X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from cdptpa-omtalb.mail.rr.com ([75.180.132.120] verified) by logan.com (CommuniGate Pro SMTP 5.2.2) with ESMTP id 2892898 for flyrotary@lancaironline.net; Sun, 04 May 2008 09:50:54 -0400 Received-SPF: pass receiver=logan.com; client-ip=75.180.132.120; envelope-from=eanderson@carolina.rr.com Received: from edward2 ([75.191.186.236]) by cdptpa-omta06.mail.rr.com with SMTP id <20080504135015.OWVP20708.cdptpa-omta06.mail.rr.com@edward2> for ; Sun, 4 May 2008 13:50:15 +0000 Message-ID: <001a01c8aded$cdf3a3d0$2402a8c0@edward2> From: "Ed Anderson" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Jet-A Date: Sun, 4 May 2008 09:50:24 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0017_01C8ADCC.469F5580" 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_0017_01C8ADCC.469F5580 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable 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. ------=_NextPart_000_0017_01C8ADCC.469F5580 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
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 = initial=20 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.   So=20 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 figures=20 for Jet A as low as 0.1 psi can be found whereas it appears to =  vary=20 from 9 - 14.7 psi for automobile gasoline (these figures are apparently = mandate=20 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=20 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 = piston=20 engine nor the ordinary rotary would have much success in running on 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 = Steitle=20
Sent: Sunday, May 04, 2008 7:31 = 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.
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