ORIGINAL: Campgems
CGr, I have shyed away from this type clunk, thinking that as the fuel got low, it would start mixing air with the fuel as part of the filter would be above fuel level. Do you run into any issues with low fuel with this. I always though it would be better to have the single small inlet that would either pick up fuel or air, kind of a binary delivery. Maybe I'm borrowing trouble and missing out on a good idea???
Don
After many, many years of building tanks and competing in an event where the flight time was VERY important and there was no throttle, and trying lots and lots of designs..................................
The type CGRetired suggests is excellent. It's got a huge filtering area and does seem to insure no bubbles from foaming fuel for one. What you've suggested, having just a single small inlet is a good idea too. But what you are worried about actually doesn't seem to happen.
What happens with any inlet is that the very instant it is uncovered it will suck air. Size doesn't matter. As soon as the fuel level uncovers the inlet, you're out of gas. The tank won't ever be, but the engine will be. A small inlet will be able to pull a higher percentage of the fuel out before it sees air. A larger inlet will leave more fuel in the tank. In theory, the big inlet should be more apt to cause a stumble just at empty. In practice, it usually doesn't. And when it does, it's just a stumble, not a lean run. And that is actually a good deal, not a bad one.
The filter CGR advises is a good idea for sure.