## Fume hood flow model

Domo_Kun - 19-11-2011 at 06:18

I am designing a new fume hood and I would like to run virtual tests to get an idea of the flow before actually building it. I would like to use a finite element modeling software to simulate the flow of air in the hood. I have a CAD model of the hood already, I would just need suggestions of software with good documentation or tutorials to get me started. I'm a mechanical engineer and I have used Ansys to model heat transfer through solids before but I never dealt with fluid finite elements.
Endimion17 - 19-11-2011 at 13:12

Hello, Random.
Would you like to be my friend, too?

Domo_Kun, what level of details are you looking for?

Magpie - 19-11-2011 at 21:05

This document shows some CFD modeling of a fume hood (p.24). Perhaps if you contacted the authors they could steer you to the proper simulation package:

http://ateam.lbl.gov/PUBS/cec/Appendix/doc/EE_FumeHoods.pdf

If you do get some nice graphics please post them on this forum. Good luck.

[Edited on 20-11-2011 by Magpie]

Domo_Kun - 20-11-2011 at 08:34

Thanks for that paper Magpie!

Sure Endimion17, I'll be your friend haha

I'am mostly looking for the ratios of the airflow between the baffles. I have three slots at different heights in my design and I would just like to know if the flow is distributed efficiently or if all of the air will go through one of the slots. Does this make sense?

Magpie - 20-11-2011 at 09:19

Yes, I know what you're saying. I built a 4' fume hood and had to guess at that spacing based on designs shown on the Kewaunee website, IIRC.

 Quote: Originally posted by Magpie I studied the shapes of several hoods on the internet to learn the salient features. Directing flow seemed most important. The baffles do this via 3 gaps. At the bottom is a 2" gap, in the middle a 1" gap, and at the top the baffle is bent inward at a 70 degree angle. There is a 1.5" gap at the top that doesn't show in the picture. This bent end extends out past the 8" duct outlet.

You can see pictures and find other details of my design here: