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klokes
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Homework Statement
In designing a hemispherical parachute, i´ve come across conflicting information regarding whatever to use a constructed (ortographical projection) vs. a nominal diameter in calculating the necessary area required in the parachute.
Sources using constructed diameter in equations:
http://en.wikipedia.org/wiki/Drag_(physics)
http://my.execpc.com/~culp/rockets/descent.html
http://physics.info/drag/
Plus a few more.
The main source promoting a nominal diameter is a specialist professor in the area, making me doubt my previous decision to use a constructed diameter (which seems physically reasonable):
http://www.pcprg.com/rounddes.pdf
Homework Equations
The equation for drag, computed from a mix of bernoullis equation and pressure over an area, with a coefficient for drag resistance added, C.
F= 1/2×c×p×v^2×A
The Attempt at a Solution
Choosing the constructed diameter in my further equations, because of the assumption that an inclined surface should, because of the steep angle of approach relative the air-particles, affect them (summarized) in an ortographical manner. The paper is due friday, and thus i would very much appreciate a quick answer.
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