X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from www.whiteaspen.com ([66.180.170.33] verified) by logan.com (CommuniGate Pro SMTP 5.0.8) with ESMTP id 1029805 for flyrotary@lancaironline.net; Fri, 10 Mar 2006 14:51:39 -0500 Received-SPF: neutral receiver=logan.com; client-ip=66.180.170.33; envelope-from=sladerj@bellsouth.net Received: from [10.1.1.50] (unknown [10.101.1.6]) by www.whiteaspen.com (Postfix) with ESMTP id D0397B803B for ; Fri, 10 Mar 2006 14:50:55 -0500 (EST) Message-ID: <4411D89F.1030904@bellsouth.net> Date: Fri, 10 Mar 2006 14:50:55 -0500 From: john slade User-Agent: Mozilla Thunderbird 1.0.7 (X11/20051013) X-Accept-Language: en-us, en MIME-Version: 1.0 To: Rotary motors in aircraft Subject: Re: [FlyRotary] Re: NACA's, Cooling and Sport Aviation Mag.. References: In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit This would be Eric Westland. He did some oil trail tests and ended up with much improved cooling using vortex generators 1" * 4" vortex generators at 45 degrees to the airstream ahead of the NACA (or whatever you want to call the plans Cozy scoop). The results are up on a web site somewhere. Based on his results I installed the same generators from day one. I have no measurements with them not in place. John Slade aheaJames wrote: > I read an article (don't remember where) about a fellow who placed two > vortex generator tabs just in front of the NACA ducts. This improved > efficiency quite a lot. He had to experiment a while to get it right; > but, liked the results. I think it was on a Velocity or Cozy. > > This makes perfect sense. As I remember when I read the initial NACA > report. The paper indicated that the duct was efficient for large > volume flows which created little back pressure. > Thus, my analysis of the operation is that the efficiency of the duct > depends on a bit of local turbulence at the duct to break the local > boundary layer. A high flow rate, as the original paper indicated > and/or required, would do that. Also a set of vortex generators in > front of the duct would also do the same. > > Second point: I believe that a reversed direction NACA scoop would > make an excellent low drag exit port for the cooling air stream. > Such a scoop design would tend to form a small low- drag partial > vacuum at that point, allowing the exit scoop to literally help suck > the air out. This would improve cooling efficiency I.E. NACA in, and > ACAN out. > I hold several patents, but I am not going to pursue this idea on that > basis. I think it has a good possibility of being a very efficient > low drag cooling system. > > If anyone tries it, please let us know your findings. > > Best Regards; > > James Freeman > > > > David Staten wrote: > >> I skimmed it.. Chris and I are actually considering armpit scoops for >> cooling, but we still have this nagging urge to minimize deviations >> from plans. I will go back and do more than just skim.. >> >> All I saw was NACA's, Cooling and immediately thought of PL.. >> >> Dave >> >> Bulent Aliev wrote: >> >>> You are right Bill. David did not read the whole article. Or he >>> didn't want to hear it? :) >>> Buly >>> >>> >>> >>> On Mar 9, 2006, at 8:58 PM, Bill Dube wrote: >>> >>>> I read that article as well. I had the same skepticism about the >>>> NACA intake for cooling. My understanding is that with an NACA >>>> inlet, you don't get the ram pressure you need to force air >>>> through a high fin-count radiator. Am I wrong about this? >>>> >>>> Bill Dube' >>>> >>>> David Staten wrote: >>>> >>>>> At the risk of invoking PL's name, anyone else read this months >>>>> Sport Aviation mag from EAA, and notice an article on cooling >>>>> that seems to indicate that NACA's are acceptable and adequate >>>>> for aircraft cooling needs? I have no idea regarding the authors >>>>> credentials, and I no longer monitor PL's "newsletter".. I was >>>>> curious more than anything else... Pauls reaction, others >>>>> reactions, etc. >>>>> >>>>> Translation.. yes.. I'm stirring the pot/Trolling... I figure if >>>>> we are using NACA's on the Velocity, that makes us somewhat of a >>>>> NACA supporter.. >>>>> >>>>> Dave >>>>> >>>>> -- >>>>> Homepage: http://www.flyrotary.com/ >>>>> Archive and UnSub: http://mail.lancaironline.net/lists/flyrotary/ >>>>> >>>> >>>> -- >>>> Homepage: http://www.flyrotary.com/ >>>> Archive and UnSub: http://mail.lancaironline.net/lists/flyrotary/ >>> >>> >>> >>> >>> >>> -- >>> Homepage: http://www.flyrotary.com/ >>> Archive and UnSub: http://mail.lancaironline.net/lists/flyrotary/ >>> >> >> >> -- >> Homepage: http://www.flyrotary.com/ >> Archive and UnSub: http://mail.lancaironline.net/lists/flyrotary/ >> >> . >> > > > -- > Homepage: http://www.flyrotary.com/ > Archive and UnSub: http://mail.lancaironline.net/lists/flyrotary/ >