Return-Path: Received: from [65.54.168.108] (HELO hotmail.com) by logan.com (CommuniGate Pro SMTP 4.3c1) with ESMTP id 724052 for flyrotary@lancaironline.net; Thu, 10 Feb 2005 14:24:07 -0500 Received-SPF: pass receiver=logan.com; client-ip=65.54.168.108; envelope-from=lors01@msn.com Received: from mail pickup service by hotmail.com with Microsoft SMTPSVC; Thu, 10 Feb 2005 11:22:00 -0800 Message-ID: Received: from 4.174.7.95 by BAY3-DAV4.phx.gbl with DAV; Thu, 10 Feb 2005 19:21:14 +0000 X-Originating-IP: [4.174.7.95] X-Originating-Email: [lors01@msn.com] X-Sender: lors01@msn.com From: "Tracy Crook" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Heating the Fuel Date: Thu, 10 Feb 2005 14:21:10 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0128_01C50F7B.C4C9A2F0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: MSN 9 X-MIMEOLE: Produced By MSN MimeOLE V9.10.0009.2900 Seal-Send-Time: Thu, 10 Feb 2005 14:21:10 -0500 X-OriginalArrivalTime: 10 Feb 2005 19:22:00.0792 (UTC) FILETIME=[CB7D1580:01C50FA5] This is a multi-part message in MIME format. ------=_NextPart_000_0128_01C50F7B.C4C9A2F0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable You have a good head Dave, your analysis is right on.=20 To amplify why vapor lock is not an issue here (assuming we get = adequate "tank cooling"), my plan was to cool the oil which gets to a = much higher temp than the coolant. I never got around to finding out = the boiling point of gasoline (anyone here know?) but it was my HOPE = that it would boil which would vastly increase the heat absorbed from = the oil. When the gasoline "steam" returned to the tank, it would = immediately cool and condense to it's liquid state, even if the tank was = almost empty. =20 Possible flaw is that some components of gasoline might be more volatile = than others, remain in vapor state and escape from the tank vent. =20 Tracy (still dreaming of drag free cooling) ----- Original Message -----=20 From: DaveLeonard=20 To: Rotary motors in aircraft=20 Sent: Thursday, February 10, 2005 1:13 AM Subject: [FlyRotary] Re: Heating the Fuel Bill & Jim, first and most important, we are all in agreement that = this is not worth doing. However, you made a couple of assumptions that are = not quiet accurate. First, the pumps from Tracy will return 40 gal/hr to = the tank (not 15 - I know, I monitor it in flight). Second, there will be = a much higher rise in the fuel temp. Because the fuel would be going so slowly through the heat exchanger I would EXPECT it to reach the = temperature of the incoming coolant, or about a 100 deg rise. This will not cause = "the mother of all vapor locks" becuase it will be headed back to the tank = where it will quickly be cooled. How quickly? Quickly enough that the temp = of the fuel on its way to the engine will be no warmer than ambient. It matters not the volume of fuel in the tank (other than contact area). = I expect it to be the temp of the fuel going TO the engine to be at = ambient - and adding no additional risk of vapor lock. But, the coolant will still only drop about 3 deg, which is not enough = to make it worth it. Dave Leonard > > <... For a 10 degree rise in gasoline temperature you would get a > 630/12000 =3D 0.0525 deg F drop in coolant temperature ...> > > OTOH, you'd soon heat your fuel to very near the coolant temp and = have > the mother of all vapor locks. > If that's what you're looking for ... Jim S. > > William wrote: > > > Dave, > > If you burn 10 g/hr, and are returning 15 g/hr to the tanks, that = is > > 15*6 =3D 90 #/hr of gasoline, with a specific heat of ~.7Btu/#, = that > > means you can transfer 90* 0.7 =3D 63 Btu/hr/degF rise in gasoline > > temperature. Your coolant flow is probably about 25 = gallons/minute, =3D > > 25*60 =3D 1500 gallons/hour =3D ~1500*8 =3D 12000 #/hour. For a 10 = degree > > rise in gasoline temperature you would get a 630/12000 =3D 0.0525 = deg F > > drop in coolant temperature. Doesn't seem worth it. > > > > * note: I used rounded figures for densities and flow rates and = heat > > capacities. The fact remains that the flow mismatch makes this not = do > > much. > > Bill Schertz > > KIS Cruiser # 4045 > > > > ----- Original Message ----- > > *From:* DaveLeonard = > > > *To:* Rotary motors in aircraft = > > > *Sent:* Sunday, February 06, 2005 11:46 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 > > > > >> Homepage: http://www.flyrotary.com/ > >> Archive: = http://lancaironline.net/lists/flyrotary/List.html >> Homepage: http://www.flyrotary.com/ >> Archive: = http://lancaironline.net/lists/flyrotary/List.html ------=_NextPart_000_0128_01C50F7B.C4C9A2F0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
You have a good head Dave, your analysis is right on. 
 
  To amplify why vapor lock is not an issue here (assuming we=20 get adequate "tank cooling"), my plan was to cool the oil which = gets to a=20 much higher temp than the coolant.   I never got around to = finding out=20 the boiling point of gasoline (anyone here know?) but it was my HOPE = that it=20 would boil which would vastly increase the heat absorbed from the = oil. =20 When the gasoline "steam" returned to the tank, it would immediately = cool and=20 condense to it's liquid state, even if the tank was almost empty.  =
 
Possible flaw is that some components of gasoline might be more = volatile=20 than others, remain in vapor state and escape from the tank vent.  =
 
Tracy (still dreaming of drag free cooling)
----- Original Message -----
To: Rotary motors in = aircraft
Sent: Thursday, February 10, = 2005 1:13=20 AM
Subject: [FlyRotary] Re: = Heating the=20 Fuel

Bill & Jim, first and most important, we are all in = agreement that this is
not worth doing.  However, you made a = couple of=20 assumptions that are not
quiet accurate.  First, the pumps = from Tracy=20 will return 40 gal/hr to the
tank (not 15 - I know, I monitor it in = flight).  Second, there will be a
much higher rise in the fuel = temp.  Because the fuel would be going so
slowly through the = heat=20 exchanger I would EXPECT it to reach the temperature
of the = incoming=20 coolant, or about a 100 deg rise.  This will not cause = "the
mother of=20 all vapor locks" becuase it will be headed back to the tank = where
it will=20 quickly be cooled.  How quickly?  Quickly enough that the = temp=20 of
the fuel on its way to the engine will be no warmer than = ambient. =20 It
matters not the volume of fuel in the tank (other than contact=20 area).      I
expect it to be the temp of = the fuel=20 going TO the engine to be at ambient -
and adding no additional = risk of=20 vapor lock.

But, the coolant will still only drop about 3 deg, = which is=20 not enough to
make it worth it.

Dave = Leonard


>
>=20 <... For a 10 degree rise in gasoline temperature you would get = a
>=20 630/12000 =3D 0.0525 deg F drop in coolant temperature = ..>
>
>=20 OTOH, you'd soon heat your fuel to very near the coolant temp and = have
>=20 the mother of all vapor locks.
> If that's what you're looking = for ...=20 Jim S.
>
> William wrote:
>
> > = Dave,
> >=20 If you burn 10 g/hr, and are returning 15 g/hr to the tanks, that = is
>=20 > 15*6 =3D 90 #/hr of gasoline, with a specific heat of ~.7Btu/#,=20 that
> > means you can transfer 90* 0.7 =3D 63 Btu/hr/degF = rise in=20 gasoline
> > temperature. Your coolant flow is probably about = 25=20 gallons/minute, =3D
> > 25*60 =3D 1500 gallons/hour =3D = ~1500*8 =3D 12000=20 #/hour. For a 10 degree
> > rise in gasoline temperature you = would=20 get a 630/12000 =3D 0.0525 deg F
> > drop in coolant = temperature. =20 Doesn't seem worth it.
> >
> > * note: I used = rounded=20 figures for densities and flow rates and heat
> > capacities. = The=20 fact remains that the flow mismatch makes this not do
> >=20 much.
> > Bill Schertz
> > KIS Cruiser # = 4045
>=20 >
> >     ----- Original Message = -----
>=20 >     *From:* DaveLeonard <mailto:daveleonard@cox.net>>=20 >     *To:* Rotary motors in aircraft <mailto:flyrotary@lancaironlin= e.net>
>=20 >     *Sent:* Sunday, February 06, 2005 11:46=20 PM
> >     *Subject:* [FlyRotary] Heating = the=20 Fuel
> >
> >     In anticipation = of the=20 new turbo, I am considering ways to improve
>=20 >     coolant cooling.  Besides the = obvious more=20 air, more ducting, more
> >     radiator; = I have=20 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=20 fuel instead of oil.  I would
> = >     use=20 the fuel on the way back to the tank, and the coolant after it
> = >     has already been cooled by the = radiator. =20 The fuel would then go
> >     back to = the nice=20 metal tank of the RV.
> >
> = >     I am=20 looking for input on the implications of heating the fuel.  = I
>=20 >     expect it would reach max temps of about = 190=20 (usually a
> >     little cooler) but = quickly=20 cool once in the tank.  Can the fuel
> = >    =20 tolerate that temp without vaporizing?  It will probably expand=20 in
> >     the tank but I don't expect = that will=20 occur faster than it is used
> >     = up.  I=20 have no guess as to what temp will become steady state for
>=20 >     the fuel pumped out of the tank.  My = guess=20 is that it will not be
> >     much = warmer than=20 normal, but a slight increase in temp may help
>=20 >     with vaporization.
> >
>=20 >     The last question is how much will it = cool the=20 coolant.  My hope
> >     is about = 10 deg=20 but I doubt it will be quite that much.  I know
>=20 >     others have considered using the fuel to = cool=20 (Tracy) and I would
> >     appreciate = your=20 thoughts.
> >
> >     Dave=20 Leonard
> >
>
> >>  Homepage:  http://www.flyrotary.com/
> = >>  Archive:   http://lancai= ronline.net/lists/flyrotary/List.html


>> =20 Homepage:  http://www.flyrotary.com/
>&= gt; =20 Archive:   http://lancai= ronline.net/lists/flyrotary/List.html
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