Question

The impulse turbine rotor efficiency will have a maximum value of 0.5 cos2 α, where α is the nozzle exit flow angle, if the
A. blades are equiangular
B. blade velocity coefficient is unity
C. blades are equiangular and frictionless
D. blade solidity is 0.65

Answer 1

Following the principles of Parson’s reaction turbine we conclude the efficiency of impulse turbine rotor will be of value 0.5 cos2 a

where “a” is the flow angle of nozzle exit provided the blades are having the same angler and are friction less.

 It is clearly visible in the reaction turbine diagram and the flow of steam due to acceleration.