Register to reply

Rectangular Fin Heat Transfer

by kdb12
Tags: heat, rectangular, transfer
Share this thread:
kdb12
#1
Mar20-13, 12:42 PM
P: 1
1. The problem statement, all variables and given/known data
A straight, rectangular fin made from 2024 aluminium has a thickness of t = 3mm and length L = 20mm. Base temperature is 100 C and it is exposed to a fluid at 20 C.
h = 60 W/m^2-K
k = 185 W/m-K

(a) Determine the heat transfer rate from the fin to the fluid per unit length
(b) Repeat (a) if the fin is made of copper (h = 400 W/m^2-K)

2. Relevant equations

ηo = 1 - (NAc/At) (1-ηf)
At = NAc+Ab

3. The attempt at a solution

nf = tanh(mLc)/mLc

(I know this equation is right, but I'm lost from this point forward. Any help would be excellent.)
Phys.Org News Partner Science news on Phys.org
'Smart material' chin strap harvests energy from chewing
King Richard III died painfully on battlefield
Capturing ancient Maya sites from both a rat's and a 'bat's eye view'
Chestermiller
#2
Mar20-13, 05:50 PM
Mentor
Chestermiller's Avatar
P: 5,387
Do you know how to write the steady state differential heat balance equation for a cooling fin, including the conductive heat transfer along the fin and the convective heat transfer from the fin to the surrounding air? If so, lets see it.

Chet
caldweab
#3
Mar20-13, 06:15 PM
P: 263
There's formulas for this...it's really plug and chug, you're given everything you need.

You need to calculate your m and M

for a rectangular fin m=(2h/kt)^1/2; plug in your h, k and thickness

For a rectangular fin M= (2hw^2tk)^1/2 *(tb-tinfinity) again substitute your h,k, width and thickness.

Now that you have M and m you can just apply the formula, you have everything you need.


Register to reply

Related Discussions
Heat Transfer: Calculating heat transfer rate? Engineering, Comp Sci, & Technology Homework 4
How long to melt the ice(heat, heat transfer, latent heat) Introductory Physics Homework 3
Equation for heat transfer and output of heat from a thermal storage unit Classical Physics 0
How to transfer heat dissipate by heat sink into one spot Mechanical Engineering 3
Is the overall heat transfer coefficient constant for a certain heat exchanger? Advanced Physics Homework 0