{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

hw3 2011

# hw3 2011 - C HEMICAL E NGINEERING 1 20B H omework 3 d ue M...

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

CHEMICAL ENGINEERING 120B Homework 3 due Monday, January 31, 2010 1. An alloy metal fin (k = 64 Btu/h/ft:;OF) is used on a wall with heat transfer coefficient h 50Btu/h.ft 2 °F. The fin has a rectangular cross section, a base 0.05 inch thick, a length of 1 inch, and a width 4 inches. a. What is the thermal decay length>. in the fin? Is it short or long compared with the length of the fin? Based on this, do you expect the fin efficiency to be high or low? a. Find t he fin efficiency. c. What is the rate of heat loss from a single fin if the wall is at 200 F and the air is at 80F? 2. Derive a differential equation for the steady temperature distribution in a circumferential fin of constant base thickness 2b, inner radius RJ and outer radius R2 (length L = R2 - Rd, sticking out of a cylinder of radius R 1 . Just as in class, assume no heat transfer out the end, that convection follows Newton's law (heat transfer coefficient It), and conduction follows Fourier's law (thermal conductivity k). What are boundary conditions? Non-dimensionalize -

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.

{[ snackBarMessage ]}

### What students are saying

• As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

Kiran Temple University Fox School of Business ‘17, Course Hero Intern

• I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

Dana University of Pennsylvania ‘17, Course Hero Intern

• The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

Jill Tulane University ‘16, Course Hero Intern