A radically inward flow turbine working under a head of 10 m and running at 250 rpm develops 185 KW at the turbine shaft. At inlet tip of the runner vane, the peripheral velocity of the wheel is 0.9.√2gH and radial velocity of flow is 0.3.√2.gH; when H is the effective head on the turbine,. If overall efficiency of turbine is 78% and hydraulic losses amount to 12% of total head, Calculate :-
(i) Diameter of runner and its width at inlet.
(ii) Guide blade angle at which water is directed to runner.
(iii) Inlet angle of the runner vane.
Consider that turbine is a reaction one with radial discharge at outlet. The following data pertains to an inward flow reaction turbine :
Net head = 60m; speed = 650rpm; break power = 275 KW;
Ratio of wheel width to wheel diameter at inlet = 0.10; Ratio of inner diameter to outer
diameter = 0.50; flow ratio (Kf) = 0.17; ηh = 0.95; ηo = 0.85.
The Flow velocity remains constant and discharge is radial. Neglect the area blockage by blades, work done that dimensions and blad angles of turbine.