How to make efficient and safe smoke for a wind tunnel

[danjroman]

Hey guys, so for my extended essay in physics i hav came up with a topic that required me to build a wind tunel. I already have that, but then now i need to make smoke or sumthing to pass through the wind tunnel to show the wind patterns and variations. Any ideas in how to create sumthing efficient, safe, and cheap cuz as of now i'm thinking incense is the way to go. Thanks a lot.

[FredGarvin]

Smoke wands are usually simple heaters that vaporize an oil such as mineral oil to make the smoke. The professional units are a bit pricey but work very well of course. You can try to make your own but you may end up with just as much of a science project to get that working right as your tunnel.

Another option to consider would be the smoke bottles that puff out very fine powders. They are usually used for leak detection in HVAC, but they work very well and are cheap. The only thing is that they would not be continuous like a smoke wand.

Do a search under smoke wands and see what you can find. I am sure you'll run the gamut of prices and unit sizes.

Honestly, I think the incense idea wouldn't work to terribly well because the smoke is very low volume and dark. It will be tough to see. However, it is easy and cheap to try, so why not?

[mgb_phys]

I think most commercial systems use engine oil heated with a hot wire in the nozzle.
Wind tunnels generaly don't have a problem with adequate ventilation.

There was a story about an computer maker (IBM/CRAY?) in the 60s using incense to search for airflow in the processor cooling. Picture a small unventilated room, a group of button-down shirt IBM type engineers and a lot of incense!
Management thought they had stumbled on some bizarre drug fuelled cult.

[HallsofIvy]

Another method (less polluting to your environment!) is to drip water onto dry ice producing a white "smoke".

[montoyas7940]

Perhaps something like scale model train smoke would work.

[Jupiter6]

I believe the tunnel in our lab burned kerosene (extremely rich ratio)

[Phrak]

beekeepers have come up with a simple, adaptable device if you're imagining a roll-your-own wind tunnel. The bee's even find it enviromentally acceptable (good grief @ environmental paranoia).