A turbine blade with a characteristic length of 1 m is cooled in an atmospheric pressure wind tunnel by air

Question:

A turbine blade with a characteristic length of 1 m is cooled in an atmospheric pressure wind tunnel by air at 40?C and a velocity of 100 m/s. At a surface temperature of 500 K, the cooling rate is found to be 10,000 watts. Apply these results to estimate the cooling rate from another turbine blade of similar shape, but with a characteristic length of 0.5 m operating with a surface temperature of 600 K in air at 40?C and a velocity of 200 m/s.GIVENA turbine blade in a wind tunnelLength of blade (L1) = 1 mAir temperature (Tai) = 40?C = 313 KAir velocity (U??1) = 100 m/sAir pressure = 1 atmBlade surface temperature (Ts) = 500 KCooling rate (q) = 10,000 WASSUMPTIONSSteady state for both casesUniform blade surface temperatureAir temperature is constant and the same in both cases

image

From Appendix 2, Table 27, for dry air at the film temperatures Case 1 Case 2T = 406.5 K T = 456.5 KKinematic viscosity, v × 106 (m2/s) 27.6 33.2Thermal conductivity, k (W/(mK)) 0.0328 0.0360

This problem has been solved!


Do you need an answer to a question different from the above? Ask your question!

Step by Step Answer:

Related Book For  answer-question

Principles of heat transfer

ISBN: 978-0495667704

7th Edition

Authors: Frank Kreith, Raj M. Manglik, Mark S. Bohn

View Solution
Create a free account to access the answer
Cannot find your solution?
Post a FREE question now and get an answer within minutes. * Average response time.
Question Posted: November 26, 2011 11:23:02