X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from misav10.sasknet.sk.ca ([142.165.20.174] verified) by logan.com (CommuniGate Pro SMTP 5.0.8) with ESMTP id 1030249 for flyrotary@lancaironline.net; Fri, 10 Mar 2006 21:04:24 -0500 Received-SPF: none receiver=logan.com; client-ip=142.165.20.174; envelope-from=hjjohnson@sasktel.net Received: from bgmpomr2.sasknet.sk.ca ([142.165.72.23]) by misav10 with InterScan Messaging Security Suite; Fri, 10 Mar 2006 20:03:39 -0600 Received: from home ([204.83.195.66]) by bgmpomr2.sasknet.sk.ca (SaskTel eMessaging Service) with ESMTPA id <0IVX009GZXQ3SG10@bgmpomr2.sasknet.sk.ca> for flyrotary@lancaironline.net; Fri, 10 Mar 2006 20:03:39 -0600 (CST) Date: Fri, 10 Mar 2006 20:03:38 -0600 From: Jarrett & Heidi Johnson Subject: Re: [FlyRotary] Re: NACA's, Cooling and Sport Aviation Mag.. To: Rotary motors in aircraft Message-id: <00bc01c644b0$03233650$6501a8c0@home> MIME-version: 1.0 X-MIMEOLE: Produced By Microsoft MimeOLE V6.00.2900.2180 X-Mailer: Microsoft Outlook Express 6.00.2900.2180 Content-type: text/plain; format=flowed; charset=iso-8859-1; reply-type=response Content-transfer-encoding: 7BIT X-Priority: 3 X-MSMail-priority: Normal References: James If I'm thinking of the same article, it was actually an E-Racer w/ a Io-540 and down draft cooling via NACA ducts in the turtle deck [ if you can call it that] He also had a type of flow control bump on either side of the ducts to improve the pressure recovery. I think it took a few tries for him to get it working correctly but in the end it worked fairly well I think. Jarrett ----- Original Message ----- From: "James" To: "Rotary motors in aircraft" Sent: Friday, March 10, 2006 3:21 PM Subject: [FlyRotary] Re: NACA's, Cooling and Sport Aviation Mag.. > The vortex generator article I read had a > photograph with the NACA scoop on top much like > a velocity... must have been a velocity. > Regards; James Freeman > > al p Wick wrote: > >>I have totally stock Naca on Cozy. Just added >>the vortex generators as >>John describes (I think it's 40 deg included >>angle). >> >> I found air flowed in wrong direction often >> upon takeoff. It would both >>take time and playing around with aircraft >>attitude to get it to flow in >>correct direction. There after, it did ok. >>Adding erics vg's increased >>total pressure differential and totally >>eliminated that initial flow >>problem. In hind sight, this makes sense. The >>cozy has long flat bottom. >>NACA at rear of craft. Thick boundary layer at >>that location. So the vg's >>break thru the boundary layer allowing the NACA >>to do it's thing. I >>measure air pressure differential with PC and >>atmospheric sensors. Log >>info every few moments. >> >>I have huge safety margin with my cooling. >>Lucked out and learned from >>others. Didn't allow myself to make any design >>assumptions. >> >> >>-al wick >>Artificial intelligence in cockpit, Cozy IV >>powered by stock Subaru 2.5 >>N9032U 200+ hours on engine/airframe from >>Portland, Oregon >>Prop construct, Subaru install, Risk assessment, >>Glass panel design info: >>http://www.maddyhome.com/canardpages/pages/alwick/index.html >> >> >> >>On Fri, 10 Mar 2006 14:50:55 -0500 john slade >> >>writes: >> >>>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/ >>> >>>-- >>>Homepage: http://www.flyrotary.com/ >>>Archive and UnSub: >>>http://mail.lancaironline.net/lists/flyrotary/ >>> >>> >>> >> >> >>-al wick >>Artificial intelligence in cockpit, Cozy IV >>powered by stock Subaru 2.5 >>N9032U 200+ hours on engine/airframe from >>Portland, Oregon >>Prop construct, Subaru install, Risk assessment, >>Glass panel design info: >>http://www.maddyhome.com/canardpages/pages/alwick/index.html >> >>-- >>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/ > > > -- > No virus found in this incoming message. > Checked by AVG Free Edition. > Version: 7.1.375 / Virus Database: 268.2.1/278 - > Release Date: 3/9/2006 >