of 80% rad/sec and at a flow rate of 0.070 m³/s? Sol:

A wind turbine gives the following data: Blade length= 55.5 m. Wind speed = 11 m/s Air density = 1.227 Kg/m3 Power coefficient = 0.55 Assuming equal efficiencies for gearbox and generator, If the Power output from wind turbine, P is 2.1 MW, then find a) Rotor Power Output, P- in M (* b) Wind Power, Pw in MW (: C) Efficiency of Generator Rotor Power Output, Pr in MW