A single-stage impulse turbine has a mean blade diameter of 0.9m and a temperature drop of 250C
Question:
A single-stage impulse turbine has a mean blade diameter of 0.9m and a temperature drop of 250°C across the turbine at 9600 rpm when the gas flow is 28kgs -1. At the mean blade diameter, the absolute velocity of the gas leaving the rotor is 150ms -1. Find the inlet and outlet velocity angles of the gas to and from the rotor assuming that there is no residual whirl in the gas leaving the rotor and that the blade loss coefficient is 0.96. Intel and outlet velocities from the stage are the same.
Calculate the axial thrust on the stage and describe how this force is accommodated in the design of the rotor shaft. Explain the term velocity compounding and its application in impulse turbines. State any other assumption made. The specific heat capacity of the gas is 1017 Jkg -1 k -1.
Principles of heat transfer
ISBN: 978-0495667704
7th Edition
Authors: Frank Kreith, Raj M. Manglik, Mark S. Bohn