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Reply-To: "kevin lane" <n3773@comcast.net>
From: "kevin lane" <n3773@comcast.net>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
References: <list-855413@logan.com>
Subject: Re: [FlyRotary] Re: class in curves
Date: Tue, 5 Apr 2005 10:17:26 -0700
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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