Fall2008_Midterm

# Fall2008_Midterm - Midterm Progress Assessment ECH 3223,...

This preview shows pages 1–2. Sign up to view the full content.

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Midterm Progress Assessment ECH 3223, Fall 2008 Monday, October 20 Directions: • Two hours. • Open book. • No notes. • Calculator needed. • Start each problem on a new page. • Maximize your score by showing all work. • Good luck to you!! Problem #1: Quick questions (15 points) a) The thermal diffusivity α = k/ρc p has what units? b) By performing a change of variable, determine c in each case: ∂φ ∂x = c ∂φ ∂z 1) z = x/L 2) z = 1 / √ x 3) z = x 2 c) If the effectiveness of a cylindrical pin fin of length L and radius R is 2, what is the efficiency of the fin? Problem #2: Non-uniform generation (20 points) The exposed surface ( x = 0) of a plane wall of thermal conductivity k is subjected to microwave radiation that causes volumetric heating to vary as ˙ q ( x ) = ˙ q 1- x L , where ˙ q (W/m 3 ) is a constant. The boundary at x = L is perfectly insulated, while the exposed surface is maintained at a constant temperature T . If the temperature far from the wall is...
View Full Document

## This note was uploaded on 01/08/2010 for the course ECH 3223 taught by Professor Asthigiri during the Spring '08 term at University of Florida.

### Page1 / 3

Fall2008_Midterm - Midterm Progress Assessment ECH 3223,...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online