A Pelton wheel turbine is illustrated below The radius to th

A Pelton wheel turbine is illustrated below. The radius to the line of action of the tangential reaction force on each vane is 1 ft. Each vane deflects fluid by an angle of 135° as indicated. Assume all of the flow occurs in a horizontal plane. Each of the four jets shown strikes a vane with a velocity of 100 ft/s and a stream diameter of 1 inch. The magnitude of the velocity of the jet remains constant along the vane surface. a) How much torque is required to hold the wheel stationary? b) How fast will the wheel rotate if shaft torque is negligible, and what practical situation is simulated by the condition?

Solution

In given problem jet enters at velocity of (V)100ft/ses and while travelling velocity also remains same means its Outlet velocity (u)=100ft/sec

Force =(rho)*A(V-U)sinQ

V=U=0.............velocity remains same, there is no any trasfer to wheel

its means no torqua requires to hold wheel and wheel remains staotinary