X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mail-wg0-f42.google.com ([74.125.82.42] verified) by logan.com (CommuniGate Pro SMTP 6.0.8) with ESMTPS id 6745941 for flyrotary@lancaironline.net; Sun, 23 Feb 2014 17:59:53 -0500 Received-SPF: pass receiver=logan.com; client-ip=74.125.82.42; envelope-from=ceengland7@gmail.com Received: by mail-wg0-f42.google.com with SMTP id k14so2264898wgh.1 for ; Sun, 23 Feb 2014 14:59:17 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; bh=vf2vQbj+DC106velejL8/aQWlKyXgsKwsVGOTkPMSJ0=; b=LX6A9q7houDlq6Q6vDLovX6QplGQk3/zydfPI5stZclBkm1mhcarPq2CB+coDZMisE cr2s+Ew6ejZOLIpLwuATJIQkP3I1YAozBO0ug7X42nrv9ODeHg2KIX4rTiR/npYC1SLB hnLk2eFh9JbIh9BvnPsAO2Zwgf8y8TU6NXZhKA+4R/C/D65pIh10fpkXK4IdVkUODSDz Xe5kYU+DMNzfBlUXdyEPv/prD79myoIDeK775KW/fRc8aJlBGxZ3etdvpr5I8cF/R0GQ Xy3CO9mUXdWja1Gmq71i1cRTHcPMclTZK6eiO0O/fbzT0rmbu/keazeiF1t1kYYSuu6s mKyg== MIME-Version: 1.0 X-Received: by 10.180.13.33 with SMTP id e1mr11770713wic.38.1393196357313; Sun, 23 Feb 2014 14:59:17 -0800 (PST) Received: by 10.216.221.199 with HTTP; Sun, 23 Feb 2014 14:59:17 -0800 (PST) Received: by 10.216.221.199 with HTTP; Sun, 23 Feb 2014 14:59:17 -0800 (PST) In-Reply-To: References: Date: Sun, 23 Feb 2014 16:59:17 -0600 Message-ID: Subject: Re: [FlyRotary] Re: Vortex Generator in air duct From: Charlie England To: Rotary motors in aircraft Content-Type: multipart/alternative; boundary=001a11c24d66faeaa504f31acd7d --001a11c24d66faeaa504f31acd7d Content-Type: text/plain; charset=ISO-8859-1 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 air to flow out of an attic without letting insects in. Tracy 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 only 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" 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 > strips 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 which is a great asset in cold weather. > > If you are turning air 90 degrees 2 times you'll need excellent ducting. > In contrast to vortex generators, several contributors to this list are > really pinching the air at the back of their plenumns; if you allw 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 [image: Message Header] > > [image: Undecoded Message] > Jeff; > That's a good point. I've heard of that 1:1 ratio, however, I'm using 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 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 > time 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. > -----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 > your operating temperatures relative to ambient air temperature. > If 185F is the cruise result on a 40F day - you should expect 245F in > cruise if the air temperature reaches 100F. In other words, you're not > quite there yet; winter is an excellent 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 40F. It is not easy to design for both ends > of the spectrum ... > Jeff > This message, and the documents attached hereto, is intended only > for the addressee and may contain privileged or confidential information. > Any unauthorized 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. > --001a11c24d66faeaa504f31acd7d Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable

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 a= nd the cap. It allows air to flow out of an attic without letting insects i= n. Tracy packed it in the back of his wedge diffuser to limit the excess fl= ow and force more air through the forward part of the core.

BTW, the vortex generator looks pretty big. Have you tried s= everal smaller ones spread across that surface? Most VGs I've seen are = only about 1/2" tall. Multiple smaller ones might get the job done wit= h less resistance to flow.

FWIW,

Charlie

On Feb 23, 2014 3:18 PM, "Jeff Whaley"= <jwhaley@datacast.com> w= rote:

I'm not sure about the roof-ridge material either but perhaps he mea= nt cutting small strips from an aluminum ridge-cap, allowing the peaks slig= ht protrusion into the air stream and riveting on the flats -- there are st= rips 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 temperatu= re which is a great asset in cold weather.

If you are turning air 90 degrees 2 times you'll need excellent duct= ing.  In contrast to vortex generators, several contributors to t= his list are really pinching the air at the back of their plenumns; if you = allw 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.co= m
Subject: Re: [FlyRotary] Re: [Fly Rotary] Vortex Generator in air duct
Date: Fri, 21 Feb 2014 23:26:19 -0500 (EST)
To: flyrot= ary@lancaironline.net
3D"Message

3D"Undecoded
Jeff;
That's a good point. I've heard of that 1:1 ratio, however,&nb= sp;I'm using the stock Mazda oil cooler with a 170F Thermostat. In my c= ase, 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 time to start flight testing, and also I probably need more impr= ovement as the weather warms.
Tracy suggested 'roof ridge material', which I couldn't fi= gure out. Perhaps he meant a loose strand media that serves to sl= ow 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.  &n= bsp;        
-----Original Mes= sage-----
From: Jeff Whaley <jwhaley@datacast.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 – = you should expect 245F in cruise if the air temperature reaches 100F.  = ;In other words, you’re not quite there yet; winter is an excellent t= ime 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 …
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.
--001a11c24d66faeaa504f31acd7d--