rocket help
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To find the area of the diameter of the bodytube- 3.14(Pi) x the radius squared. I used this calculation on my recent scratch build. A cross section of the body tube is 3 inch so the radius is 1/2 of the diameter:
3.14(Pi) x 1.5 x 1.5 = 7.065
7.065 is the area of a cross section of a 3 inch body tube.
Clear as mud? There are lots of good geometric calculators on the web. All you have to do is plug in the numbers.
Have fun!!
Swimmer
3.14(Pi) x 1.5 x 1.5 = 7.065
7.065 is the area of a cross section of a 3 inch body tube.
Clear as mud? There are lots of good geometric calculators on the web. All you have to do is plug in the numbers.
Have fun!!
Swimmer
powderburner
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Swimmer was right on track with his notes.
I would also point out that there are also some subtle variations in this terminology where folks sometimes get a little mixed up.
What many people intend by their definitions is the maximum projected cross section area--- another way to say it is max FRONTAL area. This includes the 'pie are squared' for the body tube/nose cone (to which Swimmer referred), plus the frontal area of the fins (thickness x span x number of fins), plus the frontal area of the launch lug (if you want to get fussy), etc.
Speaking as an aerodynamicist (by training), cross-section means the area of the vehicle as measured in a mathematical plane that is perpendicular to the longitudinal axis. Cross section varies from the front of the vehicle to the tail end. This plots out graphically with the X-axis (horizontal) being vehicle length and the Y-axis (vertical) being local cross section at a given fuselage station or X-axis location.
For aircraft, we try to make the plotted area distribution increase smoothly, peak at the smallest possible value of maximum cross section, and then decrease smoothly back to zero. Obviously, there are configuration features that preclude a totally smooth area curve; things like inlets and exhausts tend to cause discontinuities in the curve. But you do the best you can.
There. That was $87 in change for a 3-cent question.
I would also point out that there are also some subtle variations in this terminology where folks sometimes get a little mixed up.
What many people intend by their definitions is the maximum projected cross section area--- another way to say it is max FRONTAL area. This includes the 'pie are squared' for the body tube/nose cone (to which Swimmer referred), plus the frontal area of the fins (thickness x span x number of fins), plus the frontal area of the launch lug (if you want to get fussy), etc.
Speaking as an aerodynamicist (by training), cross-section means the area of the vehicle as measured in a mathematical plane that is perpendicular to the longitudinal axis. Cross section varies from the front of the vehicle to the tail end. This plots out graphically with the X-axis (horizontal) being vehicle length and the Y-axis (vertical) being local cross section at a given fuselage station or X-axis location.
For aircraft, we try to make the plotted area distribution increase smoothly, peak at the smallest possible value of maximum cross section, and then decrease smoothly back to zero. Obviously, there are configuration features that preclude a totally smooth area curve; things like inlets and exhausts tend to cause discontinuities in the curve. But you do the best you can.
There. That was $87 in change for a 3-cent question.
Powderburner,
Math was never my forte but since this hobby has overtaken me Ive found myself dealing with spheres, ellipse, trapazoids, circles, thrust, acceleration, velocity and on and on. I am really enjoying the mental olympics and building rockets.
Swimmer
Math was never my forte but since this hobby has overtaken me Ive found myself dealing with spheres, ellipse, trapazoids, circles, thrust, acceleration, velocity and on and on. I am really enjoying the mental olympics and building rockets.
Swimmer
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well (couldn't resist...
)my pie are round. my cake are squared, but my pie are round!
powderburner
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harrrrrumph!
havoc821
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I feel kind of dumb now. We have a mentor at scool that is helping us with our altitude projeect, and didn't know he was coming today, so thanks for going into ALL that detail. you really didn't have to because I found out the momen I posted the message. Thanks anyways.
JIM!!!
NO NO NO cakes are round also, the quote is
Cornbread are square, Pie are Round
But seriously: Powderburner:
When figuring the frontal area of a tapered shroud, you still use the visible area at a given y-section correct? The Max frontal area would be at the base (wides point) of the y-section transition plus all the fin, lug and other sticky outies frontal areas?
I just love the technical terms
NO NO NO cakes are round also, the quote is
Cornbread are square, Pie are Round
But seriously: Powderburner:
When figuring the frontal area of a tapered shroud, you still use the visible area at a given y-section correct? The Max frontal area would be at the base (wides point) of the y-section transition plus all the fin, lug and other sticky outies frontal areas?
I just love the technical terms
