X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from cdptpa-omtalb.mail.rr.com ([75.180.132.121] verified) by logan.com (CommuniGate Pro SMTP 5.4c3j) with ESMTP id 4960467 for flyrotary@lancaironline.net; Thu, 28 Apr 2011 09:52:30 -0400 Received-SPF: pass receiver=logan.com; client-ip=75.180.132.121; envelope-from=eanderson@carolina.rr.com Return-Path: X-Authority-Analysis: v=1.1 cv=2pE2Kh9Ye2ywHyyFZnC5ZQ1FvuPrdOtuPO5uN4ysVDU= c=1 sm=0 a=RKxS59jiEN8A:10 a=rPkcCx1H5rrOSfN0dPC7kw==:17 a=arxwEM4EAAAA:8 a=r1ClD_H3AAAA:8 a=7g1VtSJxAAAA:8 a=Ia-xEzejAAAA:8 a=G1Ac32ZXMhFZZpUyuOsA:9 a=O5orSwt95BydrplUj38A:7 a=wPNLvfGTeEIA:10 a=Qa1je4BO31QA:10 a=pGLkceISAAAA:8 a=Yll1srH9AVlzAvlj1CMA:9 a=vXdWgXmK2ITk2wBHprcA:7 a=MSl-tDqOz04A:10 a=EzXvWhQp4_cA:10 a=rPkcCx1H5rrOSfN0dPC7kw==:117 X-Cloudmark-Score: 0 X-Originating-IP: 174.110.167.5 Received: from [174.110.167.5] ([174.110.167.5:62309] helo=EdPC) by cdptpa-oedge03.mail.rr.com (envelope-from ) (ecelerity 2.2.3.46 r()) with ESMTP id 53/AE-05159-9F079BD4; Thu, 28 Apr 2011 13:51:54 +0000 Message-ID: From: "Ed Anderson" To: "Rotary motors in aircraft" References: In-Reply-To: Subject: Re: [FlyRotary] Re: Cooling Inlets Date: Thu, 28 Apr 2011 09:51:21 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0029_01CC0589.D43B0D40" X-Priority: 3 X-MSMail-Priority: Normal Importance: Normal X-Mailer: Microsoft Windows Live Mail 14.0.8117.416 X-MimeOLE: Produced By Microsoft MimeOLE V14.0.8117.416 This is a multi-part message in MIME format. ------=_NextPart_000_0029_01CC0589.D43B0D40 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Great to hear, Tracy. All of the studies I have read indicates anything you can do to prevent = flow separation near the inlet (which you undoubtedly had at anything = off straight and level with those tubes) greatly aids cooling. =20 The studies say that anytime you have a disturbed/(turbulent) area of = air impinging on an area of your radiator face you do not get good = pressure recovery from disturbed air - this in turn can cause that area = impacted to suffer a 20% degradation of cooling effectiveness and also = increased drag. The further upstream from the core the disturbance = occurs the larger the affected area of the core. So your enhanced pressure recovery with the new inlets is likely largely = due to the better control of the entering airflow and the reduction of = any separation caused by the sharp ages of the tubes. =20 Also looks great. I noticed the inlets appears to have a removable cover = -- I presume this is so you can remove the inlet cover in order to = remove the cowl (or for further experimentation {:>)?) Ed Edward L. Anderson Anderson Electronic Enterprises LLC 305 Reefton Road Weddington, NC 28104 http://www.andersonee.com http://www.eicommander.com From: Tracy=20 Sent: Thursday, April 28, 2011 9:07 AM To: Rotary motors in aircraft=20 Subject: [FlyRotary] Re: Cooling Inlets Finally got around to finishing my cooling inlets. (pictures attached) = Up until now they were simply round pipes sticking out of the cowl. = The pipes are still there but they have properly shaped bellmouths on = them. The shape and contours were derived from a NASA contractor = report (NASA_CR3485) that you can find via Google. Lots of math & = formulas in it but I just copied the best performing inlet picture of = the contour. Apparently there is an optimum radius for the inner and = outer lip of the inlet. There was no change to the inlet diameters of = 5.25" on water cooler and 4.75" on oil cooler. The simple pipes performed adequately in level flight at moderate cruise = settings even on hot days but oil temps would quickly hit redline at = high power level flight and in climb. =20 The significant change with the new inlet shape is that they appear to = capture off-axis air flow (like in climb and swirling flow induced by = prop at high power) MUCH better than the simple pipes. First flight = test was on a 94 deg. F day and I could not get the oil temp above 200 = degrees in a max power climb. They may have gone higher if the air = temperature remained constant but at 3500 fpm the rapidly decreasing OAT = kept the temps well under redline (210 deg F). I have an air pressure instrument reading the pressure in front of the = oil cooler and was amazed at the pressure recovered from the prop wash. = At 130 MPH the pressure would almost double when the throttle was = advanced to WOT. That did not happen nearly as much with the simple = pipes. =20 These inlets ROCK! Tracy Crook -------------------------------------------------------------------------= ------- -- Homepage: http://www.flyrotary.com/ Archive and UnSub: = http://mail.lancaironline.net:81/lists/flyrotary/List.html ------=_NextPart_000_0029_01CC0589.D43B0D40 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Great to hear, Tracy.
 
All of the studies I have read =  indicates=20 anything you can do to prevent flow separation near the inlet (which you = undoubtedly had at anything off straight and level with those tubes) = greatly=20 aids cooling. 
 
The studies say that anytime you have a=20 disturbed/(turbulent) area of air impinging on an area of your radiator = face you=20 do not get good pressure recovery from disturbed air - this in turn = can=20 cause that area impacted  to  suffer a 20% degradation of = cooling=20 effectiveness and also increased drag.  The further = upstream from=20 the core the disturbance occurs the larger the affected area of the=20 core.
 
So your enhanced pressure recovery with the new = inlets is=20 likely largely due to the better control of the entering airflow and the = reduction of any separation caused by the sharp ages of the tubes.  =
 
Also looks great. I noticed the inlets appears = to have a=20 removable cover -- I presume this is so you can remove the inlet=20 cover in order to remove the cowl (or for further experimentation=20 {:>)?)
 
Ed
 
Edward L. Anderson
Anderson Electronic = Enterprises=20 LLC
305 Reefton Road
Weddington, NC 28104
http://www.andersonee.com
http://www.eicommander.com
 
 

From: Tracy
Sent: Thursday, April 28, 2011 9:07 AM
Subject: [FlyRotary] Re: Cooling Inlets

Finally got=20 around to finishing my cooling inlets. (pictures attached)  Up = until now=20 they were simply round pipes sticking out of the cowl.   The = pipes are=20 still there but they have properly shaped bellmouths on = them.   The=20 shape and contours were derived from a NASA contractor report = (NASA_CR3485) that=20 you can find via Google.  Lots of math & formulas in it but I = just=20 copied the best performing inlet picture of the contour.   = Apparently=20 there is an optimum radius for the inner and outer lip of the = inlet.  =20 There was no change to the inlet diameters of 5.25" on water cooler and = 4.75" on=20 oil cooler.

The simple pipes performed adequately in level flight = at=20 moderate cruise settings even on hot days but oil temps would quickly = hit=20 redline at high power level flight and in climb. 

The = significant=20 change with the new inlet shape is that they appear to capture off-axis = air=20 flow  (like in climb and swirling flow  induced by prop at = high=20 power)  MUCH better than the simple pipes.    First = flight test=20 was on a 94 deg. F day and I could not get the oil temp above 200 = degrees in a=20 max power climb.    They may have gone higher if the air = temperature=20 remained constant but at 3500 fpm the rapidly decreasing OAT kept the = temps well=20 under redline (210 deg F).

I have an air pressure instrument = reading the=20 pressure in front of the oil cooler and was amazed at the pressure = recovered=20 from the prop wash.  At 130 MPH the pressure would almost double = when the=20 throttle was advanced to WOT.   That did not happen nearly as much = with the=20 simple pipes.  

These inlets ROCK!

Tracy=20 Crook

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Homepage:  http://www.flyrotary.com/
Archive and=20 UnSub:  =20 http://mail.lancaironline.net:81/lists/flyrotary/List.html
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