Return-Path: Received: from email2k3.itlnet.net ([64.19.112.12] verified) by logan.com (CommuniGate Pro SMTP 4.3c1) with ESMTP id 724273 for flyrotary@lancaironline.net; Thu, 10 Feb 2005 17:18:19 -0500 Received-SPF: none receiver=logan.com; client-ip=64.19.112.12; envelope-from=jwvoto@itlnet.net Received: from rav.itlnet.net (unverified [192.168.10.149]) by itlnet.net (Rockliffe SMTPRA 6.1.17) with SMTP id for ; Thu, 10 Feb 2005 16:17:35 -0600 Received: from JWVOTO (unverified [64.19.116.115]) by itlnet.net (Rockliffe SMTPRA 6.1.17) with SMTP id for ; Thu, 10 Feb 2005 16:17:33 -0600 Message-ID: <00a001c50fbe$c259e000$73741340@JWVOTO> From: "Wendell Voto" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Heating the Fuel Date: Thu, 10 Feb 2005 16:20:05 -0600 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_009D_01C50F8C.616D0560" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 5.50.4133.2400 X-MimeOLE: Produced By Microsoft MimeOLE V5.50.4133.2400 This is a multi-part message in MIME format. ------=_NextPart_000_009D_01C50F8C.616D0560 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Boiling the fuel? Isn't this the same as trying to re-refine the = gasoline? I think this would cause all sorts of stuff to be distilled = out and clog the fuel line. My $.02 Wendell 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_009D_01C50F8C.616D0560 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
 
Boiling the fuel? Isn't this the same as trying to re-refine = the=20 gasoline? I think this would cause all sorts of stuff to be distilled = out and=20 clog the fuel line. My $.02
Wendell
 
  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=20 out the boiling point of gasoline (anyone here know?) but it was my = HOPE that=20 it would boil which would vastly increase the heat absorbed from the=20 oil.  When the gasoline "steam" returned to the tank, it would=20 immediately cool and condense to it's liquid state, even if the tank = was=20 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 -----
From: DaveLeonard
To: Rotary motors in = aircraft=20
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=20 agreement that this is
not worth doing.  However, you made a = couple=20 of assumptions that are not
quiet accurate.  First, the = pumps from=20 Tracy will return 40 gal/hr to the
tank (not 15 - I know, I = monitor it in=20 flight).  Second, there will be a
much higher rise in the = fuel=20 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=20 of all vapor locks" becuase it will be headed back to the tank = where
it=20 will quickly be cooled.  How quickly?  Quickly enough that = the=20 temp of
the fuel on its way to the engine will be no warmer than=20 ambient.  It
matters not the volume of fuel in the tank = (other than=20 contact area).      I
expect it to be = the temp=20 of the fuel going TO the engine to be at ambient -
and adding no=20 additional risk of vapor lock.

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

Dave = Leonard


>
> <... For a 10 degree rise in = gasoline=20 temperature you would get a
> 630/12000 =3D 0.0525 deg F drop = in coolant=20 temperature ..>
>
> OTOH, you'd soon heat your fuel = to very=20 near the coolant temp and have
> the mother of all vapor=20 locks.
> If that's what you're looking for ... Jim = S.
>
>=20 William wrote:
>
> > Dave,
> > If you burn = 10 g/hr,=20 and are returning 15 g/hr to the tanks, that is
> > 15*6 = =3D 90 #/hr=20 of gasoline, with a specific heat of ~.7Btu/#, that
> > = means you=20 can transfer 90* 0.7 =3D 63 Btu/hr/degF rise in gasoline
> = >=20 temperature. Your coolant flow is probably about 25 gallons/minute,=20 =3D
> > 25*60 =3D 1500 gallons/hour =3D ~1500*8 =3D 12000 = #/hour. For a 10=20 degree
> > rise in gasoline temperature you would get a = 630/12000 =3D=20 0.0525 deg F
> > drop in coolant temperature.  Doesn't = seem=20 worth it.
> >
> > * note: I used rounded figures = for=20 densities and flow rates and heat
> > capacities. The fact = remains=20 that the flow mismatch makes this not do
> > much.
> = >=20 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 = PM
> >     *Subject:* [FlyRotary] = Heating the=20 Fuel
> >
> >     In = anticipation of=20 the new turbo, I am considering ways to improve
>=20 >     coolant cooling.  Besides the = obvious more=20 air, more ducting, more
> >     = radiator; I=20 have been again toying with the idea of a heat
>=20 >     exchanger.  This time coolant to=20 fuel.  The plan would be to use a
> = >    =20 typical oil/water exchanger but use fuel instead of oil.  I=20 would
> >     use the fuel on the way = back to=20 the tank, and the coolant after it
> = >     has=20 already been cooled by the radiator.  The fuel would then = go
>=20 >     back to the nice metal tank of the = RV.
>=20 >
> >     I am looking for input on = the=20 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=20 will probably expand in
> >     the = tank but I=20 don't expect that will occur faster than it is used
>=20 >     up.  I have no guess as to what = temp will=20 become steady state for
> >     the = fuel pumped=20 out of the tank.  My guess is that it will not be
>=20 >     much warmer than normal, but a slight = increase=20 in temp may help
> >     with=20 vaporization.
> >
> >     The = last=20 question is how much will it cool the coolant.  My hope
> = >     is about 10 deg but I doubt it will be = quite=20 that much.  I know
> >     others = have=20 considered using the fuel to cool (Tracy) and I would
>=20 >     appreciate your thoughts.
> = >
>=20 >     Dave Leonard
> = >
>
>=20 >>  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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