Return-Path: <13brv3@bellsouth.net> Received: from imf25aec.mail.bellsouth.net ([205.152.59.73] verified) by logan.com (CommuniGate Pro SMTP 4.2b5) with ESMTP id 164583 for flyrotary@lancaironline.net; Wed, 16 Jun 2004 08:58:21 -0400 Received: from rad ([65.6.194.9]) by imf25aec.mail.bellsouth.net (InterMail vM.5.01.06.08 201-253-122-130-108-20031117) with ESMTP id <20040616125751.TYFL8806.imf25aec.mail.bellsouth.net@rad> for ; Wed, 16 Jun 2004 08:57:51 -0400 From: "Russell Duffy" <13brv3@bellsouth.net> To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Cooling airflow Date: Wed, 16 Jun 2004 07:57:54 -0500 Message-ID: <00b801c453a1$8a57b3a0$6001a8c0@rad> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_00B9_01C45377.A181ABA0" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.4510 Importance: Normal X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1165 In-Reply-To: This is a multi-part message in MIME format. ------=_NextPart_000_00B9_01C45377.A181ABA0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Is it just the fiberglass work people are avoiding, is it the avoidance = of the unknown (surely Rusty will have a go here???) What am I missing? =20 Hi Mike, =20 Fiberglass avoidance is certainly a factor for me :-) =20 =20 In looking at a stock RV-3/4 cowl, it would appear that you could save = all kinds of drag by lopping off the cheeks, but that really doesn't work = out to be true. Everything I've heard about these teardrop shaped cheeks = suggests that they're almost a perfect shape, with virtually no drag penalty. = The main drag is the cooling airflow through them, which you can minimize if = you start archiving all of Ed's posts :-) =20 One of the most compelling reasons for getting rid of the cheeks is = simply appearance. It would let everyone know that there's something different under the cowl. The average observer would walk right past most of the rotary powered planes without having a clue. That can be good or bad I guess. =20 =20 Cheers, Rusty (hey, what's that bright object in the sky... and why isn't it raining) =20 ------=_NextPart_000_00B9_01C45377.A181ABA0 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Message

Is it just the fiberglass work people are avoiding, is = it the=20 avoidance of the unknown (surely Rusty will have a go here???) What am I = missing?

 
Hi=20 Mike,
 
Fiberglass avoidance is=20 certainly a factor for me :-) 
 
In = looking at a=20 stock RV-3/4 cowl, it would appear that you could save all kinds of = drag by=20 lopping off the cheeks, but that really doesn't work out to be = true. =20 Everything I've heard about these teardrop shaped cheeks = suggests that=20 they're almost a perfect shape, with virtually no = drag penalty.  The=20 main drag is the cooling airflow through them, which you can minimize if = you=20 start archiving all of Ed's posts :-)
 
One of = the most=20 compelling reasons for getting rid of the cheeks is simply=20 appearance.  It would let everyone know that = there's something=20 different under the cowl.  The average observer would walk = right past=20 most of the rotary powered planes without having a clue.  = That=20 can be good or bad I guess.  
 
Cheers,
Rusty = (hey, what's that=20 bright object in the sky... and why isn't it raining) =20
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