RatLabGuy
You look like a monkey and smell like one too
- Joined
- May 18, 2005
- Location
- Churchville, MD
An an academic excercise.... Is there any good way or available specs to know the actual inner volume of a tire at rated inflation?
calculating inner tire volume
- Thread starter RatLabGuy
- Start date
I once wrote a program to estimate the area under an an irregularly shaped curve in college. I used the trapezoidal method of estimation but you can only do it if you can plot the shape of the tire on a graph. I'm not sure how much effort you want to put into this but it was a PITA.
A easier idea would be to inflate the tire on a wheel, submerge it, and note the displacement. Then you can submerge the wheel and tire separately. The difference between the two figures would be the actual, not estimated, volume of the inner tire. But that might be too big a pita too.
Aside from that I have nothing. Sorry.
A easier idea would be to inflate the tire on a wheel, submerge it, and note the displacement. Then you can submerge the wheel and tire separately. The difference between the two figures would be the actual, not estimated, volume of the inner tire. But that might be too big a pita too.
Aside from that I have nothing. Sorry.
- Joined
- Mar 17, 2005
- Location
- N. N. Raleigh, NC
discussed w/ wife (BS in math) my idea to rotate a disk about a center point 360 degs seems to be a very complicated math problem 
she suggested using to cylinders inside/outside course that doesn't factor in any pressure but just a pure volume..
you could always fill it with water to a specific pressure and determine how much water you put in ??
making you rig float ?
wife found a web site.. http://www.webcalc.net/calc/0039.php punch in you #s !!
she suggested using to cylinders inside/outside course that doesn't factor in any pressure but just a pure volume.. you could always fill it with water to a specific pressure and determine how much water you put in ??
making you rig float ?
wife found a web site.. http://www.webcalc.net/calc/0039.php punch in you #s !!
RatLabGuy
You look like a monkey and smell like one too
- Joined
- May 18, 2005
- Location
- Churchville, MD
Nah, very simple question actually.
In theory exactly how much air (in oz/lbs) is needed to fill my tires from, say, 10 psi to 33 psi?
Knowing that you can't get it all out anyway, was just wondering (in theory) how big of a CO2 tank is really necessary to cart around. This got me thinking about the problem itself.
The simple way is to think of the tire as a cylinder, volume is easy (area*depth) then subtract out the same for the wheel.
The problem is, who knows what the actual *inside* dimensions are, what with sidewall thickness, oddball rim inset shapes and all. I'm sure you could get within maybe 10% by guesing all this, though. This just mad eme wonder if anybody publishes the actual inside volume per model....
In theory exactly how much air (in oz/lbs) is needed to fill my tires from, say, 10 psi to 33 psi?
Knowing that you can't get it all out anyway, was just wondering (in theory) how big of a CO2 tank is really necessary to cart around. This got me thinking about the problem itself.
The simple way is to think of the tire as a cylinder, volume is easy (area*depth) then subtract out the same for the wheel.
The problem is, who knows what the actual *inside* dimensions are, what with sidewall thickness, oddball rim inset shapes and all. I'm sure you could get within maybe 10% by guesing all this, though. This just mad eme wonder if anybody publishes the actual inside volume per model....
1980CJ7
If it don't go, chrome it
- Joined
- Dec 10, 2006
- Location
- Leesville, NC
Easy with the water displacement method ....I'm sure we all did that in HS physics.....Fill a beaker with 500cc of water and immerse your item to measure.....however much the water level increases is the volume of the item.
do the same with your mounted tire ....THEN subtract the volume of the (unmounted wheel + unmounted tire)
Course the trick is finding a 1,000,000 cc beaker
do the same with your mounted tire ....THEN subtract the volume of the (unmounted wheel + unmounted tire)
Course the trick is finding a 1,000,000 cc beaker