Question

An array of 10 silicon chips, each of length L = 10 mm on a side, is insulated on one surface and cooled on the opposite surface by atmospheric air in parallel flow with Tꚙ = 24C and uꚙ = 40 m/s. When in use, the same electrical power is

Answer 1

a) 0.3 W

b) 0.81 W

c) It is better to orient array normal to the air flow

Step-by-step explanation:

Here is the complete question from my textbook.

An array of 10 silicon chips, each of length L = 10 mm on a side, is insulated on one surface and cooled on the opposite surface by atmospheric air in parallel flow with T∞ = 24°C, u∞=40m/s. When in use, the same electrical power is dissipated in each chip, maintaining a uniform heat flux over the entire cooled surface. If the temperature of each chip may not exceed 80°C,

a) what is the maximum allowable power per chip?

b) What is the maximum allowable power if a turbulence promoter is used to trip the boundary layer at the leading edge?

c) Would it be preferable to orient the array normal, instead of parallel, to the airflow?

See attachment for calculation.