Return-Path: Sender: (Marvin Kaye) To: flyrotary Date: Sun, 01 Dec 2002 15:53:56 -0500 Message-ID: X-Original-Return-Path: Received: from mtiwmhc13.worldnet.att.net ([204.127.131.117] verified) by logan.com (CommuniGate Pro SMTP 4.0.2) with ESMTP id 1892132 for flyrotary@lancaironline.net; Sun, 01 Dec 2002 13:05:05 -0500 Received: from computer ([12.84.206.30]) by mtiwmhc13.worldnet.att.net (InterMail vM.5.01.05.12 201-253-122-126-112-20020820) with SMTP id <20021201180502.GGEM24110.mtiwmhc13.worldnet.att.net@computer> for ; Sun, 1 Dec 2002 18:05:02 +0000 X-Original-Message-ID: <004401c29964$2f632040$1ece540c@computer> Reply-To: "Tom Kendall" From: "Tom Kendall" X-Original-To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Coolant loss : More cooling system test stuff. X-Original-Date: Sun, 1 Dec 2002 11:54:48 -0600 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_003C_01C29930.731AA080" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2600.0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2600.0000 This is a multi-part message in MIME format. ------=_NextPart_000_003C_01C29930.731AA080 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Well, not quite. Visualizing thermal expansion is something that gives = everybody headaches. Simply put: on the inside everything gets farther = apart just like on the outside. So the volume of the cavity for the = coolant actually gets larger. Think of it this way: you are sitting on the edge of a hole drilled in = a plate. As the plate heats up, the metal starts expanding away from = you in all directions. The far side of the hole expands away from you = too. But the thermal expansion coefficient for liquids is inevitably much = greater than for metals. So much so, that any change in the volume of = the tank (or engine cavity) is trivial in comparison. The liquid = expansion dominates. Tom Kendall ----- Original Message -----=20 From: Al Gietzen=20 To: Rotary motors in aircraft=20 Sent: Sunday, December 01, 2002 1:04 AM Subject: [FlyRotary] Re: Coolant loss : More cooling system test = stuff. Another factor that affects the coolant volume is the expansion of the = metal in the engine. The coolant is essentially contained in an annular = region around the rotors. The inside of that annulus gets pretty hot. = Could be that the coolant capacity in the engine is decreased. =20 I have no idea how big a factor this is, but it seems that that = overall coolant "expansion" is more in a rotary. I'd estimate that the = amount of coolant that gets pushed into the catch bottle on the V-8 in = my van is a pint or less. Al .Tracy and others, what is the theory behind so much liquid in the = external expansion tank? Thermal expansion of the initial coolant volume = doesn't account for such a large overflow. So is vapor building up inside? = If it is there is no longer a liquid filled system. I don't get it. Peter >> Homepage: http://www.flyrotary.com/ ------=_NextPart_000_003C_01C29930.731AA080 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Well, not quite.  Visualizing thermal expansion is something = that=20 gives everybody headaches.  Simply put: on the inside everything = gets=20 farther apart just like on the outside.  So the volume of the = cavity for=20 the coolant actually gets larger.
 
Think of it this way:  you are sitting on the edge of a hole = drilled=20 in a plate.  As the plate heats up, the metal starts expanding away = from=20 you in all directions.  The far side of the hole expands away from = you=20 too.
 
But the thermal expansion coefficient for liquids is inevitably = much=20 greater than for metals.  So much so, that any change in the volume = of the=20 tank (or engine cavity) is trivial in comparison.  The liquid = expansion=20 dominates.
 
Tom Kendall
----- Original Message -----
From:=20 Al=20 Gietzen
Sent: Sunday, December 01, 2002 = 1:04=20 AM
Subject: [FlyRotary] Re: = Coolant loss :=20 More cooling system test stuff.

Another factor that affects the coolant = volume is the=20 expansion of the metal in the engine.  The coolant is essentially = contained in an annular region around the rotors.  The inside of = that=20 annulus gets pretty hot.  Could be that the coolant capacity = in the=20 engine is decreased. 
 
I have no idea how big a factor this is, but = it seems=20 that that overall coolant "expansion" is more in a rotary.  I'd = estimate=20 that the amount of coolant that gets pushed into the catch bottle on = the V-8=20 in my van is a pint or less.
 
Al

.Tracy=20 and others, what is the theory behind so much liquid in the=20 external
expansion tank? Thermal expansion of the initial coolant = volume=20 doesn't
account for such a large overflow. So is vapor building = up=20 inside? If it is
there is no longer a liquid filled system. I = don't get=20 it.
Peter


>>  Homepage:  http://www.flyrotary.com/

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