Return-Path: Received: from mail10.syd.optusnet.com.au ([211.29.132.191] verified) by logan.com (CommuniGate Pro SMTP 4.2.9) with ESMTP-TLS id 710859 for flyrotary@lancaironline.net; Mon, 07 Feb 2005 01:45:19 -0500 Received-SPF: none receiver=logan.com; client-ip=211.29.132.191; envelope-from=lendich@optusnet.com.au Received: from george (d211-29-160-204.dsl.nsw.optusnet.com.au [211.29.160.204]) by mail10.syd.optusnet.com.au (8.12.11/8.12.11) with SMTP id j176hgT0016945 for ; Mon, 7 Feb 2005 17:43:43 +1100 Message-ID: <000d01c50ce0$a9fc50a0$cca01dd3@george> From: "George Lendich" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Heating the Fuel Date: Mon, 7 Feb 2005 16:45:50 +1000 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_000A_01C50D34.7B35A1A0" 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 This is a multi-part message in MIME format. ------=_NextPart_000_000A_01C50D34.7B35A1A0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable [FlyRotary] Re: Performance coatings- bearing damage? Dave, The NSU and their derivatives do use fuel to cool the rotors, so I'm led = to believe. George (down under) 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.=20 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=20 To: Rotary motors in aircraft=20 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_000A_01C50D34.7B35A1A0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable [FlyRotary] Re: Performance coatings- bearing = damage?
 
Dave,
The NSU and their derivatives do use = fuel to cool=20 the rotors, so I'm led to believe.
George (down under)

George, I would not be = returning the=20 heated fuel to a header tank, but to the main wing tank where it could = be=20 quickly cooled by the airflow.
 
I'm not=20 sure what you mean by fuel cooling the rotors, oil cools the = rotors the=20 Mazda 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=20 causes 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=20 the rotors is suspect in this regard. I have no facts on this, only = what has=20 been 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 anticipation of the new turbo, I am considering ways = to improve=20 coolant cooling.  Besides the obvious more air, more ducting, = more=20 radiator; I have been again toying with the idea of a heat=20 exchanger.  This time coolant to fuel.  The plan would = be to use=20 a typical oil/water exchanger but use fuel instead of oil.  I = would=20 use the fuel on the way back to the tank, and the coolant after it = has=20 already been cooled by the radiator.  The fuel would then go = back to=20 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=20 little cooler) but quickly cool once in the tank.  = Can the=20 fuel tolerate that temp without vaporizing?  It will probably = expand=20 in the tank but I don't expect that will occur faster than it is = used=20 up.  I have no guess as to what temp will become steady state = for the=20 fuel pumped out of the tank.  My guess is that it will not be = much=20 warmer than normal, but a slight increase in temp may help with=20 vaporization.
 
The last question is how much will it cool the = coolant.  My=20 hope is about 10 deg but I doubt it will be quite that much.  = I know=20 others have considered using the fuel to cool (Tracy) and I would=20 appreciate your thoughts.
 
Dave=20 Leonard
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