A circular metal disk having a diameter of 0.4 m isplaced
Chapter 12, Problem 12.124(choose chapter or problem)
A circular metal disk having a diameter of 0.4 m isplaced firmly against the ground in a barren horizon-tal region where the earth is at a temperature of280 K. The effective sky temperature is also 280 K.The disk is exposed to quiescent ambient air at 300 Kand direct solar irradiation of 745 W/m2. The surfaceof the disk is diffuse with ???0.9 for 0???1?mand ???0.2 for ??1?m. After some time haselapsed, the disk achieves a uniform, steady-statetemperature. The thermal conductivity of the soil is0.52 W/m?K.(a) Determine the fraction of the incident solar irra-diation that is absorbed.(b) What is the emissivity of the disk surface?(c) For a steady-state disk temperature of 340 K,employ a suitable correlation to determine theaverage free convection heat transfer coefficientat the upper surface of the disk.(d) Show that a disk temperature of 340 K doesindeed yield a steady-state condition for the disk.
Unfortunately, we don't have that question answered yet. But you can get it answered in just 5 hours by Logging in or Becoming a subscriber.
Becoming a subscriber
Or look for another answer