Return-Path: <marv@lancaironline.net>
Received: from [65.33.166.167] (account <marv@lancaironline.net>)
  by logan.com (CommuniGate Pro WebUser 4.0b8)
  with HTTP id 1790938 for <lml@lancaironline.net>; Wed, 25 Sep 2002 17:31:58 -0400
From: "Marvin Kaye" <marv@lancaironline.net>
Subject: Re: [LML] Re: RAM-air induction 
To: lml
X-Mailer: CommuniGate Pro Web Mailer v.4.0b8
Date: Wed, 25 Sep 2002 17:31:58 -0400
Message-ID: <web-1790938@logan.com>
In-Reply-To: <200209251945.g8PJjtQ22088@localhost.localdomain>
MIME-Version: 1.0
Content-Type: text/plain; charset="ISO-8859-1"; format="flowed"
Content-Transfer-Encoding: 8bit

Posted for "Paul Davis" <pdavis@bmc.com>:

>>>>> On Wed, 25 Sep 2002, "Lorn" == Lorn H. Olsen wrote:

    Lorn> Thank you for the very clear and understandable post.
    Lorn> However, I believe that you have a problem in that the area
    Lorn> listed above sould be: PI * r^2. With a 3 inch diameter
    Lorn> opening, the wrong calculation leads to an answer 2 times as
    Lorn> large as it should be.

    Lorn> eg.      1/2  *  3^2  *  PI = 14.14
    Lorn>     and   PI * 1.5^2         =  7.07

When I first read what you posted I thought you were saying the area
is 7.07, but I see that the entire expansion is:

    0.5 * 3.1416 * 1.5**2 = 0.5 * 3.1416 * 2.25 = 3.5343

Yes?

-------------------
Paul Davis
Lancair Legacy builder
pdavis@bmc.com
Phone 713-918-1550


[Actually, no.  The formula says Pi * R^2.  If the diameter of the opening is 
3", then the formula becomes Pi * (3/2)^2... you can't take the .5 ( /2) 
factor twice.  According to the order of operations rules you do the stuff 
inside the parentheses first (ie, define the radius), then the powers, so 1.5" 
* 1.5" = 2.25si.... then multiply out the rest 3.1416 * 2.25si = 7.07si.

        <Marv>              ]