How do you mathmatically convert cylinder internal volume into square inches of port?

[bonesninja 5,000+ posts]

I know the formula to find the internal volume of a cylinder....such as a port tube. But how does that translate into square inches of port when trying to figure tuning? example= one round port with 2" ID and its 11 inches long. V=PI*R^2*H So 3.14288*1*11=34.5708cubic inches. What would this equal in square inches of port?

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[req 5,000+ posts]

lawl you serious?

the surface area of a circle is pi * radius squared.

so for a 4" tube, the cross sectional area would be;

3.14 * 2 squared

3.14 * 4

3.14 * 4 = 12.56 square inches

in other words, the "cross sectional area" is only the area of the radius of the circle, not the 3D object, the tube. so draw a circle on a piece of paper (ie: a plane) and find the area of that circle. there is NO depth to a circle. so its just basically "base * height" but a little different since its a circle.

 

[bonesninja 5,000+ posts]

lol i see what you are laughing at....my mistake

 

[req 5,000+ posts]

salight bonesninja man.

just use teh googizzle next time lawl. but i guess mathematicians dont refer to it as "cross sectional area" do they lawl.

 

[bonesninja 5,000+ posts]

its just that my dude is trying to get me to design him a box put he wants round ports but to get the recommended tuning its gonna take like 4@ 4" X 17" ports....i'm just gonna talk him into a nice slot port FTW

 

[req 5,000+ posts]

slots are so much easier to use. round ports gain MINIMAL output (like 1db) because theres less resistance along the circumfrence of the material, but thats simply SPL babble.

slots = daily boxes FTW

they can be spl boxes too, but they are so easy to build its not funnay //content.invisioncic.com/y282845/emoticons/tongue.gif.6130eb82179565f6db8d26d6001dcd24.gif