One point which Hank made has been unappreciated.
Wind is not a laminar flow of air. It is highly turbulent at the scale we
are dealing with. None of the calculations we are
talking about have much to do with modeling actual behavior of air against
metal. (I'll claim this area of expertise; my degree is
in atmospheric physics and fluid mechanics.)
Rather, long (sometimes tragic) experience has resulted in rules of gross
approximation which, when applied, result in structures
that fail very infrequently -- so infrequently that affordable insurance can be
obtained and "non-stop services" can run pretty much
non-stop. For towers and their loads, the rules of approximation are those
described in the building codes and the TIA spec.
Follow the calculation method described. (This is not my area of expertise. I
look to P.E.s like Hank for this part.)
Don't try to "improve it" to "better reflect reality". That's akin to
trying to measure a mud puddle's diameter with a
micrometer, when all we want to do is lay a long enough board over the mud
puddle to cross without messing up our shoes.
-- Eric K3NA
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