Return-Path: Received: from fed1rmmtao02.cox.net ([68.230.241.37] verified) by logan.com (CommuniGate Pro SMTP 4.2.9) with ESMTP id 710858 for flyrotary@lancaironline.net; Mon, 07 Feb 2005 01:17:15 -0500 Received-SPF: none receiver=logan.com; client-ip=68.230.241.37; envelope-from=daveleonard@cox.net Received: from davidandanne ([68.101.147.215]) by fed1rmmtao02.cox.net (InterMail vM.6.01.04.00 201-2131-117-20041022) with SMTP id <20050207061542.GZUW9332.fed1rmmtao02.cox.net@davidandanne> for ; Mon, 7 Feb 2005 01:15:42 -0500 From: "DaveLeonard" To: "Rotary motors in aircraft" Subject: RE: [FlyRotary] Re: Heating the Fuel Date: Sun, 6 Feb 2005 22:15:45 -0800 Message-ID: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_002B_01C50C99.67B79020" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook IMO, Build 9.0.2416 (9.0.2910.0) X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2180 In-Reply-To: Importance: Normal This is a multi-part message in MIME format. ------=_NextPart_000_002B_01C50C99.67B79020 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit [FlyRotary] Re: Performance coatings- bearing damage?George, I would not be returning the heated fuel to a header tank, but to the main wing tank where it could be quickly cooled by the airflow. I'm not sure what you mean by fuel cooling the rotors, oil cools the rotors the Mazda Wankel. Dave, In current return systems, returning the fuel from the fuel rail alone to a header tank is a NO! NO! The residual heat in a small fuel tank isn't sufficient to cool the fuel before it goes back into the fuel rail - it causes vapour lock. All return fuel, I have been told , must return to the much larger tanks to dissipate the heat The Wankel Rotary which has fuel cooling the rotors is suspect in this regard. I have no facts on this, only what has been discussed on other sites. Given this information I believe you may have a considerable problem with heat. George ( down under) From: DaveLeonard To: Rotary motors in aircraft Sent: Monday, February 07, 2005 3:46 PM Subject: [FlyRotary] Heating the Fuel In anticipation of the new turbo, I am considering ways to improve coolant cooling. Besides the obvious more air, more ducting, more radiator; I have been again toying with the idea of a heat exchanger. This time coolant to fuel. The plan would be to use a typical oil/water exchanger but use fuel instead of oil. I would use the fuel on the way back to the tank, and the coolant after it has already been cooled by the radiator. The fuel would then go back to the nice metal tank of the RV. I am looking for input on the implications of heating the fuel. I expect it would reach max temps of about 190 (usually a little cooler) but quickly cool once in the tank. Can the fuel tolerate that temp without vaporizing? It will probably expand in the tank but I don't expect that will occur faster than it is used up. I have no guess as to what temp will become steady state for the fuel pumped out of the tank. My guess is that it will not be much warmer than normal, but a slight increase in temp may help with vaporization. The last question is how much will it cool the coolant. My hope is about 10 deg but I doubt it will be quite that much. I know others have considered using the fuel to cool (Tracy) and I would appreciate your thoughts. Dave Leonard ------=_NextPart_000_002B_01C50C99.67B79020 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable [FlyRotary] Re: Performance coatings- bearing = damage?
George, I would not be returning the heated = fuel to a=20 header tank, but to the main wing tank where it could be quickly cooled = by the=20 airflow.
 
I'm not sure=20 what you mean by fuel cooling the rotors, oil cools the rotors the = Mazda=20 Wankel. 

Dave,
In current return systems, returning = the fuel=20 from the fuel rail alone to a header tank is a NO! NO!
The residual heat in a small fuel = tank isn't=20 sufficient to cool the fuel before it goes back into the fuel rail - = it causes=20 vapour lock.
All return fuel, I have been told , = must return=20 to the much larger tanks to dissipate the heat
 
The Wankel Rotary which has fuel = cooling the=20 rotors is suspect in this regard. I have no facts on this, only what = has been=20 discussed on other sites.
 
Given this information I believe you = may have a=20 considerable problem with heat.
 
George ( down under)
From:=20 DaveLeonard
To: Rotary motors in = aircraft=20
Sent: Monday, February 07, = 2005 3:46=20 PM
Subject: [FlyRotary] Heating = the=20 Fuel

In=20 anticipation of the new turbo, I am considering ways to improve = coolant=20 cooling.  Besides the obvious more air, more ducting, more = radiator; I=20 have been again toying with the idea of a heat exchanger.  This = time=20 coolant to fuel.  The plan would be to use a typical oil/water=20 exchanger but use fuel instead of oil.  I would use the fuel on = the way=20 back to the tank, and the coolant after it has already been cooled = by the=20 radiator.  The fuel would then go back to the nice metal tank = of the=20 RV.
 
I=20 am looking for input on the implications of heating the fuel.  = I expect=20 it would reach max temps of about 190 (usually a=20 little cooler) but quickly cool once in the tank.  = Can the=20 fuel tolerate that temp without vaporizing?  It will probably = expand in=20 the tank but I don't expect that will occur faster than it is used = up. =20 I have no guess as to what temp will become steady state for the = fuel pumped=20 out of the tank.  My guess is that it will not be much warmer = than=20 normal, but a slight increase in temp may help with=20 vaporization.
 
The last question is how much will it cool the = coolant.  My hope=20 is about 10 deg but I doubt it will be quite that much.  I know = others=20 have considered using the fuel to cool (Tracy) and I would = appreciate your=20 thoughts.
 
Dave = Leonard
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