Assignment:
Question 1. An impulse air turbine has a total (on static) inlet pressure and temperature of 11,25 bar, 600 degrees K and exhausts to the atmosphere at 0.91 bar. The nozzle efficiency is 87% and its exit angle is 71 degrees. The rotor efficiency is 65%. If the blade speed if 190 m/s at the mean radius of 12cm, calculate the power output for full admission to the 2cm long rotor blades.
Question 2. It has been decided to use the following velocity diagrams for a STEAM reaction turbine stage which is expected to have a nozzle and rotor efficiency of 80% when the stage inlet total ((not static) pressure and temperature are 17 bar, 400 degrees C. Using the small segment of the enthalpy-entropy chart for steam that is suppled, plot the hs diagram for the nozzle and rotor and hence determine the outlet pressures of each.
Question 6. It has been decided to use the following velocities for a reaction turbine stage which is expected to have a nozzle efficiency of 90% and a rotor efficiency of 85% when the stage inlet total (not static) pressure and temperature are 5 bar, 1050 K. Calculate the as yet known velocities and then determine the specific work output and the outlet pressure from the rotor.
