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From: "Ed Anderson" <eanderson@carolina.rr.com>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
References: <list-855846@logan.com>
Subject: Re: [FlyRotary] Re: class in curves
Date: Tue, 5 Apr 2005 18:24:35 -0400
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Kevin,  you are giving me more credit than deserved - I don't have any
magical formula that I am keeping from you.  I will have to go back to my
mess of CAD drawings and see if I can find the actual CAD drawing I printed
those from.  Perhaps that will refresh my limited memory capacity on what I
actually did.  I'll let you know what I find.

Ed

----- Original Message -----
From: "kevin lane" <n3773@comcast.net>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Sent: Tuesday, April 05, 2005 1:17 PM
Subject: [FlyRotary] Re: class in curves


> Ed - I can see the 7 degree tangent line concept.  What I don't follow is
> the idea that the next tangent comes off the prior line a certain distance
> away.  With these tangency origin points far apart the generated spline
> curve  is gentle.  As the points of tangency are pushed closer together
the
> curve gets tighter.  There must also be some ratio of delta X to delta Y
> along the curve to stay within the bounds of non-separation, right?  I
> suppose that ration is based on air speed?
>     Freightliner is building a full-scale wind tunnel in Portland.  I wish
I
> could take my plane over and see what is really going on inside.
> Kevin Lane  Portland, OR
> e-mail-> n3773@comcast.net
>
> ----- Original Message -----
> From: "Ed Anderson" <eanderson@carolina.rr.com>
> To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
> Sent: Tuesday, April 05, 2005 5:41 AM
> Subject: [FlyRotary] Re: class in curves
>
>
> > Kevin,
> >
> > Its been a while, but  what I was doing was first, drawing an
approximate
> > curve based on a truncated Streamline duct.  Then adjusting it mainly by
> > eye
> > from inlet to core to fit my space constraints.  Then I used a CAD
program
> > to plot lines of tangent and varied from one tangent line to the next by
> > approx 7 deg. (some figure from NACA wind tunnel testing data).  If the
> > tangent lines pretty well match my curve in a region I kept the curve,
if
> > it
> > varied too much then I adjusted my curve (by eyeball) to more closely
> > follow
> > the tangent line.  That's the best I can recall of the process.
> >
> > Ed
> >
> >
> > ----- Original Message -----
> > From: "kevin lane" <n3773@comcast.net>
> > To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
> > Sent: Tuesday, April 05, 2005 12:57 AM
> > Subject: [FlyRotary] class in curves
> >
> >
> >> Ed - I am building intakes right now and noticed in your photo many
> > tangent
> >> lines you used to derive your shapes.  I'd love a quick lesson on what
> >> you
> >> are doing.  I've been simply mocking what I think sorta' looks the
same.
> >> Since I am taking AutoCAD classes I could design stuff to any accuracy.
> > I'm
> >> guessing that your lines are some type of maximum curvature limits to
> > avoid
> >> separation?  I always wondered how one measured degrees of curvature on
a
> >> curve.  I know, like you don't have enough to do ! :-)
> >> Kevin Lane  Portland, OR
> >> e-mail-> n3773@comcast.net
> >>
> >>
> >> >>  Homepage:  http://www.flyrotary.com/
> >> >>  Archive:   http://lancaironline.net/lists/flyrotary/List.html
> >>
> >
> >
> >
> >>>  Homepage:  http://www.flyrotary.com/
> >>>  Archive:   http://lancaironline.net/lists/flyrotary/List.html
>
>
> >>  Homepage:  http://www.flyrotary.com/
> >>  Archive:   http://lancaironline.net/lists/flyrotary/List.html
>