Air is heated in a 4cm×4cm sheet metal duct with a uniform surface heat flux of 590 W/m2. The mean velocity is 3.2 m/s. The sheet metal has an average roughness 0.05 mm. If the air enters at 20 °C and leaves at a mean temperature of 120 °C, determine the following (ignore entrance effects): [a] The required length of the duct. [b] The maximum surface temperature.

Air is heated in a 4cm×4cm sheet metal duct with a uniform surface heat flux of 590 W/m2. The mean velocity is 3.2 m/s. The sheet metal has an average roughness 0.05 mm. If the air enters at 20 °C and leaves at a mean temperature of 120 °C, determine the following (ignore entrance effects): [a] The required length of the duct. [b] The maximum surface temperature.

Principles of Heat Transfer (Activate Learning with these NEW titles from Engineering!)

8th Edition

ISBN:9781305387102

Author:Kreith, Frank; Manglik, Raj M.

Publisher:Kreith, Frank; Manglik, Raj M.

Chapter7: Forced Convection Inside Tubes And Ducts

Section: Chapter Questions

Problem 7.20P

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