Phunny Physics II (paper airplanes in space)

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dr wogz

dr wogz

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OK, hypothetically speaking, and a proposal:

You're on the ISS; in space, in a 0-G environment. Better yet, you're one of the new Mars colonists en route to Mars (No major gravitational influences). Again, a 0-G environment. And it just so happens that NASA engineers gave the ship / station a massive gymnasium. A typical high school gym. A massive volume pressurised with a typical earth atmosphere. But no gravity.

You & the other space voyagers are board one day, and you decide to hold a paper airplane contest in said large room. Many different designs are created, and all are eager to fly the farthest, longest duration, etc...

Everyone is lined up against one wall, and the planes are launched (tossed?).. What are their flight paths? Do some designs perform differently than others?
(Standard 'letter' folded paper planes (or A4 for the European travellers) )
 
One with its center of pressure behind its center of mass and radial symmetry would work best, I think.
Sort of a paper rocket...
 
Infinite acceleration ultimately resulting in the untimely deaths of all involved.

You monster.
 
Their flight paths would be very short. Since thrust is what overcomes drag, gliders would be kinda boring in weightlessness, gravity being the thrust in a glider's case.
 
I'm far from gifted in Physics, but seems to me that what's lacking isn't momentum, since that's imparted by the "tosser", but without gravity, the only force acting to stop the plane would be drag. Therefore, the plane would fly straight (non-parabolic drop), but gradually slow down, to eventually just hang...
 
soopirV said:
I'm far from gifted in Physics, but seems to me that what's lacking isn't momentum, since that's imparted by the "tosser", but without gravity, the only force acting to stop the plane would be drag. Therefore, the plane would fly straight (non-parabolic drop), but gradually slow down, to eventually just hang...
Click to expand...

Exactly, and drag would take a long time to completely stop the plane.


Steve Shannon
 
Distance is reliant on drag, so all you need is a good CP/CG relationship and otherwise get the thing as dense as possible, with an approximately 6:1 length to width ratio. Small fins just enough to get it stable. Smooth outside. Parabolic nose and conical boat tail. Strong thrower.
 
Unless it was a perfect throw, the plane would get lift one way or the other. Depending on how well it stabilized itself, it would either then go straight until it hit a wall (positive stability) or spiral out of control (negative stability). Going straight it would slow down marginally from air drag, but spiraling out of control might come to a stop or near stop because of all of the drag from looping around. Given constant throw speed, a highly unstable design may have the longest hang time before hitting a surface.
 
boatgeek said:
Unless it was a perfect throw, the plane would get lift one way or the other. Depending on how well it stabilized itself, it would either then go straight until it hit a wall (positive stability) or spiral out of control (negative stability). Going straight it would slow down marginally from air drag, but spiraling out of control might come to a stop or near stop because of all of the drag from looping around. Given constant throw speed, a highly unstable design may have the longest hang time before hitting a surface.
Click to expand...

For the longest duration: Just crumple the paper into a ball and give it a slight nudge.
 
Incongruent said:
Distance is reliant on drag, so all you need is a good CP/CG relationship and otherwise get the thing as dense as possible, with an approximately 6:1 length to width ratio. Small fins just enough to get it stable. Smooth outside. Parabolic nose and conical boat tail. Strong thrower.
Click to expand...

Can't have a CG in no gravity! Fun to think about.
 
watheyak said:
Can't have a CG in no gravity! Fun to think about.
Click to expand...

It's technically the Center of Mass, so unless it has no mass it WILL have a "CG".

Since you're doing this in the ISS and there is some kind of gaseous atmosphere, there will be drag impeding its forward motion. This also means that the CP is going to matter too... it needs to be behind the CG. Although there may not be gravity, the drag will most likely cause it to veer from a perfectly strait path unless it's absolutely symmetrical. Eventually it will hit something... hopefully nothing important.
 
My guess would be that rolling the paper into a sharp cone and tossing it like a dart would work best (at least for distance - probably also for duration if the room is large enough). A more traditional paper airplane design would have a wing that might generate lift. In the zero-G environment, that would cause it to turn or loop.

I won a paper airplane contest during a scouting event once. The goal was to create the plane and have it be the first one to cross a line a few yards away. I made a simple "paper dart" that was quick to assemble and "flew" straight. It was more a lucky case of me not knowing how to fold a proper paper airplane, but, in retrospect, it makes sense.

-- Roger
 
^^ This.

Wings generate lift to counter gravity. Paper airplanes do this as well. It would loop until drag brought to a low enough speed then it would tumble eventually coming to a standstill.
 
BuiltFromTrash said:
^^ This.

Wings generate lift to counter gravity. Paper airplanes do this as well. It would loop until drag brought to a low enough speed then it would tumble eventually coming to a standstill.
Click to expand...

is this implying that the folded wings on the paper airplane have a traditional airfoil? (flat bottom with the curvy part on top, not a symmetrical airfoil, or just a flat 'vane / fin')
 
Zeus-cat said:
Agreed. I think that this would be the best design.
Click to expand...

Too draggy. The OP specified that the competition would be held inside "a massive volume pressurized with a typical earth atmosphere." So, drag is a consideration.

-- Roger
 
dr wogz said:
is this implying that the folded wings on the paper airplane have a traditional airfoil? (flat bottom with the curvy part on top, not a symmetrical airfoil, or just a flat 'vane / fin')
Click to expand...

That airfoil thing is a myth! Everything you've been taught about how an airplane flies is wrong! I can prove it with one, simple statement:

Airplanes can fly upside down.​

While the typical airfoil shape of the wing provides lift, it isn't the complete explanation. (Otherwise, airplanes would not be able to fly upside-down.)

Lift is also generated by the angle-of-attack. A flat wing, such as used in toy balsa gliders (as well as many boost-gliders) can provide lift. In the same way, a paper airplane can have a flat wing that provides lift.

-- Roger
 
OK, let's go back to the OP's goals:

Distance: As long as it flies straight, the maximum distance available is the maximum size of the room. To win this, you need a plane that flies straight, and nothing else. Cones, darts, etc. are all good choices. After the first set of throws (you're on a Mars ship, so you'll have LOTS of time to repeat the contest!), people will probably figure out that this leads to a 20-way tie for first place. At that point, they probably change the goal to average speed to the far wall (distance divided by time).

Average speed: Low drag and straight flight are the keys for this. Jadebox's dart is the solution, with a hard throw.

Duration: Assuming that duration ends when the plane hits a surface, you want a high drag option. I still think my looper would be good, but Incongruent's crumpled up ball would work well also. After the first throw, they'll discover that they need to assign a throw speed so you can't just tap the ball/plane and have it drift slowly to the other side. What I like about a plane that constantly loops is that it may never reach a wall, no matter how hard you throw it at first.

Those are the OP's goals, plus bonus average speed. Feel free to add your own with what designs you think would win.
 
boatgeek said:
OK, let's go back to the OP's goals:

Distance: As long as it flies straight, the maximum distance available is the maximum size of the room. To win this, you need a plane that flies straight, and nothing else. Cones, darts, etc. are all good choices. After the first set of throws (you're on a Mars ship, so you'll have LOTS of time to repeat the contest!), people will probably figure out that this leads to a 20-way tie for first place. At that point, they probably change the goal to average speed to the far wall (distance divided by time).

Average speed: Low drag and straight flight are the keys for this. Jadebox's dart is the solution, with a hard throw.

Duration: Assuming that duration ends when the plane hits a surface, you want a high drag option. I still think my looper would be good, but Incongruent's crumpled up ball would work well also. After the first throw, they'll discover that they need to assign a throw speed so you can't just tap the ball/plane and have it drift slowly to the other side. What I like about a plane that constantly loops is that it may never reach a wall, no matter how hard you throw it at first.

Those are the OP's goals, plus bonus average speed. Feel free to add your own with what designs you think would win.
Click to expand...

I don't think you would want high drag. I think you want low velocity and low drag. An aluminum wire with a point at the forward end made of a highly dense material such as tungsten would work great.
 
Steve Shannon said:
I don't think you would want high drag. I think you want low velocity and low drag. An aluminum wire with a point at the forward end made of a highly dense material such as tungsten would work great.
Click to expand...

If you can start with low velocity, Incongruent's crumpled up ball will hit the wall after your wire.
 
The requirement for materials is to fold the plane from a single sheet of standard sized paper. (A4)
 
jadebox said:
That airfoil thing is a myth! Everything you've been taught about how an airplane flies is wrong! I can prove it with one, simple statement:

Airplanes can fly upside down.​

While the typical airfoil shape of the wing provides lift, it isn't the complete explanation. (Otherwise, airplanes would not be able to fly upside-down.)

Lift is also generated by the angle-of-attack. A flat wing, such as used in toy balsa gliders (as well as many boost-gliders) can provide lift. In the same way, a paper airplane can have a flat wing that provides lift.

-- Roger
Click to expand...

That doesn't disprove anything with regards to the airfoil shape. I assume you are being sarcastic.
 
jadebox said:
Too draggy. The OP specified that the competition would be held inside "a massive volume pressurized with a typical earth atmosphere." So, drag is a consideration.

-- Roger
Click to expand...

I agree, but with a caveat. The crumpled up ball will be the easiest thing to throw in a straight line. All of the sleek designs will be difficult to control and will be prone to drifting off the straight line intended by the thrower. Remember, there is almost no gravity so any defect in a wing or nose will cause the plane to go up, down, left, right, rotate on the primary axis, etc. You don't have gravity helping keep the plane traveling in a straight line by keeping the wings level.

If you watched the video with Adam and Jamie and the guy on the ISS you will notice that the "dart" he used had a large mass for the nose. Even that was difficult to throw straight. Very low mass sheets of paper will be much more prone to any unwanted deflections. The wadded up ball will also have unwanted forces, but since the CP and CG (or CM) or essentially the same it should travel in a straighter line than the planes.
 

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