X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from [24.25.9.101] (HELO ms-smtp-02-eri0.southeast.rr.com) by logan.com (CommuniGate Pro SMTP 5.0.8) with ESMTP id 1033366 for flyrotary@lancaironline.net; Mon, 13 Mar 2006 23:22:22 -0500 Received-SPF: pass receiver=logan.com; client-ip=24.25.9.101; envelope-from=eanderson@carolina.rr.com Received: from edward2 (cpe-024-074-025-165.carolina.res.rr.com [24.74.25.165]) by ms-smtp-02-eri0.southeast.rr.com (8.13.4/8.13.4) with SMTP id k2E4LX5k001509 for ; Mon, 13 Mar 2006 23:21:34 -0500 (EST) Message-ID: <000301c6471e$c8750120$2402a8c0@edward2> From: "Ed Anderson" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: finding a radiator Date: Mon, 13 Mar 2006 23:21:35 -0500 MIME-Version: 1.0 Content-Type: text/plain; format=flowed; charset="iso-8859-1"; reply-type=response Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.2180 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2180 X-Virus-Scanned: Symantec AntiVirus Scan Engine I believe I had a spreadsheet for calculating the coordinates (I did at one time). I'll see if I can find it, Chris. Ed ----- Original Message ----- From: "the mallorys" To: "Rotary motors in aircraft" Sent: Monday, March 13, 2006 9:55 PM Subject: [FlyRotary] Re: finding a radiator > Looks like there will be some experimenting in my future. > > Ed, > > Do you have any more info on the exponential horn? I would need > coordinates, formulas, drawing, or something, then I could make a trial > run of all three and see which is most efficient. > > Chris > ----- Original Message ----- > From: "Ed Anderson" > To: "Rotary motors in aircraft" > Sent: Monday, March 13, 2006 8:11 PM > Subject: [FlyRotary] Re: finding a radiator > > >>I could never find any information on the efficiency of the Wedge diffuser >>at subsonic speeds. However, you are correct about the streamline duct. >>Measure from the core forward then truncate where you have to. Here is >>the way it appears to me, approx 1/2 of the streamline ducts pressure >>recover is due to the length of the duct walls the other 1/2 is due to the >>trumpet style flair near the core. So say you completely eliminated the >>duct and just had the flair then you would get approx 42% pressure >>recovery (not terrible good). So if you could incorporate 1/2 of the duct >>length then you would be closer to a 62% pressure recovery (getting >>better). These are just rough estimates, but I have been please with the >>truncated streamline duct. >> >> There is another similar duct coordinate system call the exponential horn >> that is easier to scale for shorter duct lengths. It appears to be based >> on the same concept of the streamline of keeping the air velocity rather >> high until the a last minute flair of the duct to get pressure recovery. >> It would appear that it's efficiency would be close to the streamline and >> its ease of calculation might make it worth the effort alone. But, again >> I have not been able to find any actually data on pressure recovery. >> >> If I do another cooling duct experiment, it will be using the exponential >> horn duct just to see how it works. But, not today {:>) >> >> Ed >> >> Ed Anderson >> Rv-6A N494BW Rotary Powered >> Matthews, NC >> eanderson@carolina.rr.com >> ----- Original Message ----- >> From: "rijakits" >> To: "Rotary motors in aircraft" >> Sent: Monday, March 13, 2006 8:43 PM >> Subject: [FlyRotary] Re: finding a radiator >> >> >>> If I got the idea right, to use the Streamline you would want to sketch >>> the >>> "perfect" streamline for your radiator and then measure FROM the >>> radiator >>> towards the intake - whatever length you can do, and cut it there. >>> That will be your intake area..... >>> >>> Wedge should be simple: Whatever your opening is - constant cross-area >>> to >>> the radiator - as big a radius at the bottom near end as you can >>> justify - >>> same point top surface, start a tapper to the end of the radiator to end >>> about 1/2" above the far end and radius it down. >>> >>> Which one is better? No idea! >>> Generally I would guess streamline, but in your case it will not be >>> perfect, >>> so you might want to do some mockup from plywood/cardboard/etc. and try >>> some >>> watermanometer tests/kitchenscale on the rooftop on top of your car - >>> tests..... >>> >>> Thomas J. >>> >>> PS: PL over at the "other" site was lofting both systems together, looks >>> good but results are anyones guess.... >>> >>> ----- Original Message ----- >>> From: "the mallorys" >>> To: "Rotary motors in aircraft" >>> Sent: Monday, March 13, 2006 10:25 AM >>> Subject: [FlyRotary] Re: finding a radiator >>> >>> >>>> Dennis, >>>> >>>> You seem to be at the same point in installation as I. I'm putting the >>>> Renesis in an RV-8 using the James cowl. I'm trying to fit the >>>> radiator >>>> verticaly under the engine mount. That gives me space of about 8 1/2 >>>> by >>> 19 >>>> 1/2. Make the radiator 3.75 to 4 inches thick, and I should have >>>> enough >>>> cooling. Since I don't have about 50 inches in front of the radiator >>>> for >>>> the perfect streamlined diffuser, the question for me is which will be >>> less >>>> drag, a shorter (about 20 inches) streamline, or tipping the radiator >>>> at >>> an >>>> angle and using a wedge shape diffuser? In any case, I plan on having >>>> an >>>> exit duct also with a controllable exit. >>>> >>>> Does anyone know the answer? >>>> >>>> Chris >>>> ----- Original Message ----- >>>> From: "Ernest Christley" >>>> To: "Rotary motors in aircraft" >>>> Sent: Sunday, March 12, 2006 10:37 PM >>>> Subject: [FlyRotary] Re: finding a radiator >>>> >>>> >>>> > Dennis Haverlah wrote: >>>> > >>>> >> My question is - will the air make the 75 degree turn and flow >>>> >> through >>>> >> the fins? If not - would turning vanes below the radiator make this >>>> >> configuration possible? >>>> > >>>> > Dennis, a section in K&W book discusses this very issue. The short >>> answer >>>> > is "Yes". The long answer is that you have to be very careful how >>>> > you >>>> > design the duct face in front of the radiator. If you have their >>>> > book, >>>> > it's figure 12-12 on page 277. >>>> > >>>> > -- >>>> > This is by far the hardest lesson about freedom. It goes against >>>> > instinct, and morality, to just sit back and watch people make >>>> > mistakes. We want to help them, which means control them and their >>>> > decisions, but in doing so we actually hurt them (and ourselves)." >>>> > >>>> > >>>> > -- >>>> > 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/ >