Let’s assume that the package in Problems 4.12 and 4.13 is located in a laminar airflow with velocity of 3 m/s and temperature of 40°C and simultaneously radiates to the enclosure, which is at 35°C....

Let’s assume that the package in Problems 4.12 and 4.13 is located in a laminar airflow with velocity of 3 m/s and temperature of 40°C and simultaneously radiates to the enclosure, which is at 35°C. What is the average surface temperature of this package and contributions of forced convection and radiation heat transfer rates?

Multiple modes of heat transfer can happen simultaneously. Let’s assume that the package in Problems 4.12 and 4.13 is mounted vertically and dissipates its heat by laminar natural convection as well as radiation heat transfer. Find out its average surface temperature and contributions of natural convection and radiation heat transfer rates.

Problem 4.13

The emissivity of the package in Problem 4.12 is 0.8 and it is surrounded by an electronic enclosure with temperature 35°C. If the only mode of heat transfer from this package is radiation heat transfer, what is its average surface temperature?

Problem 4.12

Consider a 40 mm × 40 mm electronic package that dissipates 5 W. Calculate the average top surface temperature of the package if all the heat is dissipated from the top of the package, the air temperature around the device is 40°C, and

a. the air flows with a velocity of 3 m/s over the package and flow is laminar, b. the package is mounted vertically and natural convection is laminar, c. the package is mounted horizontally in air and the top of the package is facing up