X-Virus-Scanned: clean according to Sophos on Logan.com From: "Steven W. Boese" Received: from [104.47.36.127] (HELO NAM02-SN1-obe.outbound.protection.outlook.com) by logan.com (CommuniGate Pro SMTP 6.2c1) with ESMTPS id 9597605 for flyrotary@lancaironline.net; Wed, 22 Mar 2017 13:57:23 -0400 Received-SPF: none receiver=logan.com; client-ip=104.47.36.127; envelope-from=SBoese@uwyo.edu DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=uwy.onmicrosoft.com; s=selector1-uwyo-edu; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version; bh=Cxc8JHO1WEVi+HLYGcQvKm8sNxrn4umWj9DHzGPYAd4=; b=U8ei3cBEaTb8tGpn1DCClcszZJoU76D0xm7O04PO+3EwZeNACpsDSNwhf/vzuhU5gQQiIEG8GNK/uwsfU4n0yS5J7igSNqm4LdkeJeJzLPmgKzVlCB//TNlAPSM+b16zI12D0Rc2Ibot9+QYLr/j2DWR7pRFqUL0AKsHmWmCqOE= Received: from CO2PR0501MB903.namprd05.prod.outlook.com (10.141.247.18) by CO2PR0501MB901.namprd05.prod.outlook.com (10.141.247.16) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.991.4; Wed, 22 Mar 2017 17:57:04 +0000 Received: from CO2PR0501MB903.namprd05.prod.outlook.com ([10.141.247.18]) by CO2PR0501MB903.namprd05.prod.outlook.com ([10.141.247.18]) with mapi id 15.01.0991.013; Wed, 22 Mar 2017 17:57:04 +0000 To: Rotary motors in aircraft Subject: Re: [FlyRotary] Re: fuel system peer review Thread-Topic: [FlyRotary] Re: fuel system peer review Thread-Index: AQHSowjiG6eRUJxAz0ihK0hEXhmZ2KGhGM1r Date: Wed, 22 Mar 2017 17:57:03 +0000 Message-ID: References: In-Reply-To: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: authentication-results: lancaironline.net; dkim=none (message not signed) header.d=none;lancaironline.net; dmarc=none action=none header.from=uwyo.edu; x-originating-ip: [69.146.90.23] x-microsoft-exchange-diagnostics: 1;CO2PR0501MB901;7:ks3iUmv/eMXBHGLE92fayo0y6O9PbQYEY9LhRmGlMP7BbFrJ+ERV/P/chEPmyrECuPz05J6r1pC++xWXErGrM11O3A/UOYOzwBKSTfa1pb3LffezeKEKRiRtQNcO0oMz+PiLcgbXXG4dhGfBNiDSl8CCsHlhP3Y/Xv5Jr+jbIt8cq6EKcYfQFGet1qFNhuF3tanBHIEC6xSZdkgM2z7vFiO7s2RtFtmLzfQTJaa9Jg26doEPwNWsW9mrqDK/u54I6HLWH/eVsIMXKR1Pcl6J9OAhxov5bJVvlBmkKESpXvNE3PYTZmqkNm8uT6fB4Xt4V90YrT7QRt6I7e8FQV4+5A== x-ms-office365-filtering-correlation-id: 9f74bdf3-37a7-4923-cf37-08d4714cd921 x-microsoft-antispam: UriScan:;BCL:0;PCL:0;RULEID:(22001)(2017030254075);SRVR:CO2PR0501MB901; x-microsoft-antispam-prvs: x-exchange-antispam-report-test: UriScan:; x-exchange-antispam-report-cfa-test: BCL:0;PCL:0;RULEID:(6040375)(601004)(2401047)(8121501046)(5005006)(3002001)(10201501046)(6041248)(20161123560025)(20161123558025)(20161123562025)(20161123564025)(20161123555025)(6072148);SRVR:CO2PR0501MB901;BCL:0;PCL:0;RULEID:;SRVR:CO2PR0501MB901; x-forefront-prvs: 02543CD7CD x-forefront-antispam-report: SFV:NSPM;SFS:(10019020)(39450400003)(279900001)(24454002)(66654002)(377454003)(8936002)(33656002)(19627405001)(54356999)(76176999)(50986999)(66066001)(122556002)(74316002)(77096006)(8676002)(25786009)(75432002)(81166006)(6506006)(189998001)(86362001)(19625305001)(229853002)(54896002)(7906003)(6116002)(9686003)(3846002)(102836003)(80792005)(5660300001)(2950100002)(7696004)(6916009)(7736002)(606005)(6436002)(55016002)(6246003)(5890100001)(38730400002)(3660700001)(88552002)(3280700002)(53936002)(6306002)(110136004)(2906002)(236005)(53546009)(966004)(99286003);DIR:OUT;SFP:1102;SCL:1;SRVR:CO2PR0501MB901;H:CO2PR0501MB903.namprd05.prod.outlook.com;FPR:;SPF:None;MLV:sfv;LANG:en; spamdiagnosticoutput: 1:99 spamdiagnosticmetadata: NSPM Content-Type: multipart/alternative; boundary="_000_CO2PR0501MB9033E2DE3D5FE30B32EBB08B93C0CO2PR0501MB903na_" MIME-Version: 1.0 X-OriginatorOrg: uwyo.edu X-MS-Exchange-CrossTenant-originalarrivaltime: 22 Mar 2017 17:57:03.9469 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-id: f9cdd7ad-825d-4601-8e9c-a325e02d52da X-MS-Exchange-Transport-CrossTenantHeadersStamped: CO2PR0501MB901 --_000_CO2PR0501MB9033E2DE3D5FE30B32EBB08B93C0CO2PR0501MB903na_ Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Charlie, The regulator in the test was close to the fuel tank. The transfer pump out= let line was tee'd into the existing fuel line between the regulator and th= e fuel rail. The fuel rail is dead ended so any air introduced would have t= o be purged through the fuel injectors. The test was done at idle while wa= rming up so the effect on the fuel/air mixture of increasing the fuel rail = pressure may not have been noticeable. I wasn't particularly interested in= trying to work with the open auxiliary fuel tank while in the 100+ mph pro= p blast at high power settings. Today I measured the pressure the transfer pump is capable of producing as= it draws air into it. With an 11 ft length of -4 tubing running from the = pump outlet back to the fuel container, the pressure at the pump outlet was= 12 psi when pumping only fuel. When the pump was running out of fuel and = pumping fuel and bubbles of air, it could maintain about 5 psi of pressure = at the pump outlet. When there was just air in the system, the pump outlet= pressure was about 1 psi or less. The only back pressure in the system wa= s that developed by the 11 ft length of -4 tubing emptying into the fuel co= ntainer. The results seem to indicate that the transfer pump was not capable of pump= ing air into the pressurized section of the fuel system. If air had been i= ntroduced into the fuel rail it would have had to exit through the fuel inj= ectors. That would have been noticeable at the low fuel consumption rate a= t idle. Why the 11 ft length of -4 tubing? That's approximately the length of the = vent line in my plane. In an earlier email I mentioned my concern about ov= erpressuring the fuel tank if the vent system malfunctioned. It's been a n= umber of years since I eliminated the fuel transfer system in my plane. I = now remember that the concern was also related to the possible pressure bui= ldup in the tank if fuel was transferred to a full tank and the transferred= fuel had to exit through the vent line. Today's test put some numbers on = that condition. It is recommended when leak testing the fuel tanks not to = pressurize the tank to more than about 1 psi with 3-4 psi as "far too much"= . The 12 psi generated by the 11 ft length of -4 tubing without any fittin= gs or bug screen at the outlet would not be caused by a vent malfunction. = My conclusion, for what it is worth, is to be very careful to turn off the = transfer pump before the receiving tank is full if the stock vent system is= installed. Steve Boese ________________________________ From: Rotary motors in aircraft on behalf of = Charlie England Sent: Wednesday, March 22, 2017 6:35:24 AM To: Rotary motors in aircraft Subject: [FlyRotary] Re: fuel system peer review That is very interesting! I'd have thought there would at least be some stu= mbling while the xfer pump was pumping air, or running very rich while rail= pressure was 8psi above normal. In your test setup, was the regulator at the fuel rail ('looped' from rail = back to tank), or near the supply tank, with a 'dead head' run to the fuel = rail? Many thanks for running the test; I'd almost decided to go back to 'convent= ional' plumbing. Now I'm back in analysis paralysis... BTW, are you flying the Renesis yet? Charlie On Tue, Mar 21, 2017 at 5:56 PM, Steven W. Boese > wrote: Charlie, I forgot to mention that the engine never missed a beat the entire time tha= t the transfer pump test was made. Steve ________________________________ From: Rotary motors in aircraft > on behalf of Steven W. Boese > Sent: Tuesday, March 21, 2017 4:52:53 PM To: Rotary motors in aircraft Subject: [FlyRotary] Re: fuel system peer review Charlie, I installed a system similar to your proposed diagram on my test stand toda= y. I used one gerotor fuel injection pump taking fuel from a separate sour= ce and tee'd it into the line between the fuel pressure regulator and the d= ead-ended fuel rail. When this pump was turned on, the fuel pressure in th= e rail increased by about 8 psi (that setup uses 5/16 OD steel tubing so th= e pressure increase with -6 tubing would most likely be less). When the in= let to that transfer pump was unported, the fuel pressure returned to norma= l at which time I turned the transfer pump off. With the transfer pump tur= ned off, there was a dribble of fuel coming out of the that pump's inlet. = Apparently, that pump does not completely stop the reverse flow of fuel thr= ough it when there is pressure in the fuel rail. As a result, when the inl= et to the transfer pump was placed back below the level in the auxiliary so= urce and the pump was turned back on, it immediately began pumping fuel int= o the pressurized line. Any air drawn into the pump had been purged back o= ut the pump's inlet. If your transfer pump has the same imperfect check valve action, your propo= sed system appears to work fine in spite of my air lock reservations. Your= selector valve with the "off" position would prevent long term reverse flo= w of fuel through the transfer pump when it is shut off. FWIW Steve Boese ________________________________ From: Rotary motors in aircraft > on behalf of Charlie England > Sent: Tuesday, March 21, 2017 2:55:54 PM To: Rotary motors in aircraft Subject: [FlyRotary] Re: fuel system peer review I did consider it, but that would mean 3 xfer pumps instead of 1+backup. I'= d still need a pair of injection pumps. In the same vein, I considered the = little turbine style in-tank pumps for that purpose, but then I'd need a po= sitive shutoff valve for the aux tanks. I also considered them for injectio= n pumps (lighter, smaller, lower power consumption) but they're actually ha= rder to mount with any configuration flexibility and I'd again need a separ= ate positive cutoff (gerotor pumps are positive cutoff when not running). Thanks, Charlie On 3/21/2017 10:33 AM, Ernest Christley wrote: At the point you're at, what would be the downside to simply putting a pump= in each tank, and using a rotary switch to select? Having the main tank w= ith the return wired in with the ignition, so that it is always running to = avoid the return overfilling the tank. On Mar 20, 2017 5:26 PM, Charlie England wrote: 1st, let me define my delivery architecture. I like Tracy's idea of feeding= the engine from one tank, and transferring aux tanks to the main tank. I u= nderstand the downside of being unable to switch tanks, but many a/c (inclu= ding turbines) supply from one tank, so that's my choice. It avoids the nee= d for a duplex fuel selector, which I like. Effectively, I have 3 'aux' tan= ks, and I'm using the stock (3 inlet) Van's RV fuel selector to feed redund= ant transfer pumps in parallel. I know that most have a separate return port in their tank(s) for regulator= return. With my need for aux transfer, my original plan was to 'T' the aux= transfer line into the regulator return line, which I'm pretty sure has be= en done before. I'm currently working on installing both injection pumps in the fuel tank, = conceptually similar to standard auto practice for the last couple of decad= es: no risk of vapor lock with the added bonus of a very clean installation= . The regulator will be in the wingroot, just outside the tank, with the ma= nifold pressure line running to that location for pressure control. (Deadhe= ading fuel to the fuel rail has been done on both cars and a/c successfully= ; I believe it's an option on the new SDS system being marketed to Lyc driv= ers now.) The recent thread on fuel pressure changes while running both injection pum= ps got me thinking. If it's typical to see only a couple of PSI change when= running both pumps, has anyone considered running the transfer line into t= he regulator? The reason I'm considering this is twofold. It provides a 'fi= nal option' for short term fuel delivery if both injection pumps are lost, = and, because the regulator is in the wingroot, I would need to run only one= fuel line to the supply tank. I'll be using gerotor style transfer pumps (positive displacement) and the = aux selector has an 'off' position, so backflow won't be an issue. A quick & dirty sketch is attached, diagramming the idea. There would never be more than 2 pumps running at any time, since transfers= would only happen in cruise flight. Can anyone poke holes in this arrangem= ent? Charlie -- Homepage: http://www.flyrotary.com/ Archive and UnSub: http://mail.lancaironline.net:81/lists/flyrotary/List.= html --_000_CO2PR0501MB9033E2DE3D5FE30B32EBB08B93C0CO2PR0501MB903na_ Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

Charlie,


The regulator in the test was close to the fuel tank. The transfer = pump outlet line was tee'd into the existing fuel line between th= e regulator and the fuel rail. The fuel rail is dead ended so any air = introduced would have to be purged through the fuel injectors.  The test was done at idle while warming up so the effect = on the fuel/air mixture of increasing the fuel rail pressure may not have b= een noticeable.  I wasn't particularly interested in trying to work wi= th the open auxiliary fuel tank while in the 100+ mph prop blast at high power settings. 


Today I measured the  pressure the transfer pump is capable of prod= ucing as it draws air into it.  With an 11 ft length of -4 tubing runn= ing from the pump outlet back to the fuel container, the pressure at the pu= mp outlet was 12 psi when pumping only fuel.  When the pump was running out of fuel and pumping fuel and bubbles of air,= it could maintain about 5 psi of pressure at the pump outlet.  When t= here was just air in the system, the pump outlet pressure was about 1 psi o= r less.  The only back pressure in the system was that developed by the 11 ft length of -4 tubing emptying i= nto the fuel container.


The results seem to indicate that the transfer pump was not capable of p= umping air into the pressurized section of the fuel system.  If air ha= d been introduced into the fuel rail it would have had to exit through the = fuel injectors.  That would have been noticeable at the low fuel consumption rate at idle.


Why the 11 ft length of -4 tubing?  That's approximately the length= of the vent line in my plane.  In an earlier email I mentioned my con= cern about overpressuring the fuel tank if the vent system malfunctioned.&n= bsp; It's been a number of years since I eliminated the fuel transfer system in my plane.  I now remember that the concer= n was also related to the possible pressure buildup in the tank if fue= l was transferred to a full tank and the transferred fuel had to exit = through the vent line.  Today's test put some numbers on that condition.  It is recommended when leak testing the fuel tank= s not to pressurize the tank to more than about 1 psi with 3-4 psi as = "far too much".  The 12 psi generated by the 11 ft length of= -4 tubing without any fittings or bug screen at the outlet would not be caused by a vent malfunction.  My conclusion, for w= hat it is worth, is to be very careful to turn off the transfer pump before= the receiving tank is full if the stock vent system is installed.


Steve Boese      

From: Rotary motors in airc= raft <flyrotary@lancaironline.net> on behalf of Charlie England <f= lyrotary@lancaironline.net>
Sent: Wednesday, March 22, 2017 6:35:24 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: fuel system peer review
 
That is very interesting! I'd have thought there would at = least be some stumbling while the xfer pump was pumping air, or running ver= y rich while rail pressure was 8psi above normal. 

In your test setup, was the regulator at the fuel rail ('looped' from = rail back to tank), or near the supply tank, with a 'dead head' run to the = fuel rail? 

Many thanks for running the test; I'd almost decided to go back to 'co= nventional' plumbing. Now I'm back in analysis paralysis...

BTW, are you flying the Renesis yet?

Charlie

On Tue, Mar 21, 2017 at 5:56 PM, Steven W. Boese= <flyrot= ary@lancaironline.net> wrote:

Charlie,


I forgot to mention that the engine never missed a beat the entire time = that the transfer pump test was made.


Steve

From: Rotary motors in aircraft <flyrotary@lancaironline.net> on = behalf of Steven W. Boese <flyrotary@lancaironline.net>
Sent: Tuesday, March 21, 2017 4:52:53 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: fuel system peer review
 

Charlie,


I installed a system similar to your proposed diagram on my test stand t= oday.  I used one gerotor fuel injection pump taking fuel from a = separate source and tee'd it into the line between the fuel pressure regula= tor and the dead-ended fuel rail.  When this pump was turned on, the fuel pressure in the rail increased by about 8 psi= (that setup uses 5/16 OD steel tubing so the pressure increase with -6 tub= ing would most likely be less).  When the inlet to that transfer pump = was unported, the fuel pressure returned to normal at which time I turned the transfer pump off.  With the tra= nsfer pump turned off, there was a dribble of fuel coming out of the that p= ump's inlet.  Apparently, that pump does not completely stop the rever= se flow of fuel through it when there is pressure in the fuel rail.  As a result, when the inlet to the transfer pump w= as placed back below the level in the auxiliary source and the pump was tur= ned back on, it immediately began pumping fuel into the pressurized li= ne.  Any air drawn into the pump had been purged back out the pump's inlet.


If your transfer pump has the same imperfect check valve action, your pr= oposed system appears to work fine in spite of my air lock reservations.&nb= sp; Your selector valve with the "off" position would preven= t long term reverse flow of fuel through the transfer pump when it is shut off.  


FWIW


Steve Boese  

From: Rotary motors in aircraft <flyrotary@lancaironline.net> on = behalf of Charlie England <flyrotary@lancaironline.net>
Sent: Tuesday, March 21, 2017 2:55:54 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: fuel system peer review
 
I did consider it, but that would mean 3 xfer pumps instead of 1+ba= ckup. I'd still need a pair of injection pumps. In the same vein, I conside= red the little turbine style in-tank pumps for that purpose, but then I'd need a positive shutoff valve for the aux t= anks. I also considered them for injection pumps (lighter, smaller, lower p= ower consumption) but they're actually harder to mount with any configurati= on flexibility and I'd again need a separate positive cutoff (gerotor pumps are positive cutoff when not run= ning).

Thanks,

Charlie

On 3/21/2017 10:33 AM, Ernest Christley wrote:
At the point you're at, what would be the downside to sim= ply putting a pump in each tank, and using a rotary switch to select? = Having the main tank with the return wired in with the ignition, so that i= t is always running to avoid the return overfilling the tank.

On Mar 20, 2017 5:26 PM, Charlie England <flyrotary@lancaironline.net> wrote:
1st, let me define my delivery architecture. I like Tracy's idea of fe= eding the engine from one tank, and transferring aux tanks to the main tank= . I understand the downside of being unable to switch tanks, but many a/c (= including turbines) supply from one tank, so that's my choice. It avoids the need for a duplex fuel select= or, which I like. Effectively, I have 3 'aux' tanks, and I'm using the stoc= k (3 inlet) Van's RV fuel selector to feed redundant transfer pumps in para= llel. 

I know that most have a separate return port in their tank(s) for regu= lator return. With my need for aux transfer, my original plan was to 'T' th= e aux transfer line into the regulator return line, which I'm pretty sure h= as been done before.

I'm currently working on installing both injection pumps in the fuel t= ank, conceptually similar to standard auto practice for the last couple of = decades: no risk of vapor lock with the added bonus of a very clean install= ation. The regulator will be in the wingroot, just outside the tank, with the manifold pressure line runni= ng to that location for pressure control. (Deadheading fuel to the fuel rai= l has been done on both cars and a/c successfully; I believe it's an option= on the new SDS system being marketed to Lyc drivers now.)

The recent thread on fuel pressure changes while running both injectio= n pumps got me thinking. If it's typical to see only a couple of PSI change= when running both pumps, has anyone considered running the transfer line i= nto the regulator? The reason I'm considering this is twofold. It provides a 'final option' for short term f= uel delivery if both injection pumps are lost, and, because the regulator i= s in the wingroot, I would need to run only one fuel line to the supply tan= k.

I'll be using gerotor style transfer pumps (positive displacement) and= the aux selector has an 'off' position, so backflow won't be an issue.

A quick & dirty sketch is attached, diagramming the idea.

There would never be more than 2 pumps running at any time, since tran= sfers would only happen in cruise flight. Can anyone poke holes in this arr= angement? 

Charlie

<= /font>
--
Homepage:  htt=
p://www.flyrotary.com/
Archive and UnSub:   http://mail.lancaironline.net:=
81/lists/flyrotary/List.html


--_000_CO2PR0501MB9033E2DE3D5FE30B32EBB08B93C0CO2PR0501MB903na_--