From: "Marvin Kaye" <marv@lancaironline.net>
Subject: Re: [LML] Re: Vortex Generators
To: lml
Date: Wed, 03 Dec 2003 21:47:59 -0500
Message-ID: <web-2782689@logan.com>
In-Reply-To: <003601c3ba0c$f8990e60$4f00a8c0@paul>
MIME-Version: 1.0
Content-Type: text/plain; charset="ISO-8859-1"; format="flowed"
Content-Transfer-Encoding: 8bit

Posted for "Paul Nafziger" <naf@britevalley.com>:

Vortex generators create turbulent boundary layer flow, essentially adding
energy to the boundary layer.  This does indeed re-attach flow if it
separates, or rather prevent the flow from separating in the first place.
Also, they do indeed ruin the laminar flow we all strive to attain.  

Also, imparting that energy to the boundary layer comes at a cost, which is
increased drag under normal conditions.  (When flow is separated, it's
another story).  Hence my question, why are we interested in doing that to
these high performance airplanes?  I understand that you can lower your
stall speed, but who wants to do that at the expense of decreased
performance?

Naf

Paul Nafziger
LNC2 N7PN

> It would seem that the generators would ruin the laminar flow 
> at reduced angles of attack, as in cruise?