Test: Pelton Turbine - Civil Engineering (CE) MCQ

By using velocity triangles we can determine discharge of flow, angle of deflection of jet and to measure relative velocity of jet with respect to speed of wheel.

Usually velocity of blade is given by u = radius x angular velocity from which velocity is proportional to speed of wheel.

In Pelton turbine velocity of inlet is parallel to splitter and is parallel to x axis which doesn’t have flow velocity.

By constructing velocity triangle we come to know that whirl velocity of jet is equal in magnitude to that of Blade velocity – x- component of V (r₂).

In Pelton turbine, inlet velocity of jet and velocity of vanes are in same direction and of different magnitude hence relative velocity is found by calculating its difference.

In Pelton turbine the energy available at inlet of runner that is at outlet of nozzle is known as runner power, the energy available in penstock is water energy.

Coefficient of velocity is defined as ratio of actual velocity of jet at vena contraction to theoretical velocity. Its value is approximate to 0.98.

In Pelton turbine each blade has same angular velocity and same linear speed unlike Francis and Kaplan turbines.

It is standard value for deflection of jet, which is found by performing several experimental operations.

Runner power is less when compared with power available at exit of nozzle due to frictional losses.