X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Sat, 28 Mar 2009 21:36:19 -0400 Message-ID: X-Original-Return-Path: Received: from web36904.mail.mud.yahoo.com ([209.191.85.72] verified) by logan.com (CommuniGate Pro SMTP 5.2.13) with SMTP id 3561836 for lml@lancaironline.net; Fri, 27 Mar 2009 11:36:21 -0400 Received-SPF: none receiver=logan.com; client-ip=209.191.85.72; envelope-from=chris_zavatson@yahoo.com Received: (qmail 14803 invoked by uid 60001); 27 Mar 2009 15:35:44 -0000 DomainKey-Signature:a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=Message-ID:X-YMail-OSG:Received:X-Mailer:Date:From:Subject:To:MIME-Version:Content-Type; b=06F7nlyGkljMF1SrV4Z1RIlfE1Gs3K+bqeFUf/yicp+QcjVGls6bWTbG6NEz7QsMNF2wbOVN/uT1nNeC5KkJYBMQ8/twGz3fTOj/B5TOmxdSKAgxGXt26Zd369AXe80CVMvzXsVLj9LK2bbDs7r4Dnlb1G8G/jGXNl3a+rbkgLc=; X-Original-Message-ID: <285106.9457.qm@web36904.mail.mud.yahoo.com> X-YMail-OSG: HoKlzoQVM1nIWJba1Vmm9r30tzTgWihvxaThnLgEd.iqWk2tehMR65oeZBS13cSgI0gr8gWYs0BAIAlmnTnp_QEP6DZklfiP5suPFPmEYXPSxxf7vcY3LYu_6NKcvu6gP0npKWZNdByWaxCys95iOlWjLOXCtmRuy_owAQrYSkIOQ.JdJBR58ogDNQASPTWya04bLnuMLX_NfBpjpWKwVaJ85s7lUarpnxGmN1TryqbT Received: from [76.246.40.52] by web36904.mail.mud.yahoo.com via HTTP; Fri, 27 Mar 2009 08:35:44 PDT X-Mailer: YahooMailRC/1277.32 YahooMailWebService/0.7.289.1 X-Original-Date: Fri, 27 Mar 2009 08:35:44 -0700 (PDT) From: Chris Zavatson Subject: Re: [LML] Poor Slow-flight Cooling X-Original-To: Lancair Mailing List MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="0-2120533150-1238168144=:9457" --0-2120533150-1238168144=:9457 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable Bill,=0A-one possibility=0AThe air coming in from your 3 inch duct may actu= ally be leaving through the NACA scoop during slow flight.=A0=A0NACA scoops= =A0are somewhat sensitive to orientation to the airstream and while in slow= flight the orientation may be off far enough that the NACA scoop is no lon= ger effective.=A0 Two parallel sources will fight each other if the pressur= es aren't well balanced.=A0 In this case, if the NACA scoop pressure drops = all of a sudden, you=A0would see=A0a flow reversal.=A0 =0AIf you measure=A0= the pressure ahead of the cooler as you slow down,=A0you should be able to = see this=A0transition occur.=0A=0A=A0=0AChris Zavatson=0AN91CZ=0A360std=0Aw= ww.N91CZ.com=0A=0A=0A --0-2120533150-1238168144=:9457 Content-Type: text/html; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable
Bill,
=0A
-one possibility
=0A
The air coming i= n from your 3 inch duct may actually be leaving through the NACA scoop duri= ng slow flight.  NACA scoops are somewhat sensitive to orien= tation to the airstream and while in slow flight the orientation may be off= far enough that the NACA scoop is no longer effective.  Two parallel = sources will fight each other if the pressures aren't well balanced.  = In this case, if the NACA scoop pressure drops all of a sudden, you wo= uld see a flow reversal. 
=0A
If you measure the p= ressure ahead of the cooler as you slow down, you should be able to se= e this transition occur.
=0A

 
=0A
Chris Zavatson=
=0A
N91CZ
=0A
360std
=0A

=0A=0A --0-2120533150-1238168144=:9457--