Скачать или смотреть Determine Thermal Boundary Layer - Enclosed VS Non-Enclosed Space Convection - W11Q4

Two vertical flat plates are located within a tank of water at 25℃. They are sufficiently far from each other to consider the system as a non-enclosed one. Each plate is 30 cm in height and both plates are held at 65 ℃. You may assume the boundary layer thickness d, is given by the equation in below. There is no initial flowing water.

d/L=3.93Pr^−1/2*(0.952+Pr)^1/4Gr^−1/4


a) Determine the Grashof number for one plate.
b) Determine the minimum spacing that would be needed between the two plates, so that the boundary layers do not interact.
c) How would you analyze the problem differently if you knew the boundary layers were interacting?

Answer: a) 1.23 * 10^10 b) Minimum 5.6mm c) Problem becomes an enclosed vertical plate natural convection system