A heating board has dimensions of 500mm in length, and 1-m-depth. The upper surfaces of the strips
Question:
A heating board has dimensions of 500mm in length, and 1-m-depth. The upper surfaces of the strips are maintained at a uniform surface temperature, Ts = 230oC, by using ten independently controlled, electrical strip heaters, each of which is 50 mm in length. The ambient air at 25oC flows over the strips at a velocity of 60m/s.
a) What is the film temperature of the air?
b) What distance from the leading edge does the critical Reynolds number occur at?
c) Which electric strip experiences flow transition from laminar to turbulence?
d) Referring to the following figure below, which plates do you think would require the maximum electrical power to maintain the surface temperature of 230oC?
Fundamentals of Heat and Mass Transfer
ISBN: 978-0471457282
6th Edition
Authors: Incropera, Dewitt, Bergman, Lavine