Fuel is a liquid. What did you learn in school about liquids?
Comment on how/where did the concord hold 42 of these tanks ?
0xKesh@lemmy.dbzer0.com 2 days ago
Taking an absolute guess here…
But could it be the difference between raw capacity (as shown in the tank image) vs compressed?
My thinking here is from when F1 teams started chilling down the fuel to fit more in a tank.
Treczoks@lemmy.world 2 days ago
Successful_Try543@feddit.org 2 days ago
Now all in choir: liquids are incompressible!
Things aside, from an engineering perspective, liquids have a much larger resistance (bulk modulus) against compression than against shear. Thus, water is considered incompressible whereas steel isn’t, despite the bulk modulus of water is about 2 GPa and the one of steel is 160 GPa.
They were talking about the F1 teams chilling the fuel to fit some extra fuel inside the tank. As the thermal expansion of coefficient of fuel is about 1·10^-3 /K, they can fit another 1 % of fuel into the tank for every 10 K of extra chilling. However, this likely has its limits at low single digit percentage values, which is sufficient for some extra miles in F1 but not useful for dimensioning fuel tanks of the aircraft around that.
Treczoks@lemmy.world 2 days ago
I’m fully with you here. The one or two percent thermal expansion/compression is way below the usual safety margin of a plane, anyway.
Wfh@lemmy.zip 2 days ago
The gains from increased density were extremely marginal, but then again F1 is a marginal gains game. Maybe you could push a couple extra % more in some parts of the race to gain or secure track position but it wouldn’t change overall performance. That’s also why the FIA switched to fuel weight instead of volume.
On a plane like this it wouldn’t make a difference as weight is more important than volume.
0xKesh@lemmy.dbzer0.com 2 days ago
The FIA also added a temperature limit to reduce this effect that I was mentioning. I just did some slight research on it, looks like when it was at its most effective in the 80’s, cars had a 195 litre tank, with fuel chilled to about -30c this allowed for an extra 10-12 litres, or about 6% increase.
This change was huge in that era of racing, basically meant that drivers could stay at 100% pace for longer without nursing fuel. Coincidentally, when doing some reading on this I also found that apparently chilled fuel during the refuelling era of F1 also helped increase the flow.
Anyway, that was my thinking originally lol, looks to be actually answered in the comments now though. Thanks for the reply!