X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mail-qy0-f203.google.com ([209.85.221.203] verified) by logan.com (CommuniGate Pro SMTP 5.2.16) with ESMTP id 3859295 for flyrotary@lancaironline.net; Sat, 19 Sep 2009 00:04:55 -0400 Received-SPF: pass receiver=logan.com; client-ip=209.85.221.203; envelope-from=rwstracy@gmail.com Received: by qyk41 with SMTP id 41so1312347qyk.25 for ; Fri, 18 Sep 2009 21:04:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:sender:received:in-reply-to :references:date:x-google-sender-auth:message-id:subject:from:to :content-type; bh=Vwpfr1fpOkAdg18M8NUhW1miww+tSupnNmFpj0KkfWg=; b=XQ4O3VB2+X8IXFHj7lPDY2LNG7H5+X/mZRCfA4rPw1m/fHH490qQucZmzdGai/UzZp UdQJFd6BO6XM3Wop18CXVp0AQG3mdtuadoGG3qNtPBS+CKgGiNESXs3Q6RsOOGrINdDd s7H0a/78EPuqk7HVilHG9sdd8vErVQLzHatvc= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:content-type; b=G+HwkqHXki8pHRyZTtD0QkFNYjUky7sycFULzfgdoNykqwyuATaW5I1iYkzyPCuMJ2 mVoHgc/Inhe4JRtQDijVgpcgLwha/8jwT/jpe7CVam66WC0HeUzhRkI1J6A/0wxwWz+0 BYMOS0A80QsyOub4iQGVSK6zCycEklSfzDM2M= MIME-Version: 1.0 Sender: rwstracy@gmail.com Received: by 10.224.103.75 with SMTP id j11mr2028155qao.46.1253333060515; Fri, 18 Sep 2009 21:04:20 -0700 (PDT) In-Reply-To: References: Date: Sat, 19 Sep 2009 00:04:20 -0400 X-Google-Sender-Auth: 0325d4ef6187c3fa Message-ID: <1b4b137c0909182104v670898b5v7bd3276b7b5d6146@mail.gmail.com> Subject: Re: [FlyRotary] Re: Re RV-8 cooling test From: Tracy Crook To: Rotary motors in aircraft Content-Type: multipart/alternative; boundary=000feaf0634cdb7a330473e65722 --000feaf0634cdb7a330473e65722 Content-Type: text/plain; charset=ISO-8859-1 You could just try duct taping a bent tab at the leading edge of the hole to act as a deflector and create low pressure at the hole. Then go fly it again. Quick and dirty. Wait a minute! Who am I to give advice to the master of all things rotary? Mike Wills RV-4 N144MW Not a bad idea, probably should have tried that but sometimes you just can't resist skipping ahead a couple of steps. If I really was the master, I wouldn't be sawing big holes in my nicely painted cowl :>) Tracy On Fri, Sep 18, 2009 at 10:20 PM, Mike Wills wrote: > You could just try duct taping a bent tab at the leading edge of the hole > to act as a deflector and create low pressure at the hole. Then go fly it > again. Quick and dirty. > > Wait a minute! Who am I to give advice to the master of all things rotary? > > Mike Wills > RV-4 N144MW > > ----- Original Message ----- > *From:* Tracy Crook > *To:* Rotary motors in aircraft > *Sent:* Friday, September 18, 2009 5:00 PM > *Subject:* [FlyRotary] Re: Re RV-8 cooling test > > Because it looked easy to modify the bottom cowl outlet on the RV-8 to a > cowl flap configuration I decided to try that before installing some louvers > in the same area. Attached is a picture of the cowl after I cut out the > area that would form the bottom of cowl flap. > > Couldn't resist the urge to test fly the plane with that big gaping hole in > the bottom. I was thinking that it would show if it was the small size of > the stock opening that was causing the problem or if aerodynamic factors > dominated. > > The 'big hole' outlet ran about 10 degrees cooler than stock which was not > nearly the improvement I'm looking for so I can't believe that the louvers > would work in this location. Back to working on the cowl flap in the hopes > that the low pressure area behind it will extract a lot more air. I don't > have a warm fuzzy about it though. After this (if it doesn't work) I'll > try a bluff body extractor vent as described by some CAFE Foundation > reports. > > Just as a point of reference, I have about 35 sq in of inlet area and 52 > inches of outlet area with the stock cooling outlet. Now I know that the > inlet area is more than large enough (from the cowl off flight test) and the > 52 sq In outlet should be enough but I think the pressure is too high under > the fuselage where the outlet is. > > Tracy > > On Thu, Sep 17, 2009 at 6:13 PM, wrote: > >> Thanks for that. >> I'm making my radiator chin scoop right now. >> I made a 'buck' out of 2 part pour foam, then cut & sanded to shape. After >> laying up the part, and removing it, I began to remove the edges. Good thing >> I made it too deep. Now you guys have revisited the Exit/Inlet relationship >> issue. >> A little time with a ruler, some quick math, and some trimming is leading >> me right to the reccomended 30% bigger exit area than inlet area for the >> radiator. I was going to use Van's original exit, but now I'm adding about >> 1/2" more depth. >> My oil cooler exit area is really over sized. It is kept separate. The >> right cowl inlet is ducted to the oil cooler, then exhausted straight out >> the right side thru louvers. >> The left cowl inlet has not been made yet. It will feed air to the >> turbocharger and provide surface cooling air for the exhaust system and fuel >> injectors. If that chokes the air exit at the bottom, I'll have to make a >> left side hot air exit as well. >> Tracy, your comment about overheated coils and alternator has me thinking >> about blast tubes? >> Scott > > > ------------------------------ > > -- > Homepage: http://www.flyrotary.com/ > Archive and UnSub: > http://mail.lancaironline.net:81/lists/flyrotary/List.html > > --000feaf0634cdb7a330473e65722 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable
You could just try duct taping a bent = tab at the=20 leading edge of the hole to act as a deflector and create low pressure at t= he=20 hole. Then go fly it again. Quick and dirty.
=A0
=A0Wait a minute!=A0Who am I to give a= dvice=20 to the master of all things rotary?
=A0
Mike Wills
RV-4 N144MW


N= ot a bad idea, probably should have tried that but sometimes you just can&#= 39;t resist skipping
ahead a couple of steps.
=A0 If I really was th= e master, I wouldn't be sawing big holes in my nicely painted cowl :>= ;)

Tracy

On Fri, Sep 18, 2009 at 10:20 P= M, Mike Wills <rv-= 4mike@cox.net> wrote:
You could just try duct taping a bent = tab at the=20 leading edge of the hole to act as a deflector and create low pressure at t= he=20 hole. Then go fly it again. Quick and dirty.
=A0
=A0Wait a minute!=A0Who am I to give a= dvice=20 to the master of all things rotary?
=A0
Mike Wills
RV-4 N144MW=A0
----- Original Message -----
From:=20 Tracy=20 Crook
Sent: Frid= ay, September 18, 2009 5:00=20 PM
Subject: [FlyRotary] Re: Re RV-8 c= ooling=20 test

Because it looked easy to modify t= he bottom cowl outlet on the=20 RV-8 to a cowl flap configuration I decided to try that before installing= some=20 louvers in the same area.=A0 Attached is a picture of the cowl after I cu= t=20 out the area that would form the bottom of cowl flap.=A0

Couldn&#= 39;t=20 resist the urge to test fly the plane with that big gaping hole in the bo= ttom.=20 =A0 I was thinking that it would show if it was the small size of the sto= ck=20 opening that was causing the problem or if aerodynamic factors=20 dominated.

The 'big hole' outlet ran about 10 degrees cool= er than stock=20 which was not nearly the improvement I'm looking for so I can't b= elieve that=20 the louvers would work in this location.=A0 Back to working on the cowl= =20 flap in the hopes that the low pressure area behind it will extract a lot= more=20 air. =A0 I don't have a warm fuzzy about it though. =A0 After this (i= f=20 it doesn't work) I'll try a bluff body extractor vent as describe= d by some=20 CAFE Foundation reports.

Just as a point of reference, I ha= ve about 35=20 sq in of inlet area and 52 inches of outlet area with the stock cooling= =20 outlet. =A0 Now I know that the inlet area is more than large enough (fro= m=20 the cowl off flight test) and the 52 sq In outlet should be enough but I = think=20 the pressure is too high under the fuselage where the outlet=20 is.

Tracy

On Thu, Sep 17, 2009 at 6:13 PM, <SHIPCHIEF@a= ol.com> wrote:
Thanks for that.=
I'm=20 making my radiator chin scoop right now.
I made a 'buck' out= of 2 part=20 pour foam, then cut & sanded to shape. After laying up the part, an= d=20 removing it, I began to remove the edges. Good thing I made it too deep= . Now=20 you guys have revisited the Exit/Inlet relationship issue.
A little = time=20 with a ruler, some quick math, and some trimming is leading me right to= the=20 reccomended 30% bigger exit area than inlet area for the radiator. I wa= s=20 going to use Van's original exit, but now I'm adding about 1/2&= quot; more=20 depth.
My oil cooler exit area is really over sized. It is kept sepa= rate.=20 The right cowl inlet is ducted to the oil cooler, then exhausted straig= ht=20 out the right side thru louvers.
The left cowl inlet has not been ma= de=20 yet. It will feed air to the turbocharger and provide surface cooling a= ir=20 for the exhaust system and fuel injectors. If that chokes the air exit = at=20 the bottom, I'll have to make a left side hot air exit as well. Tracy,=20 your comment about overheated coils and alternator has me thinking abou= t=20 blast tubes?
Scott

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

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