mobocracy
Active Member
I'm not an engineer either but wonder if engines draw air from nearer the top of the bige you would be safe thinking the fumes are evacuated with engine draw. My understanding is gasoline fumes, if present, accumulate in the lowest areas of the bilge which could be stagnant absent a bilge blower.
You have to account for convective effects like the air being drawn in being colder and denser than the existing bilge air which is warmer. It's possible to my non-engineer mind that cold vent air may sink and displace warmer low areas of the bilge, as well as the general convective effects of local heating of the air near the engine.
IMHO, it's one of those things that takes PhD math to model and is best done via real world experiments marking the interior air with a colored vapor/smoke type substance and watching it on camera to see which areas clear faster.