Hi Joe,
Thanks for the in depth explanation and though at first sight it appears that the simple windmilling formula is out by a factor of 2 it might also just be that it is correct for windmills when the appropriate factors are selected !
Since windmills are tall and slim (50 feet not including sails) and generally set on a very exposed position on top of a hill or upward hill slope to deliberatley catch the wind then the various factors that you have quoted above could just about get you to the values quoted in the old timer windmilling formula to which I made reference above.
I think that the principals you outline above are much the same as used in Europe today for general building design and your point is well made that it might pay to get professional help on such matters.
Regards
Ken Hume
