X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from smtp1.av-mx.com ([137.118.16.57] verified) by logan.com (CommuniGate Pro SMTP 5.2.2) with ESMTP id 2892980 for flyrotary@lancaironline.net; Sun, 04 May 2008 11:48:59 -0400 Received-SPF: pass receiver=logan.com; client-ip=137.118.16.57; envelope-from=res12@fairpoint.net Received: from main (dflo-67-158-146-116.gtcom.net [67.158.146.116]) (Authenticated sender: res12@fairpoint.net) by smtp1.av-mx.com (Postfix) with ESMTP id A609C2906A7 for ; Sun, 4 May 2008 11:48:19 -0400 (EDT) Message-ID: <002701c8adfe$514a4760$0202a8c0@main> From: "Richard Sohn" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Jet-A Date: Sun, 4 May 2008 10:48:35 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0024_01C8ADD4.66E86F40" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.3138 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3198 This is a multi-part message in MIME format. ------=_NextPart_000_0024_01C8ADD4.66E86F40 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Ed, what you described is exactly why it is so hard to come up with a good = working, spark ignition, heavy fuel(diesel/JP) engine. It seems that in = order to solving this problem one would have to beat basic physics. The real diesel only works because most of the fuel droplets combust at = the same time, eliminating the influence of flame propagation velocity. FW Richard Sohn N2071U ----- Original Message -----=20 From: Ed Anderson=20 To: Rotary motors in aircraft=20 Sent: Sunday, May 04, 2008 8:50 AM Subject: [FlyRotary] Re: Jet-A Thanks for the vote of confidence(I think), Mark. =20 I don't know, but I suspect there would be a problem with Jet A in the = typical rotary as well. Here is my very initial take on what the major = problem "Might" be trying to run on Jet A. The flash point of gasoline is nominally around - 45F whereas the = flashpoint of Jet A fuel ranges from 102 - 104F. So more energy is = required to ignite it even if the fuel mixture is in a "combustible" = state. The Reid vapor point of JP fuels vary but figures for Jet A as low as = 0.1 psi can be found whereas it appears to vary from 9 - 14.7 psi for = automobile gasoline (these figures are apparently mandate by various = federal and state requirements) . The vapor point basically relates to = how easily the fuel will turn into a vapor which is required for = ignition. The higher the vapor point the more easily converted to vapor = - is my understanding. To ignite and permit propagation of the flame front each fuel type = vapor content must fall between a minimum and upper limit of = concentration as a mixture. For example this mixture for gasoline is = between 1% (min) and 6% (maximum), but it varies for different fuels. = Naturally, our fuel system is designed to meet the mixture limits for = gasoline. So My best guess is that give the higher flash point required, given = the much lower volatility (lower vapor pressure) and the different = mixture limits of Jet A is that neither a ordinary piston engine nor = the ordinary rotary would have much success in running on Jet A.. =20 However, I am not a fuel/combustion chemist nor did I sleep at a = Holiday Inn last night. Ed Ed Anderson Rv-6A N494BW Rotary Powered Matthews, NC eanderson@carolina.rr.com http://www.andersonee.com http://members.cox.net/rogersda/rotary/configs.htm#N494BW http://www.dmack.net/mazda/index.html ----- Original Message -----=20 From: Mark Steitle=20 To: Rotary motors in aircraft=20 Sent: Sunday, May 04, 2008 7:31 AM Subject: [FlyRotary] Jet-A OK, here's a question out of left field. A Lancair recently went = down in AZ right after being refueled. On the Lancair list, the = speculation is that it was fueled with Jet-A. I was curious, if this = happened to a rotary, would it run (continue to produce power) on jet-a = or would the engine quit? I speculate that due to the fuel pumps = continuously circulating the fuel to the fuel rails and back to the = tank, it probably wouldn't even start, but if it did, would it continue = to run on the mix of jet-a and mogas? I guess it depends on the ratio = of mogas to jet-a. Assuming that the fuel was almost 100% jet-A, would = it still run? =20 Ed, you've pretty much had everything happen to you that can = possibly happen in an airplane, what-you-say? =20 Mark S. -------------------------------------------------------------------------= ----- No virus found in this incoming message. Checked by AVG.=20 Version: 7.5.524 / Virus Database: 269.23.8/1413 - Release Date: = 5/3/2008 11:22 AM ------=_NextPart_000_0024_01C8ADD4.66E86F40 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Ed,
 
what you described is exactly why it is = so hard to=20 come up with a good working, spark ignition, heavy fuel(diesel/JP) = engine. It=20 seems that in order to solving this problem one would have to beat = basic=20 physics.
 
The real diesel only works because most = of the fuel=20 droplets combust at the same time, eliminating the influence of flame=20 propagation velocity.
 
FW
 
Richard Sohn
N2071U
 
----- Original Message -----
From:=20 Ed=20 Anderson
Sent: Sunday, May 04, 2008 8:50 = AM
Subject: [FlyRotary] Re: = Jet-A

Thanks for the vote of confidence(I = think),=20 Mark. 
 
I don't know, but I suspect there = would be a=20 problem with Jet A in the typical rotary as well.  Here is my = very=20 initial take on what the major problem "Might" be trying to run on Jet = A.
 
The flash point of gasoline is = nominally around=20 - 45F whereas the flashpoint of Jet A fuel ranges from 102 - = 104F.  =20 So more energy is required to ignite it even if the fuel mixture is in = a=20 "combustible" state.
 
The Reid vapor point of JP fuels vary = but=20 figures for Jet A as low as 0.1 psi can be found whereas = it appears to=20  vary from 9 - 14.7 psi for automobile gasoline (these figures = are=20 apparently mandate by various federal and state requirements) = .  =20 The vapor point basically relates to how easily the fuel will turn = into a=20 vapor which is required for ignition.  The higher the vapor point = the=20 more easily converted to vapor - is my = understanding.
 
To ignite and permit propagation of = the flame=20 front each fuel type vapor content must fall between a minimum and = upper limit=20 of concentration as a mixture.  For example this mixture for = gasoline is=20 between 1% (min) and 6% (maximum), but it varies for different = fuels. =20 Naturally, our fuel system is designed to meet the mixture limits for=20 gasoline.
 
So My best guess is that give the = higher flash=20 point required, given the much lower volatility (lower vapor pressure) = and the=20 different mixture limits  of Jet A  is that neither a = ordinary=20 piston engine nor the ordinary rotary would have much success in = running on=20 Jet A.. 
 
However, I am not a fuel/combustion = chemist nor=20 did I sleep at a Holiday Inn last night.
 
Ed
 
Ed Anderson
Rv-6A N494BW Rotary=20 Powered
Matthews, NC
eanderson@carolina.rr.comhttp://www.andersonee.com
http:/= /members.cox.net/rogersda/rotary/configs.htm#N494BW
http://www.dmack.net/mazda= /index.html
 
 
 
 
----- Original Message -----
From:=20 Mark=20 Steitle
To: Rotary motors in = aircraft=20
Sent: Sunday, May 04, 2008 = 7:31=20 AM
Subject: [FlyRotary] = Jet-A

OK, here's a question out of left field.  A = Lancair=20 recently went down in AZ right after being refueled.  On the = Lancair=20 list, the speculation is that it was fueled with Jet-A.  I was = curious,=20 if this happened to a rotary, would it run (continue to produce = power) on=20 jet-a or would the engine quit?  I speculate that due to the = fuel pumps=20 continuously circulating the fuel to the fuel rails and back to the = tank, it=20 probably wouldn't even start, but if it did, would it continue to = run on the=20 mix of jet-a and mogas?   I guess it depends on the ratio = of mogas=20 to jet-a.  Assuming that the fuel was almost 100% jet-A, would = it still=20 run? 

Ed, you've pretty much had everything happen to = you that=20 can possibly happen in an airplane, what-you-say?  =


Mark=20 S.

No virus found in this incoming message.
Checked by AVG.=20
Version: 7.5.524 / Virus Database: 269.23.8/1413 - Release Date: = 5/3/2008=20 11:22 AM
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