Consider a 15-cm * 20-cm printed circuit board (PCB) that has electronic components on one side. The board is placed in a room at 20°C. The heat loss from the back surface of the board is negligible. If the circuit board is dissipating 8 W of power in steady operation, determine the average temperature of the hot surface of the board, assuming the board is (a) vertical, (b) horizontal with hot surface facing up, and (c) horizontal with hot surface facing down. Take the emissivity of the surface of the board to be 0.8 and assume the surrounding surfaces to be at the same temperature as the air in the room. Evaluate air properties at a film temperature of 32.5°C and 1 atm pressure. Is this a good assumption?
Consider a 15-cm * 20-cm printed circuit board
(PCB) that has electronic components on one side. The board
is placed in a room at 20°C. The heat loss from the back
surface of the board is negligible. If the circuit board is dissipating
8 W of power in steady operation, determine the average
temperature of the hot surface of the board, assuming the
board is (a) vertical, (b) horizontal with hot surface facing
up, and (c) horizontal with hot surface facing down. Take the
emissivity of the surface of the board to be 0.8 and assume
the surrounding surfaces to be at the same temperature as
the air in the room. Evaluate air properties at a film temperature
of 32.5°C and 1 atm pressure. Is this a good assumption?
Trending now
This is a popular solution!
Step by step
Solved in 10 steps with 27 images
