X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from poplet2.per.eftel.com ([203.24.100.45] verified) by logan.com (CommuniGate Pro SMTP 5.2.16) with ESMTP id 3884020 for flyrotary@lancaironline.net; Tue, 13 Oct 2009 00:25:56 -0400 Received-SPF: none receiver=logan.com; client-ip=203.24.100.45; envelope-from=lendich@aanet.com.au Received: from sv1-1.aanet.com.au (sv1-1.per.aanet.com.au [203.24.100.68]) by poplet2.per.eftel.com (Postfix) with ESMTP id 0510A173B63 for ; Tue, 13 Oct 2009 12:25:15 +0800 (WST) Received: from ownerf1fc517b8 (203.171.92.134.static.rev.aanet.com.au [203.171.92.134]) by sv1-1.aanet.com.au (Postfix) with SMTP id 86A48BEC005 for ; Tue, 13 Oct 2009 12:25:13 +0800 (WST) Message-ID: From: "George Lendich" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] where's the missing power? Date: Tue, 13 Oct 2009 14:25:13 +1000 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0020_01CA4C10.FA199A10" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.5843 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5579 X-Antivirus: avast! (VPS 091012-0, 10/12/2009), Outbound message X-Antivirus-Status: Clean This is a multi-part message in MIME format. ------=_NextPart_000_0020_01CA4C10.FA199A10 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Kelly, My apologies, Yep! great idea when using a muffler. Can make a really = long muffler as well. I can visualize now what your getting at with the = cross over two muffler system cooled by outer covers with forward = inlets, should look cool as well.=20 =20 I have always like the inlets of the Mistral test aircraft with their = jet style inlets. I assume yours would look similar? Different aircraft = I know. George George, I am sure you are correct in your assesment concerning sound if = implemented without a muffler system included................Have you ever heard = the 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 = muffler of 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 gain 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 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 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" = system (In my "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 also !!.............I=20 know this is splitting hairs but I am planning on splitting my = exhaust after 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 cooling air) on each=20 side of the "V" ) and I wonder what size you would use from the = 2.75" to branch 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 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.=20 I will make some drawings. Lynn E Hanover ------=_NextPart_000_0020_01CA4C10.FA199A10 Content-Type: text/html; charset="utf-8" Content-Transfer-Encoding: quoted-printable =EF=BB=BF
Kelly,
My apologies, Yep! great idea when = using a muffler.=20 Can make a really long muffler as well. I can visualize now = what your=20 getting at with the cross over two muffler system cooled by outer covers = with=20 forward inlets, should look cool as well. 
 
I have always like the inlets of the = Mistral test=20 aircraft with their jet style inlets. I assume yours would look similar? = Different aircraft I know.
George
George,
    I am sure you are correct in your assesment = concerning=20 sound if implemented
without a muffler system included................Have you ever = heard the=20 exhaust
noise the piston powered "Aero Commander" twin engined a/c make = using=20 such
a "Augmentation" system.............I do not know for sure there = is a=20 muffler in their
system but I do not think there is...............I am sure that a = muffler=20 of some kind
will be needed................My hope is to reduce the drag of = the=20 external exhaust
system by enclosing  it in the large semi buried tubes and = perhaps=20 even gain a
small amount of thrust from the air flowing through it being=20 heated............
 
  Probably just wishful thinking on my = part!! 
--
Kelly Troyer
"Dyke = Delta"_13B=20 ROTARY Engine
"RWS"_RD1C/EC2/EM2
"Mistral"_Backplate/Oil = Manifold=20



 
--------------=20 Original message from "George Lendich" <lendich@aanet.com.au>: = --------------

=EF=BB=BF
Kelly,
I think what your referring to is = exhaust=20 augmentation whereby an exhaust tube runs into another open tube, = creating a=20 negative pressure sucking in air around the front end of the larger = open=20 tube. This is very successful with extracting air from the cowl -=20 however it won't suppress sound, most likely it make it louder = with=20 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"=20 system (In my "Delta's" case
one on each side of the bottom "V") consisting of large=20 diameter tubes (5-6" ?) exiting
behind the cockpit with 2" tubes down the middle and open=20 to forward motion and prop
blast would do to noise level ??............. 
 
 
--
Kelly Troyer
"Dyke = Delta"_13B=20 ROTARY Engine
"RWS"_RD1C/EC2/EM2
"Mistral"_Backplate/Oil = Manifold=20



 
--------------=20 Original message from Lynn Hanover <lehanover@gmail.com>:=20 --------------

Lynn,
   I would like to see a = drawing and I am=20 sure others of the group would also !!.............I
know this is splitting hairs but I am = planning on=20 splitting my exhaust after the collector to two
mufflers (no good reason other than the = Dyke Delta=20 bottom skin has a "Keel" shape (V)
and I want to keep the bottom symmetrical = with a=20 muffler (recessed with cooling air) on each
side of the "V" ) and I wonder what size = you would=20 use from the 2.75" to branch off to the mufflers=20 ??......... 
 
Again Thanks,
 
Kelly Troyer
"Dyke Delta"_13B ROTARY = Engine=20
"RWS"_RD1C/EC2/EM2
"Mistral"_Backplate/Oil Manifold =
 
The single pipe would about 5.9 square = inches. A 2"=20 tube would be 3.14 square inches. So I would use 2 inch tubing. = Most=20 modern V-8s have a combiner "X" fitting in the center of the two = pipe=20 system. It produces lower back pressure and a less harsh tone. =
 
I will make some drawings.
 
Lynn E = Hanover
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