X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mail-ww0-f42.google.com ([74.125.82.42] verified) by logan.com (CommuniGate Pro SMTP 5.4c3j) with ESMTPS id 4960656 for flyrotary@lancaironline.net; Thu, 28 Apr 2011 12:00:08 -0400 Received-SPF: pass receiver=logan.com; client-ip=74.125.82.42; envelope-from=rwstracy@gmail.com Received: by wwk4 with SMTP id 4so4522825wwk.1 for ; Thu, 28 Apr 2011 08:59:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:in-reply-to:references:date :message-id:subject:from:to:content-type; bh=jDR1ZZ37cv4eI5Jx1VqEvRIdurxqq+CI2la7DXvNjkY=; b=HHj3YgkvnDF9cKmcFX7SLvMYDRvE5UOpdw8VtPdfbOqwGSywix/f9zo90hz6P5iYWy 0VOtgoxgRxel0PXcYTOku+eV+bJ4k5PKq66HYO0voKspbyu4AfvCQfRh5lrwiCpERH// YB1y1NSODa4X3fNDZPSR4RBNTUVQVkbmrXKOY= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; b=ZM4jdCK50xHnxtww9PdUNbbhG91AfkBaf7BVqvCaRO14AlZXgbN6XwrKqe95JlQ0Mr lxisXYMJaeJqQhYyeMR4478e+AlhmUG05Z3GTKXFfDEnX0biszE7743QjWoo1jL/FiFL WG4YqNgtwzQQgjUiGU8fxfzqJHh9SzkZpPCnA= MIME-Version: 1.0 Received: by 10.216.221.32 with SMTP id q32mr571669wep.77.1304006371190; Thu, 28 Apr 2011 08:59:31 -0700 (PDT) Received: by 10.216.190.132 with HTTP; Thu, 28 Apr 2011 08:59:31 -0700 (PDT) In-Reply-To: References: Date: Thu, 28 Apr 2011 11:59:31 -0400 Message-ID: Subject: Re: [FlyRotary] Re: Cooling Inlets From: Tracy To: Rotary motors in aircraft Content-Type: multipart/alternative; boundary=0016e65b646a8a268c04a1fca469 --0016e65b646a8a268c04a1fca469 Content-Type: text/plain; charset=ISO-8859-1 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. 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 Thanks Ed, I agree, that looks like the main factor. The inlets were made in 3 steps/pieces, each one bonded to the others as I went so its all one piece that slips tightly over the OD of the inlet pipe, sweeps back to fair into the cowl contours and then secured with a couple of screws into nut-plates in the cowl. Mostly made from carbon fiber to keep it light. The inlet lip was the interesting part to make. I made a tool of aluminum sheet the same shape as a cutaway drawing of the lip, mounted that in the lathe toolpost, chucked up a 9" square x 2" thick piece of urethane foam using a piece of all-thread & plywood washers. Set the 'tool' for the proper ID of the inlet pipe and then machined the inlet shape into the foam to form a female mold. Painted the foam mold with melted paraffin for a smooth finish and mold release then laid up the carbon fiber in the mold. Looked like a part out of a machine when taken out and trimmed. Only snag is that removing paraffin residue from finished part is critical. There are several fish-eye areas in the paint that will need to be sanded out & repainted. Tracy On Thu, Apr 28, 2011 at 9:51 AM, Ed Anderson wrote: > 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. > > 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. > > 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 > *Sent:* Thursday, April 28, 2011 9:07 AM > *To:* Rotary motors in aircraft > *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. > > 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. > > These inlets ROCK! > > Tracy Crook > > > ------------------------------ > > -- > Homepage: http://www.flyrotary.com/ > Archive and UnSub: > http://mail.lancaironline.net:81/lists/flyrotary/List.html > > --0016e65b646a8a268c04a1fca469 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable
So your enhanced pressure recovery with the new i= nlets is=20 likely largely due to the better control of the entering airflow and the=20 reduction of any separation caused by the sharp ages of the tubes.=A0=20
=A0
Also looks great. I noticed the inlets appears to= have a=20 removable cover -- I presume this is so you can remove=A0the inlet=20 cover=A0in order to remove the cowl (or for further experimentation=20 {:>)?)
=A0
Ed

Thanks Ed,
I agree, that looks like = the main factor.
=A0=A0
The inlets were made in 3 steps/pieces, each= one bonded to the others as I went so its all one piece that slips tightly= over the OD of the inlet pipe, sweeps back to fair into the cowl contours = and then secured with a couple of screws into nut-plates in the cowl.=A0=A0= Mostly made from carbon fiber to keep it light.

The inlet lip was the interesting part to make.=A0 I made a tool of alu= minum sheet the same shape as a cutaway drawing of the lip, mounted that in= the lathe toolpost, chucked up a 9" square x 2" thick piece of u= rethane foam using a piece of all-thread & plywood washers.=A0 Set the = 'tool' for the proper ID of the inlet pipe and then machined the in= let shape into the foam to form a female mold.=A0 Painted the foam mold wit= h melted paraffin for a smooth finish and mold release then laid up the car= bon fiber in the mold.=A0=A0 Looked like a part out of a machine when=A0 ta= ken out and trimmed.=A0=A0 Only snag is that removing paraffin residue from= finished part is critical.=A0 There are several fish-eye areas in the pain= t that will need to be sanded out & repainted.

Tracy


On Thu, Apr 28= , 2011 at 9:51 AM, Ed Anderson <eanderson@carolina.rr.com> wrote:
<= blockquote class=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;border-left:1px= #ccc solid;padding-left:1ex;">
Great to hear, Tracy.
=A0
All of=A0the studies I have read =A0indicates=20 anything you can do to prevent flow separation near the inlet (which you=20 undoubtedly had at anything off straight and level with those tubes) greatl= y=20 aids cooling.=A0
=A0
The studies say that anytime you have a=20 disturbed/(turbulent) area of air impinging on an area of your radiator fac= e you=20 do not get good pressure recovery from disturbed air -=A0this in turn can= =20 cause=A0that area impacted=A0 to =A0suffer a 20% degradation of cooling=20 effectiveness and also=A0increased drag.=A0 The further upstream=A0from=20 the core the disturbance occurs the larger the affected area of the=20 core.
=A0
So your enhanced pressure recovery with the new i= nlets is=20 likely largely due to the better control of the entering airflow and the=20 reduction of any separation caused by the sharp ages of the tubes.=A0=20
=A0
Also looks great. I noticed the inlets appears to= have a=20 removable cover -- I presume this is so you can remove=A0the inlet=20 cover=A0in order to remove the cowl (or for further experimentation=20 {:>)?)
=A0
Ed
=A0
Edward L. Anderson
Anderson Electronic Enterpr= ises=20 LLC
305 Reefton Road
Weddington, NC 28104
http://www.andersonee.com
http://www.eicommander.com
=A0
=A0

Sent: Thursday, April 28, 2011 9:07 AM
To: Rotary motors in aircraft <= /div>
Subject: [FlyRotary] Re: Cooling Inlets
=

= Finally got=20 around to finishing my cooling inlets. (pictures attached)=A0 Up until now= =20 they were simply round pipes sticking out of the cowl.=A0=A0 The pipes are= =20 still there but they have properly shaped bellmouths on them.=A0=A0 The=20 shape and contours were derived from a NASA contractor report (NASA_CR3485)= that=20 you can find via Google.=A0 Lots of math & formulas in it but I just=20 copied the best performing inlet picture of the contour.=A0=A0 Apparently= =20 there is an optimum radius for the inner and outer lip of the inlet.=A0=A0= =20 There was no change to the inlet diameters of 5.25" on water cooler an= d 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.=A0

The significant= =20 change with the new inlet shape is that they appear to capture off-axis air= =20 flow=A0 (like in climb and swirling flow=A0 induced by prop at high=20 power)=A0 MUCH better than the simple pipes. =A0=A0 First flight test=20 was on a 94 deg. F day and I could not get the oil temp above 200 degrees i= n a=20 max power climb. =A0=A0 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 recovere= d=20 from the prop wash.=A0 At 130 MPH the pressure would almost double when the= =20 throttle was advanced to WOT. =A0 That did not happen nearly as much with t= he=20 simple pipes.=A0=A0

These inlets ROCK!

Tracy=20 Crook

--
Homepage:=A0 http://www.flyrotary.com/
Archive and=20 UnSub:=A0=A0=20 http://mail.lancaironline.net:81/lists/flyrotary/List.html


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