# hw1-heat - ME 324 HW #1 21.02.2011 1. A square isothermal...

This preview shows page 1. Sign up to view the full content.

ME 324 HW #1 21.02.2011 1. A square isothermal chip is of width w = 5 mm on a side and is mounted in a substrate such that its side and back surfaces are well insulated, while the front surface is exposed to the flow of a coolant at T = 20 ºC. From the reliability consideration, the chip temperature must not exceed T = 85ºC. (1) If the coolant is air and the corresponding convection coefficient is h = 200 W/m 2 K, what is the maximum allowable chip power? (2) If the coolant is a dielectric liquid for which h = 3000 W/m 2 K, what is the maximum allowable power? w = 5 mm Coolant chip 2. A sphere 4.0 cm in diameter is heated to a temperature of 150ºC and is enclosed in a large room at 20ºC. Air in the room is also at 20ºC. The average convection heat transfer coefficient is 9.8 W/m 2 K. The surface emissivity of the sphere is 0.65. Calculate the total heat loss due to both convection and radiation. 3.
This is the end of the preview. Sign up to access the rest of the document.

## This note was uploaded on 10/05/2011 for the course ME me352 taught by Professor Koraykadirsafak during the Spring '11 term at Yeditepe Üniversitesi.

Ask a homework question - tutors are online