X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from cdptpa-omtalb.mail.rr.com ([75.180.132.120] verified) by logan.com (CommuniGate Pro SMTP 5.2.0) with ESMTP id 2799292 for flyrotary@lancaironline.net; Wed, 19 Mar 2008 20:28:25 -0400 Received-SPF: pass receiver=logan.com; client-ip=75.180.132.120; envelope-from=eanderson@carolina.rr.com Received: from edward2 ([75.191.186.236]) by cdptpa-omta02.mail.rr.com with SMTP id <20080320002747.SIVX28190.cdptpa-omta02.mail.rr.com@edward2> for ; Thu, 20 Mar 2008 00:27:47 +0000 Message-ID: <000401c88a21$3faebff0$2402a8c0@edward2> From: "Ed Anderson" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Emailing: Inclinded Radiators.doc Date: Wed, 19 Mar 2008 20:27:58 -0400 MIME-Version: 1.0 Content-Type: text/plain; format=flowed; charset="Windows-1252"; reply-type=original Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.3138 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3198 Hi Charlie, Yes, several folks have pointed out variables that may have contributed to the "increased" effectiveness of the inclined radiator. Al, pointed out that the inlet appeared to be the old "sinsodal" type which almost guaranteed early flow separation and poorer cooling. So then if you incline a larger radiator - the added area alone would contribute to better cooling - and if inclining it had a favorable influence on "smoothing" out the air flow - the cooling would appear more effective with an inclined radiator that a perpendicular one. Whereas a perpendicular one of the same size as the inclinded one would beat. Ah! Such fun! How are you and Tupper doing? Going to S&F this year? Ed ----- Original Message ----- From: "Charlie England" To: "Rotary motors in aircraft" Sent: Wednesday, March 12, 2008 3:59 PM Subject: [FlyRotary] Re: Emailing: Inclinded Radiators.doc > Ed Anderson wrote: >> Here is an extract out of an article on race car cooling that is very >> interesting about use of inclined radiators. Unfortunately, I could not >> find any reference as to where this information was derived from - but, >> if correct, is fairly significant. >> It basically states that inclining a radiator from 0 deg to 20-30 deg >> will decrease cooling and increase drag - not terribly surprising, >> however, the article continues saying that at approx. 55 dig of >> inclination the cooling effectiveness is 30% greater than a radiator with >> no inclination and the drag is 20% less!!! Now I found that surprising - >> but, then air flow does take surprising twists (no pun intended). >> While I find that claim very interesting - I have not found any >> collaborating documents. But, thought the group might find it >> interesting >> For your information >> Ed > > I learned a long time ago (Maybe it was Mr. Wizard & blocks sliding down a > ramp...??) that with physics, what looks right or sounds right probably > isn't. > > But this one looks like a trick question. Notice the mention of 'larger > radiator'? Perhaps the original inlet vs. core density wasn't set up > correctly & they were trying to force too much air through the core. When > they tilted the radiator, they apparently also made it bigger, meaning > more fin area *and* more open area for the same inlet/outlet areas. > > But like I said, what sounds right, rarely is, if it's me doing the > listening... > > Charlie > > -- > Homepage: http://www.flyrotary.com/ > Archive and UnSub: > http://mail.lancaironline.net:81/lists/flyrotary/List.html >