X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from fmailhost05.isp.att.net ([204.127.217.105] verified) by logan.com (CommuniGate Pro SMTP 5.2.16) with ESMTP id 3883971 for flyrotary@lancaironline.net; Mon, 12 Oct 2009 23:16:09 -0400 Received-SPF: none receiver=logan.com; client-ip=204.127.217.105; envelope-from=keltro@att.net DKIM-Signature: v=1; q=dns/txt; d=att.net; s=dkim01; i=keltro@att.net; a=rsa-sha256; c=relaxed/relaxed; t=1255403770; h=Content-Type: MIME-Version:In-Reply-To:Message-Id:Date:Subject:To:From; bh=zCR3kK CYvjwAM9VOdBu+KCnvx0b2uD33WNz4kOVH4Yo=; b=m7K2x+blGa9sZvQYqUB8H0q3k 1FgCcs4VvKMp10y+ltriPfjK4JshMKOojz4IarMh+FbLOEWVHNQY9Sq8jdvcQ== Received: from fwebmail03.isp.att.net ([204.127.218.103]) by isp.att.net (frfwmhc05) with SMTP id <20091013031535H05003ebfqe>; Tue, 13 Oct 2009 03:15:35 +0000 X-Originating-IP: [204.127.218.103] Received: from [208.114.34.233] by fwebmail03.isp.att.net; Tue, 13 Oct 2009 03:15:34 +0000 From: "Kelly Troyer" To: "Rotary motors in aircraft" Subject: where's the missing power? Date: Tue, 13 Oct 2009 03:15:34 +0000 Message-Id: <101320090315.26710.4AD3F0D6000767390000685622230647629B0A02D29B9B0EBF019D9B040A05@att.net> In-Reply-To: X-Mailer: AT&T Message Center Version 1 (Mar 2 2009) X-Authenticated-Sender: a2VsdHJvQGF0dC5uZXQ= MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="NextPart_Webmail_9m3u9jl4l_26710_1255403734_0" --NextPart_Webmail_9m3u9jl4l_26710_1255403734_0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable George, I am sure you are correct in your assesment concerning sound if impleme= nted without a muffler system included................Have you ever heard the ex= haust noise the piston powered "Aero Commander" twin engined a/c make using such a "Augmentation" system.............I do not know for sure there is a muffl= er in their system but I do not think there is...............I am sure that a muffler o= f some kind=20 will be needed................My hope is to reduce the drag of the external= exhaust=20 system by enclosing it in the large semi buried tubes and perhaps even gai= n a=20 small amount of thrust from the air flowing through it being heated........= .... Probably just wishful thinking on my part!!=20 -- Kelly Troyer=20 "Dyke Delta"_13B ROTARY Engine=20 "RWS"_RD1C/EC2/EM2=20 "Mistral"_Backplate/Oil Manifold=20 -------------- Original message from "George Lendich" : --------------=20 =EF=BB=BF=20 Kelly, I think what your referring to is exhaust augmentation whereby an exhaust t= ube runs into another open tube, creating a negative pressure sucking in ai= r around the front end of the larger open tube. This is very successful wit= h extracting air from the cowl - however it won't suppress sound, most like= ly it make it louder with sound waves escaping through the front open end. If I understand you correctly. George ( down under) Lynn, Another thought.............What do you think an "Extractor" system (In m= y "Delta's" case one on each side of the bottom "V") consisting of large diameter tubes (5-6= " ?) exiting=20 behind the cockpit with 2" tubes down the middle and open to forward motion= and prop blast would do to noise level ??.............=20 -- Kelly Troyer=20 "Dyke Delta"_13B ROTARY Engine=20 "RWS"_RD1C/EC2/EM2=20 "Mistral"_Backplate/Oil Manifold=20 -------------- Original message from Lynn Hanover : --= ------------=20 Lynn,=20 I would like to see a drawing and I am sure others of the group would al= so !!.............I=20 know this is splitting hairs but I am planning on splitting my exhaust afte= r the collector to two=20 mufflers (no good reason other than the Dyke Delta bottom skin has a "Keel"= shape (V) and I want to keep the bottom symmetrical with a muffler (recessed with coo= ling air) on each=20 side of the "V" ) and I wonder what size you would use from the 2.75" to br= anch off to the mufflers ??.........=20 Again Thanks, Kelly Troyer=20 "Dyke Delta"_13B ROTARY Engine=20 "RWS"_RD1C/EC2/EM2=20 "Mistral"_Backplate/Oil Manifold=20 The single pipe would about 5.9 square inches. A 2" tube would be 3.14 squa= re inches. So I would use 2 inch tubing. Most modern V-8s have a combiner "= X" fitting in the center of the two pipe system. It produces lower back pre= ssure and a less harsh tone.=20 I will make some drawings. Lynn E Hanover --NextPart_Webmail_9m3u9jl4l_26710_1255403734_0 Content-Type: multipart/related; boundary="NextPart_Webmail_9m3u9jl4l_26710_1255403734_1" --NextPart_Webmail_9m3u9jl4l_26710_1255403734_1 Content-Type: text/html; charset="utf-8" Content-Transfer-Encoding: quoted-printable
George,
    I am sure you are correct in your assesment concern= ing sound if implemented
without a muffler system included................Have you ever heard t= he exhaust
noise the piston powered "Aero Commander" twin engined a/c make using = such
a "Augmentation" system.............I do not know for sure there is a = muffler in their
system but I do not think there is...............I am sure that a muff= ler of some kind
will be needed................My hope is to reduce the drag of the ext= ernal exhaust
system by enclosing  it in the large semi buried tubes and perhap= s even gain a
small amount of thrust from the air flowing through it being heated...= .........
 
  Probably just wishful thinking on my part!! 
--
Kelly Troyer
"Dyke Delta"_1= 3B ROTARY Engine
"RWS"_RD1C/EC2/EM2
"Mistral"_Backplate/Oil Manifol= d



 
-------------- Original message from "George Lendich" <le= ndich@aanet.com.au>: --------------

=EF=BB=BF
Kelly,
I think what your referring to is exhaust = augmentation whereby an exhaust tube runs into another open tube, creating = a negative pressure sucking in air around the front end of the larger open = tube. This is very successful with extracting air from the cowl - however&n= bsp;it won't suppress sound, most likely it make it louder with sound waves= escaping through the front open end.
If I understand you correctly.
George ( down under)
Lynn,
  Another thought.............What do you think an "Extractor" sy= stem (In my "Delta's" case
one on each side of the bottom "V") consisting of large diameter&= nbsp;tubes (5-6" ?) exiting
behind the cockpit with 2" tubes down the middle and open to forw= ard motion and prop
blast would do to noise level ??............. 
 
 
--
Kelly Troyer
"Dyke Delta"_1= 3B ROTARY Engine
"RWS"_RD1C/EC2/EM2
"Mistral"_Backplate/Oil Manifol= d



 
-------------- Original message from Lynn Hanover <lehano= ver@gmail.com>: --------------

Lynn,
   I would like to see a drawing and I am = sure others of the group would also !!.............I
know this is splitting hairs but I am planning on sp= litting my exhaust after the collector to two
mufflers (no good reason other than the Dyke Delta b= ottom skin has a "Keel" shape (V)
and I want to keep the bottom symmetrical with a muf= fler (recessed with cooling air) on each
side of the "V" ) and I wonder what size you would u= se from the 2.75" to branch off to the mufflers ??......... 
 
Again Thanks,
 
Kelly Troyer
"Dyke Delta"_13B ROTARY Engine
= "RWS"_RD1C/EC2/EM2
"Mistral"_Backplate/Oil Manifold
 
The single pipe would about 5.9 square inches. A 2" = tube would be 3.14 square inches. So I would use 2 inch tubing. Most modern= V-8s have a combiner "X" fitting in the center of the two pipe system. It = produces lower back pressure and a less harsh tone.
 
I will make some drawings.
 
Lynn E Hanover
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