Towertalk
[Top] [All Lists]

[TowerTalk] Formula?

To: <towertalk@contesting.com>
Subject: [TowerTalk] Formula?
From: Hank.Lonberg@harrisgrp.com (Hank Lonberg)
Date: Fri, 29 May 1998 8:04 -0800
     Chris:
     
     In the "Uniform Building Code" used in the US the wind pressure is a 
     function of a variable called the stagnation wind pressure, Qs. This 
     wind pressure is modified by factors such as exposure, or fetch, and 
     height above the ground and the geometric shape of the particular 
     structure in question.
     
     This stagnation wind pressure value, Qs, is a function of the wind 
     velocity. In the old imperial units, miles per hour, is as follows;
     
     Qs = 1/2 Rho V*V   where Rho is the mass density of air 
                                and V is wind velocity.
     
     This is also Bernoulli's equation.
     
     reduced to usable values this translates to 
     
     Qs= 0.00256*V*V  when V is in miles per hour
                        Qs is  pounds per square foot.
     
     don't forget that you can reduce the value due to geometric shape of 
     structure. In the case of an antenna assuming a round cross section 2 
     inches or less in diameter it is apporpriate to use a factor of 0.8

Hope this helps.

Hank / KR7X


______________________________ Reply Separator _________________________________
Subject: [TowerTalk] Formula?
Author:  K7LXC@aol.com at ~INETMAIL
To: <towertalk@contesting.com>
Date:    5/28/98 1:09 PM


>From Chris, ZS6EZ --
     
" I'm looking for the proportionality constant (c) that relates wind 
speed (v) and antenna surface area (A) to the lateral force on the 
antenna (F), i.e. F = cAv.
Any ideas, please? "
     
Tnx, Chris ZS6EZ
     
--
FAQ on WWW:               http://www.contesting.com/towertalkfaq.html 
Submissions:              towertalk@contesting.com
Administrative requests:  towertalk-REQUEST@contesting.com 
Problems:                 owner-towertalk@contesting.com
Search:                   http://www.contesting.com/km9p/search.htm 
------------------------- Original message header:
>MAIL FROM:<owner-towertalk@contesting.com> 
>RCPT TO:<hank.lonberg@harrisgrp.com>
>DATA
>Received: from dayton.akorn.net (dayton.akorn.net [205.217.100.11])     by dayt
on.akorn.net (8.8.5/8.8.5) with SMTP id NAA05875;     Thu, 28 May 1998 13:10:06 
-0400 (EDT)
>Received: by dayton.akorn.net (TLB v0.10a (1.23 tibbs 1997/01/09 00:29:32)); Th
u, 28 May 1998 13:09:56 -0400 (EDT)
>From: K7LXC@aol.com
>Message-ID:<751f5818.356d9a3f@aol.com> 
To: <towertalk@contesting.com>
>Date: Thu, 28 May 1998 13:09:18 EDT
>To: towertalk@contesting.com, crb@nanoteq.com 
>Mime-Version: 1.0
>Subject: [TowerTalk] Formula?
>Content-type: text/plain; charset=US-ASCII 
>Content-transfer-encoding: 7bit
>X-Mailer: AOL 3.0 for Windows 95 sub 64 
>Sender: owner-towertalk@contesting.com 
>Precedence: bulk
>X-List-Info: http://www.contesting.com/towertalkfaq.html 
>X-Sponsor: W4AN, KM3T, N5KO & AD1C
------------------------- End of message header.

--
FAQ on WWW:               http://www.contesting.com/towertalkfaq.html
Submissions:              towertalk@contesting.com
Administrative requests:  towertalk-REQUEST@contesting.com
Problems:                 owner-towertalk@contesting.com
Search:                   http://www.contesting.com/km9p/search.htm

<Prev in Thread] Current Thread [Next in Thread>