X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from omr-m08.mx.aol.com ([64.12.222.129] verified) by logan.com (CommuniGate Pro SMTP 6.0.8) with ESMTPS id 6753221 for flyrotary@lancaironline.net; Fri, 28 Feb 2014 01:13:46 -0500 Received-SPF: pass receiver=logan.com; client-ip=64.12.222.129; envelope-from=shipchief@aol.com Received: from mtaomg-mcd02.mx.aol.com (mtaomg-mcd02.mx.aol.com [172.26.223.208]) by omr-m08.mx.aol.com (Outbound Mail Relay) with ESMTP id 33F8A7000008C for ; Fri, 28 Feb 2014 01:13:11 -0500 (EST) Received: from core-dda001c.r1000.mail.aol.com (core-dda001.r1000.mail.aol.com [172.29.52.1]) by mtaomg-mcd02.mx.aol.com (OMAG/Core Interface) with ESMTP id CCD4538000084 for ; Fri, 28 Feb 2014 01:13:10 -0500 (EST) References: To: flyrotary@lancaironline.net Subject: Re: [FlyRotary] Re: Vortex Generator in air duct In-Reply-To: X-MB-Message-Source: WebUI MIME-Version: 1.0 From: shipchief@aol.com X-MB-Message-Type: User Content-Type: multipart/alternative; boundary="--------MB_8D102634A37C551_1EDC_1C250_webmail-m169.sysops.aol.com" X-Mailer: AOL Webmail 38427-STANDARD Received: from 184.78.169.203 by webmail-m169.sysops.aol.com (64.12.159.4) with HTTP (WebMailUI); Fri, 28 Feb 2014 01:13:10 -0500 Message-Id: <8D102634A2BDE6C-1EDC-7E12@webmail-m169.sysops.aol.com> X-Originating-IP: [184.78.169.203] Date: Fri, 28 Feb 2014 01:13:10 -0500 (EST) x-aol-global-disposition: G DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mx.aol.com; s=20121107; t=1393567991; bh=6zLbaKwom5/HSOaPiafmhz+GhmODDBBKF6paVhPfZYE=; h=From:To:Subject:Message-Id:Date:MIME-Version:Content-Type; b=qz1rVChzE+RHxEqDMV4C1XyI5Iqs8CAhZAXuxceOHEUfsHsgROOz6qr8Rxdw2aMm/ 9uZyDzNeb5ck8iTahDBje+rvIk5ZQ8a3yI73MJ77C0AtffeWx8hpX7+4bV27QLIwQh w5smRAuZLCx8pQza70SIibNh+R6PO1IhUZbzIpgw= x-aol-sid: 3039ac1adfd0531028f63c76 This is a multi-part message in MIME format. ----------MB_8D102634A37C551_1EDC_1C250_webmail-m169.sysops.aol.com Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Charlie and all; The vortex generator must look larger in the pic than in real life. The pro= totype is .4" tall, the one in the pic is about .5" tall. I mounted it just= aft of the divergent throat and wanted to be sure it's tall enough to snag= some air. I'm planning to keep it and re-shape the duct as per Steve Boese' reference= . The cowl inlet is mounted higher than the cooler, so the airflow still ne= eds to be pulled down before it gets squeezed thru the cooler core. The co-= ordinates provided will need some interpretation for diagonal flow across t= he face of the cooler. It's not like I could make a fiberglass part accurat= e to .01 X or Z anyway? The cut down and re-make will also reduce weight an= d give more access, so I'm looking forward to doing it. I did make a flow ramp for the jacket water Radiator, without the knowledge= of this study, just a general description from this group. The 'no ramp' v= ersion worked 'ok'. The cardboard trial ramp was a big improvement, and the= final fiberglass over foam version is a real winner. There is a future pos= sibility that I could switch to a smaller lighter radiator. Lets just say i= t's not a problem, so it stays while I work on other things! -----Original Message----- From: Charlie England To: Rotary motors in aircraft Sent: Sun, Feb 23, 2014 2:59 pm Subject: [FlyRotary] Re: Vortex Generator in air duct I'm not Tracy, but might be able to help. Ridge vent is porous foam that's = normally placed between a slot cut on a roof ridge and the cap. It allows a= ir to flow out of an attic without letting insects in. Tracy packed it in t= he back of his wedge diffuser to limit the excess flow and force more air t= hrough the forward part of the core.=20 BTW, the vortex generator looks pretty big. Have you tried several smaller = ones spread across that surface? Most VGs I've seen are only about 1/2" tal= l. Multiple smaller ones might get the job done with less resistance to flo= w. FWIW, Charlie On Feb 23, 2014 3:18 PM, "Jeff Whaley" wrote: I'm not sure about the roof-ridge material either but perhaps he meant cutt= ing small strips from an aluminum ridge-cap, allowing the peaks slight prot= rusion into the air stream and riveting on the flats -- there are strips av= ailable for fastening to the lower roof used to prevent large build-ups of = ice -- they resemble vortex generators. I'm happy to see you are enjoying t= he experimental part of your homebuilt. Yes, the thermostat will limit you= r minimum temperature which is a great asset in cold weather. If you are turning air 90 degrees 2 times you'll need excellent ducting. I= n contrast to vortex generators, several contributors to this list are real= ly pinching the air at the back of their plenumns; if you allw too much spa= ce in that location most of the air will pass through the core in a relativ= ely small (1/3 surface) area. Stay with it ... Jeff =20 From: shipchief@aol.com Subject: Re: [FlyRotary] Re: [Fly Rotary] Vortex Generator in air duct Date: Fri, 21 Feb 2014 23:26:19 -0500 (EST) To: flyrotary@lancaironline.net Jeff; That's a good point. I've heard of that 1:1 ratio, however, I'm using the s= tock Mazda oil cooler with a 170F Thermostat. In my case, it will always be= above 170 by some margin, then ambient effects will have their way. I was pleased the Vortex Generator worked so well for such little effort. I= thought I should share it. I'm agreeing with you that winter is a good tim= e to start flight testing, and also I probably need more improvement as the= weather warms. Tracy suggested 'roof ridge material', which I couldn't figure out. Perhaps= he meant a loose strand media that serves to slow the air flow through the= back where most of the air naturally passes, so that some of the air must = pass thru the front of the cooler also? My son Peter suggests the next step could be a partial scoop half way back = that directs some air to the forward part of the cooler. =20 -----Original Message----- From: Jeff Whaley To: Rotary motors in aircraft Sent: Fri, Feb 21, 2014 1:44 pm Subject: [FlyRotary] Re: [Fly Rotary] Vortex Generator in air duct All improvements are good; however, you can expect a 1:1 degree rise in you= r operating temperatures relative to ambient air temperature. If 185F is the cruise result on a 40F day =E2=80=93 you should expect 245F = in cruise if the air temperature reaches 100F. In other words, you=E2=80= =99re not quite there yet; winter is an excellent time to experiment with a= liquid-cooled engine as there is little chance of overheating. Realistica= lly, if you want <200F oil temperature at 100F you need to see <140F oil te= mperature wit OAT 40F. It is not easy to design for both ends of the spect= rum =E2=80=A6 Jeff This message, and the documents attached hereto, is intended only for the a= ddressee and may contain privileged or confidential information. Any unauth= orized disclosure is strictly prohibited. If you have received this message= in error, please notify us immediately so that we may correct our internal= records. Please then delete the original message. Thank you. ----------MB_8D102634A37C551_1EDC_1C250_webmail-m169.sysops.aol.com Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset="utf-8"
Charlie and all;
The vortex generator must look larger in the pic than in real life. Th= e prototype is .4" tall, the one in the pic is about .5" tall. I mounted it= just aft of the divergent throat and wanted to be sure it's tall enough to= snag some air.
I'm planning to keep it and re-shape the duct as per Steve Boese' refe= rence. The cowl inlet is mounted higher than the cooler, so the airflo= w still needs to be pulled down before it gets squeezed thru the cooler cor= e. The co-ordinates provided will need some interpretation for diagonal flo= w across the face of the cooler. It's not like I could make a fiberglass pa= rt accurate to .01 X or Z anyway? The cut down and re-make will also reduce= weight and give more access, so I'm looking forward to doing it.
I did make a flow ramp for the jacket water Radiator, without the= knowledge of this study, just a general description from this group. = The 'no ramp' version worked 'ok'. The cardboard trial ramp was a big impro= vement, and the final fiberglass over foam version is a real winner. T= here is a future possibility that I could switch to a smaller lighter radia= tor. Lets just say it's not a problem, so it stays while I work on other th= ings!
-----Original Message-----
From: Charlie England <ceengland7@gmail.com>
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Sent: Sun, Feb 23, 2014 2:59 pm
Subject: [FlyRotary] Re: Vortex Generator in air duct

I'm not Tracy, but might be able to help. Ridge vent is po= rous foam that's normally placed between a slot cut on a roof ridge and the= cap. It allows air to flow out of an attic without letting insects in. Tra= cy packed it in the back of his wedge diffuser to limit the excess flow and= force more air through the forward part of the core.
BTW, the vortex generator looks pretty big. Have you tried= several smaller ones spread across that surface? Most VGs I've seen are on= ly about 1/2" tall. Multiple smaller ones might get the job done with less = resistance to flow.
FWIW,
Charlie
On Feb 23, 2014 3:18 PM, "Jeff Whaley" <jwhaley@datacast.com> wrote:
I'm not sure about the roof-ridge material either but perhaps he meant= cutting small strips from an aluminum ridge-cap, allowing the peaks slight= protrusion into the air stream and riveting on the flats -- there are stri= ps available for fastening to the lower roof used to prevent large build-ups of ice -- they resemble vortex = generators. I'm happy to see you are enjoying the experimental part of your= homebuilt.  Yes, the thermostat will limit your minimum temperature w= hich is a great asset in cold weather.
If you are turning air 90 degrees 2 times you'll need excellent ductin= g.  In contrast to vortex generators, several contributors to thi= s list are really pinching the air at the back of their plenumns; if you al= lw too much space in that location most of the air will pass through the core in a relatively small (1/3 surface) area.
Stay with it ...
Jeff
 
From: shipchief@aol.com
Subject: Re: [FlyRotary] Re: [Fly Rotary] Vortex Generator in air duct
Date: Fri, 21 Feb 2014 23:26:19 -0500 (EST)
To: flyrotary@lancaironline.= net
3D"Message

3D"Undecoded
Jeff;
That's a good point. I've heard of that 1:1 ratio, however, I'm u= sing the stock Mazda oil cooler with a 170F Thermostat. In my case, it will= always be above 170 by some margin, then ambient effects will have their w= ay.
I was pleased the Vortex Generator worked so well for such little= effort. I thought I should share it. I'm agreeing with you that winter is = a good time to start flight testing, and also I probably need more improvem= ent as the weather warms.
Tracy suggested 'roof ridge material', which I couldn't figure out.&nb= sp;Perhaps he meant a loose strand media that serves to slow the air f= low through the back where most of the air naturally passes, so that some o= f the air must pass thru the front of the cooler also?
My son Peter suggests the next step could be a partial scoop half way = back that directs some air to the forward part of the cooler.  &n= bsp;        
-----Original= Message-----
From: Jeff Whaley <jwhaley@datac= ast.com>
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Sent: Fri, Feb 21, 2014 1:44 pm
Subject: [FlyRotary] Re: [Fly Rotary] Vortex Generator in air duct

All improvements are good; however, you can expect= a 1:1 degree rise in your operating temperatures relative to ambient air t= emperature.
If 185F is the cruise result on a 40F day =E2=80= =93 you should expect 245F in cruise if the air temperature reaches 100F. &= nbsp;In other words, you=E2=80=99re not quite there yet; winter is an excel= lent time to experiment with a liquid-cooled engine as there is little chance of overheating.  Realistically, if you want <200F= oil temperature at 100F you need to see <140F oil temperature wit OAT 4= 0F.  It is not easy to design for both ends of the spectrum =E2=80=A6<= /div>
Jeff
This message, and the documents attached hereto, is intended only for the a= ddressee and may contain privileged or confidential information. Any unauth= orized disclosure is strictly prohibited. If you have received this message= in error, please notify us immediately so that we may correct our internal records. Please then delete the origin= al message. Thank you.
----------MB_8D102634A37C551_1EDC_1C250_webmail-m169.sysops.aol.com--