• Support PF! Buy your school textbooks, materials and every day products Here!

Rectangular Fin Heat Transfer

  • Thread starter kdb12
  • Start date
  • #1
1
0

Homework Statement


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)

Homework Equations



ηo = 1 - (NAc/At) (1-ηf)
At = NAc+Ab

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.)
 

Answers and Replies

  • #2
20,262
4,273
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
 
  • #3
260
9
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.
 
Last edited:

Related Threads on Rectangular Fin Heat Transfer

  • Last Post
Replies
1
Views
4K
Replies
1
Views
2K
Replies
1
Views
2K
Replies
0
Views
1K
Replies
0
Views
3K
  • Last Post
Replies
2
Views
2K
Replies
4
Views
4K
  • Last Post
Replies
1
Views
673
  • Last Post
Replies
5
Views
2K
  • Last Post
Replies
0
Views
1K
Top