Answer to Question #286085 in Mechanical Engineering for a.kh

Question

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 ºC

and leaves at a mean temperature of 120 ºC, determine the following

(ignore entrance effects):

[a] The required length of the duct.

[b] The maximum surface temperature.

Answer 1

Answer with diagram and table is given below: