X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from wf-out-1314.google.com ([209.85.200.170] verified) by logan.com (CommuniGate Pro SMTP 5.2.0) with ESMTP id 2785330 for flyrotary@lancaironline.net; Mon, 10 Mar 2008 12:00:38 -0400 Received-SPF: pass receiver=logan.com; client-ip=209.85.200.170; envelope-from=rwstracy@gmail.com Received: by wf-out-1314.google.com with SMTP id 28so1933705wfa.25 for ; Mon, 10 Mar 2008 08:59:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:message-id:date:from:sender:to:subject:in-reply-to:mime-version:content-type:references:x-google-sender-auth; bh=AEcXqotPKht4vI+oQ14RhEps3dwaz3nq0tnwH1/mb9A=; b=RBopw7ZUu4m+a9qeOLeJ7CidzdIo/5OJCdlo7rBv0iRXIgqur/eoCQEqH4x7UpMg/3VBqPstNPT6T1CtK91laOXOuGBp662qraIFhRC1ogQ0BmeweZm8ORoQh/FxpMQsw0jCt7YCKmvXAKnZoh5oQhiBMcFq4s0JgrrPVyFv5tk= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:sender:to:subject:in-reply-to:mime-version:content-type:references:x-google-sender-auth; b=s2ic30e+tLwQ3KaHEcxYtHz2+Thz8ptbqL9a6qkmby6gA7H1dUQKSkv058Gn8nc4yTVvdB67MFcrKxxLZ7zAphTKMtXDljOqQxSepgFLbecP1gRB/ZC5xmCNGMPed5QJbN/TEakHiQ1b4GEegGa1PQYfNPdf/D2KYxm4nOJeeJ8= Received: by 10.142.86.7 with SMTP id j7mr1838429wfb.78.1205164797818; Mon, 10 Mar 2008 08:59:57 -0700 (PDT) Received: by 10.143.125.5 with HTTP; Mon, 10 Mar 2008 08:59:57 -0700 (PDT) Message-ID: <1b4b137c0803100859r457360b1ic6986a9cbf828d9e@mail.gmail.com> Date: Mon, 10 Mar 2008 11:59:57 -0400 From: "Tracy Crook" Sender: rwstracy@gmail.com To: "Rotary motors in aircraft" Subject: Re: [FlyRotary] Re: Emailing: Inclinded Radiators.doc In-Reply-To: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_Part_9030_3707887.1205164797838" References: X-Google-Sender-Auth: 677612ee1e9a5af8 ------=_Part_9030_3707887.1205164797838 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline Yeah, I was wondering about that myself. Did they fill up the gap left by the rad as it was inclined by using a bigger rad? If so, the rad was not a fixed factor so the data is not too meaningful. Ignoring that is like ignoring the angle and saying that a bigger rad gave them 30% more cooling. Well Duh.. :>) Tracy On Sun, Mar 9, 2008 at 8:16 PM, Ernest Christley wrote: > Ed Anderson wrote: > > Sorry, Al, there was not any more to be had out of that document. I can > understand that all angles of inclination may not be equal - in heat > transfer or drag, but must admit I was surprised to find that 55deg > supposedly provided 30% more heat transfer and 20% less drag than one > perpendicular to the air flow. It would be interesting to find out the > source of such a conclusion - I mean the graph looks like it comes from > somewhere{:>) > > > The last sentence is interesting, and may be the key to their finding: > > Due to the use of larger radiator, weight incensement finally eliminates > the benefits gained by an inclined radiator... > > So it appears that they have a set amount of room for a radiator. Set > vertical, the rad is small doesn't cool well and the air is still moving > fast so it makes a lot of drag. Lay it over, and you increase the > frontal area and increase radiator volume. The air has expanded, thus > moving slower, reducing drag. > > We tend to start with a required amount of cooling, and let that lead us > to how much radiator we need. We design that in, whatever it takes. > This approach starts with a given volume, and looks to fill it with the > most cooling possible. > > -- > > http://www.ronpaultimeline.com > > > > -- > Homepage: http://www.flyrotary.com/ > Archive and UnSub: > http://mail.lancaironline.net:81/lists/flyrotary/List.html > ------=_Part_9030_3707887.1205164797838 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline
Yeah, I was wondering about that myself.  Did they fill up the gap left by the rad as it was inclined by using a bigger rad?  If so, the rad was not a fixed factor so the data is not too meaningful.  Ignoring that is like ignoring the angle and saying that a bigger rad gave them 30% more cooling.  Well Duh.. :>)
 
Tracy

On Sun, Mar 9, 2008 at 8:16 PM, Ernest Christley <echristley@nc.rr.com> wrote:
Ed Anderson wrote:
> Sorry, Al, there was not any more to be had out of that document.  I can understand that all angles of inclination may not be equal - in heat transfer or drag, but must admit I was surprised to find that 55deg supposedly provided 30% more heat transfer and 20% less drag than one perpendicular to the air flow.  It would be interesting to find out the source of such a conclusion - I mean the graph looks like it comes from somewhere{:>)
>
The last sentence is interesting, and may be the key to their finding:

Due to the use of larger radiator, weight incensement finally eliminates
the benefits gained by an inclined radiator...

So it appears that they have a set amount of room for a radiator.  Set
vertical, the rad is small doesn't cool well and the air is still moving
fast so it makes a lot of drag.  Lay it over, and you increase the
frontal area and increase radiator volume.  The air has expanded, thus
moving slower, reducing drag.

We tend to start with a required amount of cooling, and let that lead us
to how much radiator we need.  We design that in, whatever it takes.
This approach starts with a given volume, and looks to fill it with the
most cooling possible.

--

http://www.ronpaultimeline.com



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