Quote:
Originally Posted by aerohead
The open-faced strut would behave much like angle iron in the airstream.I don't have that with me,but I believe that the Cd is over 1.00.
The jet created would be asymmetrical with respect to the mirrors wake and could possibly make things worse.
The mirror in free flight would be Cd 0.30 - 0.25
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*All I could find was a sub-critical Reynolds number Cd for an angle iron section,normal to the flow,with no slant.It is given Cd 2.2 by Hoerner.
*Cd 2.0 if a solid section.
*Turned with pointed part into the wind,Cd 1.45.
*Ditto,with solid section,Cd 1.55.
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The only structure shown with sub,and supercritcal Reynolds number was for a circular rod section.
* subcritical = Cd 1.2
*supercritical = Cd 0.35 (only 29.1% of the sub-critical Cd)
There's no telling if any of the other structures would behave the same,but for estimation purposes,it may be all we can do.
*As to the slant,you might just do a simple force diagram and use the Pythagoriun theorem to get velocity vector values angled,and use them with the Cd.