Return-Path: Received: from [199.185.220.220] (HELO priv-edtnes56.telusplanet.net) by logan.com (CommuniGate Pro SMTP 4.2.9) with ESMTP id 710881 for flyrotary@lancaironline.net; Mon, 07 Feb 2005 02:39:28 -0500 Received-SPF: pass receiver=logan.com; client-ip=199.185.220.220; envelope-from=haywire@telus.net Received: from Endurance ([207.81.25.155]) by priv-edtnes56.telusplanet.net (InterMail vM.6.01.04.00 201-2131-118-20041027) with SMTP id <20050207073758.PLXE13203.priv-edtnes56.telusplanet.net@Endurance> for ; Mon, 7 Feb 2005 00:37:58 -0700 From: "Todd Bartrim" To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Re: Heating the Fuel Date: Sun, 6 Feb 2005 23:37:34 -0800 Message-ID: <001301c50ce7$e5bd8a30$0201a8c0@Endurance> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0014_01C50CA4.D79A4A30" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook CWS, Build 9.0.2416 (9.0.2910.0) Importance: Normal X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2180 In-Reply-To: This is a multi-part message in MIME format. ------=_NextPart_000_0014_01C50CA4.D79A4A30 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit [FlyRotary] Re: Performance coatings- bearing damage?Hi Dave; I considered this as well at one point, as a way to provide cooling and as possible way to prevent icing by having warmer fuel. I quickly dismissed this as first I'd rather just avoid icing at all costs and second this wouldn't have a constant effect as the tanks are drained. As you near to empty you would have much less volume of fuel to absorb the heat and it would be in contact with much less area of the wing skin to dissipate that heat to the air. I suspect that vapour lock would occur quickly. About the only time I could see any possibility for this is if you have a valve arrangement where you could select or bypass this cooling option. That would allow you to use that cooling during initial climbout when you have full tanks, but once at cruise altitude where you won't need the additional cooling you could bypass it, avoiding the possibility of vapour lock. This adds extra complexity and pilot workload and more possibilities for failure. Another slim possible failure mode would be coolant leaking into the fuel. Not likely in a well made heat exchanger, but it sure would ruin your day. I had a couple of vapour lock incidents that stopped the fan, two of which I was at high altitude and was able to restart, but one was in the circuit and resulted in a deadstick landing. I had all kinds of bypass valves and header vents, etc. back when I used a header tank, that I didn't think were too complex, but it sure was a pain to deal with when you're under pressure. I'm glad to be rid of them and all possibilities of vapour lock. If you're just looking to join the Deadstick Club so you can drink beer with us, I'm sure we can count your busted turbo, smoking oil, low power semi-emergency landing as admission to the club. Heck, I believe you had your wife on board when that happened? That's gotta add a whole new dimension of stress! :-) I think what George was referring to about the fuel cooling the rotors was the (new/old?) German Wankel which uses a charge air approach much like a 2-stroke engine where the incoming air/fuel mixture is drawn into the crankcase first to provide cooling & lubrication to the crankcase and gets precompressed by the piston down stroke as the port opens allowing the mixture to pass into the combustion chamber. This works well in that application, as the air/fuel mixture is already in a state of vapour and has no worries about vapour lock issues that stop fuel flow in fuel delivery systems. Those are my thoughts anyways... Todd ------=_NextPart_000_0014_01C50CA4.D79A4A30 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable [FlyRotary] Re: Performance coatings- bearing damage?
Hi=20 Dave;
    I considered this as well at one point, as a = way to provide=20 cooling and as possible way to prevent icing by having warmer fuel. I = quickly=20 dismissed this as first I'd rather just avoid icing at all costs and = second this=20 wouldn't have a constant effect as the tanks are drained. As you near to = empty=20 you would have much less volume of fuel to absorb the heat and it would = be in=20 contact with much less area of the wing skin to dissipate that heat to = the air.=20 I suspect that vapour lock would occur quickly.
    About the only time I could see any = possibility for=20 this is if you have a valve arrangement where you could select or bypass = this=20 cooling option. That would allow you to use that cooling during initial = climbout=20 when you have full tanks, but once at cruise altitude where you won't = need the=20 additional cooling you could bypass it, avoiding the possibility of = vapour lock.=20 This adds extra complexity and pilot workload and more possibilities for = failure. Another slim possible failure mode would be coolant leaking = into the=20 fuel. Not likely in a well made heat exchanger, but it sure would ruin = your=20 day.
    I had a couple of vapour lock incidents that = stopped the=20 fan, two of which I was at high altitude and was able to restart, but = one was in=20 the circuit and resulted in a deadstick landing. I had all kinds of = bypass=20 valves and header vents, etc. back when I used a header = tank, that I=20 didn't think were too complex, but it sure was a pain to deal with when = you're=20 under pressure. I'm glad to be rid of them and all possibilities of = vapour=20 lock.
    If you're just looking to join the Deadstick = Club so you=20 can drink beer with us, I'm sure we can count your busted turbo, smoking = oil,=20 low power semi-emergency landing as admission to the club. Heck, I = believe you=20 had your wife on board when that happened? That's gotta add a whole new=20 dimension of stress! :-)
 
    I think what George was referring to about the = fuel cooling=20 the rotors was the (new/old?) German Wankel which uses a charge air = approach=20 much like a 2-stroke engine where the incoming air/fuel mixture is drawn = into=20 the crankcase first to provide cooling & lubrication to the = crankcase and=20 gets precompressed by the piston down stroke as the port opens allowing = the=20 mixture to pass into the combustion chamber. This works well in that=20 application, as the air/fuel mixture is already in a state of vapour and = has no=20 worries about vapour lock issues that stop fuel flow in fuel delivery=20 systems.
 
Those=20 are my thoughts anyways...
 
Todd
 
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