Solve the following:
Q: A turbine blade 5-cm long, with cross-sectional area A = 4.5 cm2 and perimeter P = 12 cm, is made of a high-alloy steel [k = 25 W/(m K)]. The temperature of the blade attachement point is 500°C and the blade is exposed to combustion gases at 900°C. The heat transfer coefficient between the blade surface and the combustion gases is 500 W/(m2K). Using the nodal network shown in the accompanying sketch,
(a) determine the temperature distribution in the blade, the rate of heat transfer to the blade and the fin efficiency of the blade and,
(b) compare the fin efficiency calculated numerically with that calculated by the exact method.
GIVEN
Turbine blade exposed to combustion gases
ASSUMPTIONS
The convection coefficient applies at the bladetip
