Question 1
1.1 Assuming a constant radial velocity of 2.8 m/s, a centrifugal pump impeller with an internal and exterior diameter of 0.20 m and 0.4 m, respectively, runs at 1500 rpm. The vanes at the exit are set back at an angle of 30°. Determine the angle the water's absolute velocity at the exit makes using the tangent, the angle of the inlet vane, and the amount of work per kilogram of water. (20)
1.2 A centrifugal pump's impeller has an outside diameter of 1.06 meters and a speed of 56 meters per second. The blades have a 20° angle with the wheel tangent at the blade tip due to their backward curvature. If the slip factor is 0.88 and the flow's radial velocity at the tip is 7.5 m/s. Ascertain the fluid's absolute velocity at the impeller as well as the real work input per kilogram of water flow. (15)
[30]
Question 2
2.1 With a head of 5.5 meters, a Kaplan runner can generate 9000kW. Assume 2.08 as the speed ratio, 0.68 as the flow ratio, and 85% as the mechanical efficiency. The diameter of the hub is one-third that of the runner. Determine the runner's diameter, speed, and specific speed. (15)
2.2 An outward flow reaction turbine wheel has inner and outer diameters of one meter and two meters, respectively. At an angle of 20°, the water enters the vane and exits it radially. Determine the vane angles at the inlet and exit. If the wheel revolves at 290 rpm and the flow velocity stays constant at 12 m/s. (10)