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Fuel fraction?I'm curious if anybody has compiled data regarding fuel-fraction data on aircraft in WWII? I know there are a number of variables that affect an aircraft's range and performance
Fuel fraction?
Hi,Weight of fuel carried vs. total weight of aircraft before take off.
Agreed. I'm compiling data on the F4U & F6F series, I'm curious if you got anything on the early P-51B's (they lacked the 85 gallon center tank), the later P-51B/C/D's and the P-51H.After doing a little more digging I did find a spreadsheet where I had the data for some Hawk 75 (P-36) variants and some Brewster Buffalo variants. They all appear to be around 10-13%.
Actually, from what it would appear, bombers usually had a higher fuel-fraction. That said, it kind of makes sense because volume favors large objects.With bombers there is a fuel load and cruising speed that gives a range where no bombs can be carried.
You mean the Halifax had a lower L/D or it's presence in the stream actually affected the Lancs?With the Halifax and Lancaster on long range missions at the same cruising speed, being in the same bomber stream the extra drag of the Halifax meant it carried a much lighter bomb load and so was much less effective.
To cruise at the same speed the Halifax needed more fuel so carried less bombs. Planes aren't designed around this ratio it is what results, bombers had to carry a load and defensive armament a long way, so had more fuel.Actually, from what it would appear, bombers usually had a higher fuel-fraction. That said, it kind of makes sense because volume favors large objects.
You mean the Halifax had a higher L/D or it's presence in the stream actually affected the Lancs?
To cruise at the same speed the Halifax needed more fuel so carried less bombs. Planes aren't designed around this ratio it is what results, bombers had to carry a load and defensive armament a long way, so had more fuel.
Didn't you mean a lower L/D? A higher L/D implies higher performance. A plane with a drag problem is stuck with a lower L/D.You mean the Halifax had a higher L/D or it's presence in the stream actually affected the Lancs?
Oh, okayTo cruise at the same speed the Halifax needed more fuel so carried less bombs.
I assume that, for a long-ranged fighter, there would be the natural presumption that you'd want as much internal fuel, while having enough structural strength to pull the target g-load, even if they didn't think of a specific percentage.Planes aren't designed around this ratio it is what results, bombers had to carry a load and defensive armament a long way, so had more fuel.
Good source, I was actually planning on using that exact one. I didn't know the F6F-3 and F6F-5 were almost the same in weight (usually, designs have a tendency to creep up as time goes on). That said, I do remember the USN wanting to increase the oil-capacity (to 19 gallons evidently), the RAF also had started increasing oil capacity on fighters as well. I figured it had to do with longer-ranged flying.
The P-51D had longer range right? As for the drop-tanks the P-51B/C/D carried, what sizes were typical when they started using them for escorts?The fuel fraction for P-51D with 269 gal internal fuel at full internal combat load out Gross Weight of 10200 pounds = 1614/10200 = 15.8%, the P-51B was slightly higher at 1614/9600 = 16.8%.
Yeah, I mistyped. I corrected it.Didn't you mean a lower L/D?
For same internal fuel the P-51B had slightly longer range - with and without tanks, due to less induced drag at cruise speeds (all speeds).Oh
The P-51D had longer range right? As for the drop-tanks the P-51B/C/D carried, what sizes were typical when they started using them for escorts?
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Things progressed as horsepower increased. To design a long range fighter in the early to mid 1930s you needed 2 engines. Things also progressed much more quickly when it was obvious war was coming and when it was actually declared. Range is one issue, the plane has to be competitive with the opposition when it gets to where it is going though.Oh, okay
I assume that, for a long-ranged fighter, there would be the natural presumption that you'd want as much internal fuel, while having enough structural strength to pull the target g-load, even if they didn't think of a specific percentage.
That's interesting, I thought the P-51D was cleaner.For same internal fuel the P-51B had slightly longer range - with and without tanks, due to less induced drag at cruise speeds (all speeds).
the 110 and 165's were how they were able to escort the B-29?75 gallon externals until May 1944, 110 and 165gal (Pacific only).
Plus, a lot of proponents of long-range fighters had some bizarre ideas of what they wanted in an escort.Things progressed as horsepower increased. To design a long range fighter in the early to mid 1930s you needed 2 engines. Things also progressed much more quickly when it was obvious war was coming and when it was actually declared. Range is one issue, the plane has to be competitive with the opposition when it gets to where it is going though.
Who proposed an escort and when?Plus, a lot of proponents of long-range fighters had some bizarre ideas of what they wanted in an escort.
If we rid these specifications from things, it would have been way easier to achieve. The point, was simply a fighter that could do all the stuff a fighter could, and fly very far, and that probably would require two engines if we didn't want to go the way of the A6M.
- Multi-crew
- At least two, which included a gunner: The idea was a gunship that could rove over the bomber formation and add to the defensive firepower
- There also seemed a strong predilection among some for multi-role aircraft (such as the Zerstorers) that were both fighters and bombers
- Internal Fuel: This was the US only, we were adamantly opposed to external fuel tanks for some time, so the range had to be totally internally.