1) The impulse turbine having a set of 16 Nozzle receives steam at 20 bar, 400oC. Pressure of steam at exit is 12 bar. If total discharge is 260 kg/min and nozzle efficiency is 90%. Determine the cross sectional area of exit of each nozzle. If steam has a velocity of 80 m/s at entry to the nozzle, determine the % increase in discharge.
2) Air at the temperature of 300 K flows in the centrifugal compressor running at 18000 rpm. Other data given is as follows. Isentropic total head efficiency = 0.76
Outer diameter of blade tip = 550 mm
Slip factor = 0.82
Compute:
(a) the temperature rise of air passing through compressor
(b) the static pressure ratio suppose that the absolute velocities of air at inlet and exit of the compressor are same.
Take Cp = 1.005 KJ/kgoK.
3) The axial flow air compressor of 50% reaction design has blades with inlet and outlet of 45o and 10o respectively. Compressor is to generate a pressure ratio of 6:1 with the overall isentropic efficiency of 0.85 when air inlet temperature is 40oC. The blade speed and axial velocities are constant throughout the compressor. Suppose a value of 20 m/s for blade speed, determine the number of stage needed when the work factor is:
(a) unity (b) 0.89 for all stages.
4) Design sketches of horizontal axis wind turbines illustrating their main components. Describe their principles and write down its advantage and disadvantage.
5) Write a brief notes on Hydro-Dynamic power transmission:
a) Hydraulic Coupling
(b) application in Vehicles