Re: Re:Aerodynamic obsessiveness

From: Nick Ray <lasray_at_gmail.com>
Date: Sun, 28 Jan 2007 15:49:00 -0500

Ray is a very sharp guy, and from every my models have shown me I
would have to agree with this. When I was relatively new to indoor, I
could not believe that many of the top flyers thought that rounding
square post and spars was an unnecessary waste of time, but have
trying models both ways, I have to agree. Furthermore, working on the
prop rubber combo will do far more than any amount of tweaking to
structural components. Something otherwise interesting to contemplate
might be taking strobe style pictures of a film covered model and
looking at just how much change in the covering you get from one
second to anther. It's this experiment that leads me to thinking that
skin drag generated from extra surface area will do more than the post
allow could if they were 1/8" square.
Two more cents into the Good Will though bucket,
Nick Ray


On 1/28/07, Brant Fredrickson <brantfredrickson_at_yahoo.com> wrote:
>
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>
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> Nick,
> There is a NFFS paper out there that Ray Harlan wrote on the drag
> components
> of a indoor model. Basically Ray reports on the measured components of
> total
> drag. He breaks them down into the following.
> 1. pressure drag - that do to the frontal area of the model components
> 2. induced drag - that do to the total lift of the model surfaces
> 3. skin friction - that do the all the surface area of the model
> components.
> He shows skin friction as the dominant component of the total drag and
> pressure drag to things like the wing posts as a minor component. I am not
> technical enough to determine if the story Ray tells in his paper is the
> real scoop, but it is supported by many comments I have hear from other
> veteran flyers and the little experience I have watching the flights of my
> sons' SO indoor models.
>
> www.BrantFredrickson.com
> mailto:RealEstate_at_BrantFredrickson.com
> Century 21 Homestar, Cleveland, Ohio
> home office 440-442-5866
> mobile 440-983-1173
> fax 440-442-3678
>
>
Received on Sun Jan 28 2007 - 12:49:02 CET