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From: "Ed Anderson" <eanderson@carolina.rr.com>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
References: <list-2504772@logan.com>
Subject: Re: [FlyRotary] exhausting work
Date: Mon, 26 Nov 2007 07:59:45 -0500
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Looks like it may have some merit  in muting the exhaust a bit.  The problem 
I had when experimenting with exhaust was that anything which presented a 
flat surface to the exhaust pulse simply did not live long.  Even 1/8" thick 
stainless steel plates were destroyed.  Now a cone or some shape that 
deflected rather than brute force tried to break up the exhaust pulse may 
well survive quite a bit longer.

I finally got tired to almost having success - the disks fabricated to look 
like a  pin wheel came the closest to being successful.  It really muted the 
exhaust, but the disks soon broke loose and beginning to spin like a turbine 
wheel in that exhaust and like a wind milling prop resisted the exhaust 
flow.  I ended up with EGT 150-200 deg higher than normal and  rpm limited 
to 6000.

  The first (ignored) clue  that the disks were spinning, was when  I was 
told by a hangar mate that on take off it sounded like I had a turbine under 
the cowl. Yeah, Yeah a poor man's turbine - a rotary, well it turned out he 
was right, it sounded like a turbine because the exhaust flow was being 
broken up by the spinning discs (and they were really spinning) at a very 
high rpm.

So I am now flying with HushPower II mufflers and I'll leave further 
experimenting with exhaust to a new spirit {:>)

ED
 ----- Original Message ----- 
From: "Charlie England" <ceengland@bellsouth.net>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Sent: Sunday, November 25, 2007 10:16 PM
Subject: [FlyRotary] exhausting work


> While re-perusing an old article to answer a question on another list, I 
> noticed something about coanda nozzles that might be of interest to rotary 
> fans. It mentions that while there is no performance increase, it does 
> seem to 'mellow' the exhaust sound. I wonder if this might survive the 
> rotary pulses better than other pulse breaking techniques & help take the 
> edge off the rotary bark. (Although it might be a moot point if everyone 
> adopts Dennis Haverlauh's system for the Renesis.)
>
> http://cafefoundation.org/v2/pdf_cafe_reports/EPG%20PART%20IV.pdf
>
> Charlie
>
> --
> Homepage:  http://www.flyrotary.com/
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