Nice to know someone has actually experimented with these things. Theory and practice don't always coincide. Any idea why the funnel matters when it doesn't change the surface area? Does CO2 tend to rise towards the top of an aquarium (this is something I hadn't considered)? Is it simply causing more water movement in the tubing? I believe you, I'm just trying to figure out the principle involved.
I probably should have simply said water circulation as opposed to Reynold's number since we are dealing with very low flow rates where turbulence is minimal and viscosity doesn't matter (I was simply looking for a term that indicated how much movement was occurring at the gas/liquid interface). My fluid mechanics class was 19 or 20 years ago. If CO2 dissipates that quickly then water circulation probably doesn't matter much at all.
Last edited by smannell; 04-08-2011 at 08:32 PM.
Reason: swapped turbulence & viscosity by accident