Answer to Question #297238 in Mechanical Engineering for Rushikesh

Question

A single-stage impulse turbine rotor has a mean blade ring diameter of 500 mm and rotates at a speed of 10,000 rpm. The nozzle angle is 20° and the steam leaves the nozzles with a velocity of 900 m/s. The blades are equiangular and the blade friction factor is 0.85. Construct the velocity diagrams for the blades and determine the inlet angle of the blades for shockless entry of steam. Determine  (a) the diagram power for a steam flow of 750 kg/h,  (b) the diagram efficiency,  (c) the axial thrust, and (d) the loss of kinetic energy due to friction.

Answer 1

The single-stage impulse turbine is also called the de Laval turbine after its inventor. The turbine is made up of a single rotor with impulse blades attached to it. The steam is fed through one or more convergent-divergent nozzles that do not extend entirely around the circumference of the rotor, allowing the steam to impinge on only a portion of the blades at any given time. The nozzles can be put ON or Off to improve partial flow performance.