X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mail-qy0-f200.google.com ([209.85.221.200] verified) by logan.com (CommuniGate Pro SMTP 5.3.1) with ESMTP id 4085258 for flyrotary@lancaironline.net; Sat, 16 Jan 2010 20:36:10 -0500 Received-SPF: pass receiver=logan.com; client-ip=209.85.221.200; envelope-from=rwstracy@gmail.com Received: by qyk38 with SMTP id 38so1087863qyk.25 for ; Sat, 16 Jan 2010 17:35:34 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:sender:received:in-reply-to :references:date:x-google-sender-auth:message-id:subject:from:to :content-type; bh=KCHPhZ8FG53mqIW62cx8RLTUbo4U3X0cjen0/AFwSnw=; b=dL6VChkK27yV4ZKpBmeqXmFPVfxQZgOj75TaoIK4gRiQkfN1b1te91KzqEhQJEkBvy x3rhv/rTx0jhIrWGyTUvrN3L56JUoL5ISJdLxnu0UP9/Rtyn4OjHrQS738UmeIhAcfyD un/DqGG2OWXImJD0MJQF7BxVZlGCCH03DOQt4= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:content-type; b=gh8FtBxTrjuwaQKgKIJR5+JCw/UWZLjlfaDInevheFdebihkMno3wOQYZY8DH4rTvL 2VTsIHxqGeehuJuxsiGS+VF5Y/o8hMxCUFYvD2yDk4p3ij6MuPaYvF+L/VvXRYXuNe6F dcXbytsKehVTQlvtZhSYI5exIWsuMN5FoZzKs= MIME-Version: 1.0 Sender: rwstracy@gmail.com Received: by 10.224.53.91 with SMTP id l27mr3406855qag.305.1263692134737; Sat, 16 Jan 2010 17:35:34 -0800 (PST) In-Reply-To: References: Date: Sat, 16 Jan 2010 20:35:34 -0500 X-Google-Sender-Auth: 47eb2ced141301e2 Message-ID: <1b4b137c1001161735k48d9cb5eu17947d5b391b456c@mail.gmail.com> Subject: Re: [FlyRotary] Re: Inclined Radiators was : [FlyRotary] Re: Scoops From: Tracy Crook To: Rotary motors in aircraft Content-Type: multipart/alternative; boundary=00c09f9db18acbe89b047d524027 --00c09f9db18acbe89b047d524027 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable Well the basic idea has validity because I carried it to an extream. My ra= d is inclined about 80 degrees to the 5" duct so flow axis is almost perpendicular to the duct. A 5" rad would never cool that 20B so inclining it radically was the only answer in my configuration. Water cooling has never been my problem. Oil cooling is working pretty good with the new oil cooler. It was the "30 row oil cooler" from CXracing if anyone is curious. Tracy On Sat, Jan 16, 2010 at 4:18 PM, George Lendich wrote= : > Ed, > I would like to see that again, as I believe would others, like Al and > Thomas. I'm hoping someone tries it in an aircraft to test the theory. > TIA > George ( down under) > > I recall an article on some experiments done on inclined radiators in > race cars. > > > > Basically the figures that George mentioned were quoted in the source. > However (big however) what may not have been clearly pointed out was that > the major part of the reason cooling effectiveness (not efficiency) > increased was that inclining the heat exchanger permitted you to install > ever larger area cores in the same size duct. So the increase in cooling > effectiveness by inclination was in large part due to the larger size > radiator permitted by inclined placement in the duct. > > > > For example take a duct that is 24=94 wide (X) and 12=94 high (Y) at zero > degree inclination. If you incline the radiator by 30 deg and then incre= ase > its height to again fill the duct,. you can get an approx 15% increase in > the frontal size of the radiator (in the same 24x12 duct). At 60 deg you > could gain approx 100% increase in frontal size by again increasing the > height of the core to fill the duct. . Naturally that aids in getting ri= d > of the heat. They also point out the larger core adds weight until you > reach a point where the adverse effect of the heavier radiator core offse= t > its benefit (this was all addressing their use in race cars). > > > > The source indicated that up to 30Deg the drag increases and heat transfe= r > goes down due to uneven air flow distribution and disturbances =96 appare= ntly > above that angle this adverse effect decreases and of course you have the > much larger frontal area.. > > > > At least that is what I recall. If anyone is interested I=92ll see if I = can > find the article in my files > > > > Ed > > Ed Anderson > > Rv-6A N494BW Rotary Powered > > Matthews, NC > > eanderson@carolina.rr.com > > http://www.andersonee.com > > http://www.dmack.net/mazda/index.html > > http://www.flyrotary.com/ > > http://members.cox.net/rogersda/rotary/configs.htm#N494BW > > http://www.rotaryaviation.com/Rotorhead%20Truth.htm > ------------------------------ > > *From:* Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] *O= n > Behalf Of *Al Gietzen > *Sent:* Friday, January 15, 2010 1:13 AM > *To:* Rotary motors in aircraft > *Subject:* [FlyRotary] Re: Scoops > > > > > > Thomas, > > Nice research. > > I found my notes on inclined radiators, they state > > 1. 0-20/30* will decrease cooling and increase drag. > > 2. Over 30* things improve. > > 3. At approx 55* cooling effectiveness is 30% greater than non-inclined > rads > > and drag is less by 20%. > > > > George; do you have the source for that info? It may be a good idea to > verify this information. I don=92t recall the specifics; but what I do r= ecall > is that the conclusion was configuration dependant, and should not be tak= en > as generally applicable. Sorry, but I don=92t remember what the factors = were; > maybe something about the configuration of the core. > > Or maybe my memory just isn=92t right. Worth checking. > > All > > > > __________ Information from ESET NOD32 Antivirus, version of virus > signature database 3267 (20080714) __________ > > The message was checked by ESET NOD32 Antivirus. > > http://www.eset.com > > --00c09f9db18acbe89b047d524027 Content-Type: text/html; charset=windows-1252 Content-Transfer-Encoding: quoted-printable Well the basic idea has validity because I carried it to an extream.=A0 My = rad is inclined about 80 degrees to the 5" duct so flow axis is almost= perpendicular to the duct.=A0 A 5" rad would never cool that 20B so i= nclining it radically was the only answer in my configuration.=A0 Water coo= ling has never been my problem.=A0 Oil cooling is working pretty good with = the new oil cooler.=A0 It was the "30 row oil cooler" from CXraci= ng if anyone is curious.

Tracy

On Sat, Jan 16, 2010 at 4:18 PM= , George Lendich <lendich@aanet.com.au> wrote:
Ed,
I would like to see that again, as I b= elieve would=20 others, =A0like Al and Thomas. I'm hoping someone tries it in an aircra= ft to=20 test the theory.
TIA
George ( down under)

I recall an = article=20 on some experiments done on inclined radiators in race cars.=20

=A0

Basically th= e figures=20 that George mentioned were quoted in the source.=A0 However (big however)= =20 what may not have been clearly pointed out was that the major part of the= =20 reason cooling effectiveness (not efficiency) increased was that inclinin= g the=20 heat exchanger permitted you to install ever larger area cores in the sam= e=20 size duct.=A0 So the increase in cooling effectiveness by inclination was= =20 in large part due to the larger size radiator permitted by inclined place= ment=20 in the duct.

=A0

For example = take a=20 duct that is 24=94 wide (X) and 12=94 high (Y) at zero degree inclination= .=A0=20 If you incline the radiator by 30 deg and then increase its height to aga= in=20 fill the duct,. you can get an approx 15% increase in the frontal size of= the=20 radiator (in the same 24x12 duct).=A0 At 60 deg you could gain approx 100= %=20 increase in frontal size by again increasing the height of the core to fi= ll=20 the duct.=A0 . Naturally that aids in getting rid of the heat.=A0 They=20 also point out the larger core adds weight until you reach a point where = the=20 adverse effect of the heavier radiator core offset its benefit (this was = all=20 addressing their use in race cars).

=A0

The source i= ndicated=20 that up to 30Deg the drag increases and heat transfer goes down due to un= even=20 air flow distribution and disturbances =96 apparently above that angle th= is=20 adverse effect decreases and of course you have the much larger frontal= =20 area..

=A0

At least tha= t is what=20 I recall.=A0 If anyone is interested I=92ll see if I can find the article= in=20 my files

=A0

Ed

<= font size=3D"3" face=3D"Times New Roman">

From:=20 Rotary motors in aircraft=20 [mailto:= flyrotary@lancaironline.net] On= =20 Behalf Of Al Gietzen
= Sent: Friday, January 15, 2010 1:13=20 AM
To: Rotary motors = in aircraft
Subject: [F= lyRotary] Re:=20 Scoops

=A0

=A0<= /span>

Thom= as,

Nice= research.

I=20 found my notes on inclined radiators, they state

1. 0= -20/30* will decrease cooling and increase=20 drag.

2. O= ver 30* things=20 improve.

3. A= t approx 55* cooling effectiveness is 30% greater=20 than non-inclined rads

and = drag is less by 20%.

=A0<= /span>

George; do you=20 have the source for that info? It may be a good idea to verify this=20 information. =A0I don=92t recall the specifics; but what I do recall is t= hat=20 the conclusion was configuration dependant, and should not be taken as=20 generally applicable.=A0 Sorry, but I don=92t remember what the factors w= ere;=20 maybe something about the configuration of the=20 core.

Or maybe my memory=20 just isn=92t right.=A0 Worth checking.

All



__________ Information from ESET NOD32=20 Antivirus, version of virus signature database 3267 (20080714)=20 __________

The message was checked by ESET NOD32 Antivirus.
http://www.eset.com<= /span>


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