Fuel System


The fuel system in the SQ-2000 is typical of most canard airplanes... I think.  This is the only aircraft I've built, so I don't really know.  Here's the basics: The strakes form the left and right main fuel tanks, each holding about 20 gallons.  They are plumbed to gravity feed into a center fuel sump, located at the aft-rear of the aircraft--just forward of the firewall, on top of the NACA inlet.  Fuel will then be pumped from the bottom of the center sump directly to the engine.

Center fuel sump construction
The center fuel sump is essentially just a box with a couple of baffles.  The first step was to layup a bunch of flat panels (.25" fuel resistant foam core).
Once the panels were all cured and trimmed up, I temporarily taped them together, minus the front panel, to get an idea of what I was creating.
Then I slid it into place to make sure there were no installation problems.  

At this point, it became clear to me that this design was wasting valuable fuel volume.  Since the sump fits on top of the NACA inlet, it's angled down at 12 degrees.  I figured if I redesigned the side panels so that the top of the sump was waterline-level, I could gain an extra gallon of fuel with virtually no loss of cabin space, and only a few more ounces of glass and core.

Here's the redesigned version with angled side panels.  When installed, the top panel will the level.

Before closing out the box, I need to coat it with a fuel tank sealer, but I haven't decided what type of fitting to use for the exit port (angle vs. tee), so I'm holding off for now.


 

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