Return-Path: Received: from smtpauth07.mail.atl.earthlink.net ([209.86.89.67] verified) by logan.com (CommuniGate Pro SMTP 4.3c2) with ESMTP id 777420 for flyrotary@lancaironline.net; Wed, 09 Mar 2005 18:55:39 -0500 Received-SPF: neutral receiver=logan.com; client-ip=209.86.89.67; envelope-from=jerryhey@earthlink.net Received: from [65.176.161.180] (helo=earthlink.net) by smtpauth07.mail.atl.earthlink.net with asmtp (Exim 4.34) id 1D9B0w-00008S-57 for flyrotary@lancaironline.net; Wed, 09 Mar 2005 18:54:55 -0500 DomainKey-Signature: a=rsa-sha1; q=dns; c=simple; s=test1; d=earthlink.net; h=Date:Subject:Content-Type:Mime-Version:From:To:In-Reply-To:Message-Id:X-Mailer; b=sL9fjUBET1QOl2PzvxLbbI6yPZ7hprwz3VdQJZIZNpeKclrJ7h6S7bBV+LaSgeLF; Date: Wed, 9 Mar 2005 18:56:05 -0500 Subject: Re: [FlyRotary] Re: Different Tangential Mufflers Content-Type: multipart/alternative; boundary=Apple-Mail-2--1038620333 Mime-Version: 1.0 (Apple Message framework v552) From: Jerry Hey To: "Rotary motors in aircraft" In-Reply-To: Message-Id: X-Mailer: Apple Mail (2.552) X-ELNK-Trace: 8104856d7830ec6b1aa676d7e74259b7b3291a7d08dfec793c84af3a9520fee50f20d0e422110742350badd9bab72f9c350badd9bab72f9c350badd9bab72f9c X-Originating-IP: 65.176.161.180 --Apple-Mail-2--1038620333 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=ISO-8859-1; format=flowed Woops I got to correct myself. The skin area for the cool tube is 31.4=20= sq inches. The 187 sq. in. is for the six inch o.d. by 10 inch long =20 cylinder. Jerry On Wednesday, March 9, 2005, at 04:38 PM, Jerry Hey wrote: > Tracy, here is what I am hoping will happen. Heat will be pulled out=20= > of the exhaust gas by the additional skin area (187 sq inches)=20 > provided by the cool tube. This effect will be greatly magnified by=20 > the steady stream of high velocity cool air passing through the cool=20= > tube. As the exhaust gas looses temp, it also looses velocity. The=20 > exhaust pulses will weaken. Someone else, on the other list,=20 > calculated it would reduce inside muffler temps as much as 200=20 > degrees. That is what I am hoping will happen. It is hard for me to=20= > believe the cool tube would have no or very slight effect. Bob White=20= > is going to instrument his exhaust so that we can get some real=20 > numbers. Regards, Jerry > > > > On Wednesday, March 9, 2005, at 04:00 PM, Tracy Crook wrote: > >> =A0 >> I may not be understanding what the 2 rotor version (cool pipe going=20= >> all the way through) is supposed to accomplish or maybe my gut-feel=20= >> thermodynamic instincts are way off.=A0 I can't imagine this would = have=20 >> any significant effect on exhaust temps, muffler wall temp or sound.=A0= >> =A0 >> Tracy=A0 (been wrong more than once) >> =A0 >> =A0 >> Bill, from the picture you sent, it isn't clear to me where the 'cool=20= >> tube' ends inside the muffler.=A0 Give me a clue! >> >> =A0 >> Tracy >> >> >> Tracy, On the small muffler (2 rotor) the cool tube goes all the way=20= >> thru. The front of the tube needs a feed from the cowl.=A0The exit=20 >> needs a pipe=A0to the cowl exit although it could be very thin.=A0This = is=20 >> a sealed style like Jerry Hey and Ed Klepis have come up with. On the=20= >> 3 rotor pipe the cool tube stops just inside the tailpipe. The=20 >> section might be a little confusing as it shows a small support bar=20= >> that was suggested to prevent the internal pipe from sagging. The=20 >> sections I included should give a good indication. The intent is to=20= >> form a annulus that should draw air through the tube venturi style.=20= >> This needs only some clear space in front of the muffler. The idea is=20= >> that you should mix air in the tailpipe to A; cool the exhaust and=20 >> not burn the paint off the belly, and B; lessen the exhaust note by=20= >> absorbing some of the exhaust energy by mixing cooler air with the=20 >> exhaust. >> Bill Jepson >> =A0 >> --Apple-Mail-2--1038620333 Content-Transfer-Encoding: quoted-printable Content-Type: text/enriched; charset=ISO-8859-1 Woops I got to correct myself. The skin area for the cool tube is 31.4 sq inches. The 187 sq. in. is for the six inch o.d. by 10 inch long cylinder. Jerry On Wednesday, March 9, 2005, at 04:38 PM, Jerry Hey wrote: Tracy, here is what I am hoping will happen. Heat will be pulled out of the exhaust gas by the additional skin area (187 sq inches) provided by the cool tube. This effect will be greatly magnified by the steady stream of high velocity cool air passing through the cool tube. As the exhaust gas looses temp, it also looses velocity. The exhaust pulses will weaken. Someone else, on the other list, calculated it would reduce inside muffler temps as much as 200 degrees. That is what I am hoping will happen. It is hard for me to believe the cool tube would have no or very slight effect. Bob White is going to instrument his exhaust so that we can get some real numbers. Regards, Jerry On Wednesday, March 9, 2005, at 04:00 PM, Tracy Crook wrote: = Verdana0000,0000,0000=A0 I may not be understanding what the 2 rotor version (cool pipe going all the way through) is supposed to accomplish or maybe my gut-feel thermodynamic instincts are way off.=A0 I can't imagine this would have any significant effect on exhaust temps, muffler wall temp or sound.=A0 =A0 Tracy=A0 (been wrong more than once) =A0 =A0 = Verdana0000,0000,0000Bill, from the picture you sent, it isn't clear to me where the 'cool tube' ends inside the muffler.=A0 Give me a = clue! =A0 Tracy Tracy, On the small muffler (2 rotor) the cool tube goes all the way thru. The front of the tube needs a feed from the cowl.=A0The exit needs a pipe=A0to the cowl exit although it could be very thin.=A0This is a sealed style like Jerry Hey and Ed Klepis have come up with. On the 3 rotor pipe the cool tube stops just inside the tailpipe. The section might be a little confusing as it shows a small support bar that was suggested to prevent the internal pipe from sagging. The sections I included should give a good indication. The intent is to form a annulus that should draw air through the tube venturi style. This needs only some clear space in front of the muffler. The idea is that you should mix air in the tailpipe to A; cool the exhaust and not burn the paint off the belly, and B; lessen the exhaust note by absorbing some of the exhaust energy by mixing cooler air with the exhaust. Bill Jepson =A0 = --Apple-Mail-2--1038620333--