Forced air at T= 25ºC and V= 12 m/s is used to cool electronic elements on a circuit board. One such element is a chip, 4 mm ×4

Question

3 years ago

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Forced air at T= 25ºC and V= 12 m/s is used to cool electronic elements on a circuit board. One such element is a chip, 4 mm ×4

mm, located 120 mm from the leading edge of the board. Experiments have revealed that flow over the board is disturbed by the elements and that convection heat transfer is correlated by an expression of the form Nµx= 0.04 Rex^0.85. Pr^1/3. Required:Estimate the surface temperature of the chip if it is dissipating 30 mW.

Engineering

1 answer:

tia_tia [17] · Answer 1 · 2022-05-04T06:33:13+03:00

Answer:

The surface temperature of the chip 39.99°C

Explanation:

Assumptions

1. Steady state condition.

2. Power dissipated within the chip is lost by convection across upper surface only.

3. Chip surface is isothermal

4. The average heat transfer coefficient for the chip surface is equivalent to the local value x - L

Properties: from table. See attachment (4)

See attachment for complete solution to the problem

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