Topic: Heat Transfer
The critical radius of insulation for a spherical shell is
- A. thermal conductivity of insulating material / heat transfer coefficient at the outer surface
- B. 2 x thermal conductivity of insulating material / heat transfer coefficient at the outer surface
- C. thermal conductivity of insulating material / 2 x heat transfer coefficient at the outer surface
- D. heat transfer coefficient at the outer surface / thermal conductivity of insulating material
Answer: B. 2 x thermal conductivity of insulating material / heat transfer coefficient at the outer surface
Explanation: Critical radius of insulation rc = 2K/h for a spherical shell, whereas rc = K/h for a cylindrical shell.