[TowerTalk] Wind Surface Area estimates

[Jim Lux]

On 3/9/12 10:32 AM, Gary Slagel wrote:
> Shoot... using the .707 figure for 45 deg I'm back right at the worst
> case scenario. Where does the .707 come from?

cosine (45 degrees)

That's the projected area in the direction of the wind coming from 45 
degrees off axis.



> I was using a simplified version of windload calcs from the force 12 web
> site that goes something like '..wind load is either the total element
> wind load OR the boom windload, whichever is the larger resistance to
> the wind....'.


That's probably not a very valid approach.  Some sort of "projected 
area" is more valid, but neglects the skin friction along the axis of 
the tube.