X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mail09.syd.optusnet.com.au ([211.29.132.190] verified) by logan.com (CommuniGate Pro SMTP 5.0.9) with ESMTPS id 1090645 for flyrotary@lancaironline.net; Wed, 03 May 2006 17:17:19 -0400 Received-SPF: none receiver=logan.com; client-ip=211.29.132.190; envelope-from=lendich@optusnet.com.au Received: from george (d58-104-192-21.dsl.nsw.optusnet.com.au [58.104.192.21]) by mail09.syd.optusnet.com.au (8.12.11/8.12.11) with SMTP id k43LGTj0021125 for ; Thu, 4 May 2006 07:16:30 +1000 Message-ID: <001f01c66ef6$df477450$15c0683a@george> From: "george lendich" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Muffler Date: Thu, 4 May 2006 07:16:40 +1000 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2800.1106 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Ed, It was Bill Jepson's idea actually, but like yourself I quickly saw the benefit. There are six cones in our design, however 4 of these form the front and exit, only 2 (as described) form the shock wave redirector. My limited knowledge leads me to believe with the shock wave redirected and scrubbing the surfaces of the muffler, the shock wave is turned into heat, with cooling internally and externally, to help manage the heat. Mistral uses cooling tube around the exhaust manifold tube with forced ait into that. Another good idea IMHO. Combining all of these ideas would be great, but at some stage you have to weigh the benefit of the outcome against the weight of the exhaust. Not to mention the complexity and cost of the unit. George (down under) > I like the idea, George. I think that is the "secret" is to keep the shock > wave from having a clean shot out the muffler but yet not restrict gas > flow - thanks for the suggestions. > > Ed > > Ed, > > I understood what you ment! > > > > I personally feel that the second of each pair of cones may cause too > > much > > restriction through turbulence. I understand what your saying about > > possibly > > making the second one bigger with holes - I unsure how that would work - > > seems a bit restrictive to me. > > > > If you join the two open ends of the cones it would make for a smoother > > transition, but still allow for the expansion area you are wanting, > > between > > each joined pair. > > > > Also no raw edges for the exhaust to chew away at. > > > > Bill's and mine only have one of these (pair) of cones in the muffler - > > it's > > job is to redirect the shock wave from directly seeing the exhaust exit. > > > > George (down under) > > > >> George, here was my idea of a muffler using cones. The centre (smaller) > >> tube is perforated with the cone attached to it. Room at the widest part > > of > >> the cone and wall of outer tube for gas to pass. A variation was to have > >> the cone extend to the outer tube wall and have all cones facing the > > header > >> end of the muffler only permitting gas (and sound) through the perforated > >> centre tube. > >> > >> Ed > >> ----- Original Message ----- > >> From: "george lendich" > >> To: "Rotary motors in aircraft" > >> Sent: Tuesday, May 02, 2006 7:42 PM > >> Subject: [FlyRotary] Re: new hangar > >> > >> > >> > Ed, > >> > My sentiments exactly - they will soon look a bit worse for wear. > >> > I can obviously source them from here but you will be better served if > > you > >> > can source them locally - some of ours may in fact come from the US. > >> > > >> > If you give me a size I will get you a price, what I find the most > >> > expensive > >> > is the cost of postage to the USA. > >> > Bob may also have the answer! If he has a contact perhaps you could get > >> > them > >> > made out of 321SS > >> > George > >> > > >> >> How about a source for the more reasonable priced cones, George. I > >> >> obviously don't care about the finish since they will go inside - just > >> >> the > >> >> material and cost. Thanks > >> >> > >> >> Ed > >> >> ----- Original Message ----- > >> >> From: "george lendich" > >> >> To: "Rotary motors in aircraft" > >> >> Sent: Tuesday, May 02, 2006 12:11 AM > >> >> Subject: [FlyRotary] Re: new hangar > >> >> > >> >> > >> >> > Ed, > >> >> > That's way too dear, you should be able to get them for about $10 US > >> >> > ea. > >> > I > >> >> > must admit I had to shop around as well. The ones I ended up with > >> > weren't > >> >> > as > >> >> > perfectly finished as the expensive one but the same material 316SS. > >> >> > Our design has an inner cooling tube and an outer cooling tube and > > heat > >> >> > shield, all the ends are cones as well! > >> >> > All I have to do is get my welder to finish it. > >> >> > George > >> >> > > >> >> > George ( down under) > >> >> > > >> >> >> Sounds like the right formula, George - will wait for your > >> >> >> project's > >> >> > outcome > >> >> >> before I try cones. Yes, I did find some cone inserts at $60.00 > > USD > >> >> > each. > >> >> >> I would need 4 for my two tubes - hummm makes one tube sound better > >> >> >> all > >> >> > the > >> >> >> time. > >> >> >> > >> >> >> Ed > >> >> >> > >> >> >> ----- Original Message ----- > >> >> >> From: "george lendich" > >> >> >> To: "Rotary motors in aircraft" > >> >> >> Sent: Monday, May 01, 2006 7:48 PM > >> >> >> Subject: [FlyRotary] Re: new hangar > >> >> >> > >> >> >> > >> >> >> > > >> >> >> >> Just the shells, TJ, the 1/8" thick SS washers are history. I > > have > >> >> >> >> concluded that no reasonable thickness of metal will stand up to > >> >> >> >> the > >> >> >> > exhaust > >> >> >> >> pulse for long if it is perpendicular to the shock wave. I > > believe > >> >> > that > >> >> >> > if > >> >> >> >> I could shape them into cones where by the shock wave would hit > > the > >> >> > side > >> >> >> > of > >> >> >> >> the cone at an oblique angle would probably survive - now all > >> >> >> >> I > >> > have > >> >> > to > >> >> >> > do > >> >> >> >> is find some {:>). > >> >> >> >> > >> >> >> >> Ed > >> >> >> > > >> >> >> > Ed, > >> >> >> > There plenty of SS cones available in 1.6mm, I'm using them in my > >> >> > exhaust > >> >> >> > which is a joint venture design with Bill Jepson - the idea is to > >> >> > redirect > >> >> >> > the shock waves but not restrict the exhaust, as you have alluded > >> >> >> > to. > >> >> >> > George ( down under) > >> >> >> > > >> >> >> > > >> >> >> > -- > >> >> >> > Homepage: http://www.flyrotary.com/ > >> >> >> > Archive and UnSub: > > http://mail.lancaironline.net/lists/flyrotary/ > >> >> >> > > >> >> >> > >> >> >> > >> >> >> > >> >> >> -- > >> >> >> Homepage: http://www.flyrotary.com/ > >> >> >> Archive and UnSub: http://mail.lancaironline.net/lists/flyrotary/ > >> >> > > >> >> > > >> >> > -- > >> >> > Homepage: http://www.flyrotary.com/ > >> >> > Archive and UnSub: http://mail.lancaironline.net/lists/flyrotary/ > >> >> > > >> >> > >> >> > >> >> > >> >> -- > >> >> Homepage: http://www.flyrotary.com/ > >> >> Archive and UnSub: http://mail.lancaironline.net/lists/flyrotary/ > >> > > >> > > >> > -- > >> > Homepage: http://www.flyrotary.com/ > >> > Archive and UnSub: http://mail.lancaironline.net/lists/flyrotary/ > >> > > >> > > > > > > -------------------------------------------------------------------------- -- > > ---- > > > > > >> -- > >> Homepage: http://www.flyrotary.com/ > >> Archive and UnSub: http://mail.lancaironline.net/lists/flyrotary/ > >> > > > > > > -- > > Homepage: http://www.flyrotary.com/ > > Archive and UnSub: http://mail.lancaironline.net/lists/flyrotary/ > > > > > > -- > Homepage: http://www.flyrotary.com/ > Archive and UnSub: http://mail.lancaironline.net/lists/flyrotary/