Return-Path: Received: from [65.54.169.95] (HELO hotmail.com) by logan.com (CommuniGate Pro SMTP 4.1.8) with ESMTP id 3051613 for flyrotary@lancaironline.net; Sun, 29 Feb 2004 20:58:23 -0500 Received: from mail pickup service by hotmail.com with Microsoft SMTPSVC; Sun, 29 Feb 2004 17:58:22 -0800 Received: from 67.243.77.45 by bay3-dav65.bay3.hotmail.com with DAV; Mon, 01 Mar 2004 01:58:22 +0000 X-Originating-IP: [67.243.77.45] X-Originating-Email: [kerrjb@msn.com] X-Sender: kerrjb@msn.com From: "WALTER KERR" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: PROP Free Spinning or WindMilling??? Date: Sun, 29 Feb 2004 20:58:55 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_009C_01C3FF06.D98710A0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: MSN 8.5 X-MimeOLE: Produced By MSN MimeOLE V8.50.0017.1202 Seal-Send-Time: Sun, 29 Feb 2004 20:58:58 -0500 Message-ID: X-OriginalArrivalTime: 01 Mar 2004 01:58:22.0989 (UTC) FILETIME=[AD711BD0:01C3FF30] This is a multi-part message in MIME format. ------=_NextPart_000_009C_01C3FF06.D98710A0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable At zero lift it has some parasite drag, but it's the induced drag that = dominates.=20 Hi Jim, Doesn't make better sense to me, I fell off the sled with the opening = statement that at zero lift the induced drag dominates, and I have a = degree in aero engineering :>) If I can remember back to aero 101 in = the 50's, the induced drag is a function of lift coef. squared and would = be zero at zero angle of attack. I believe the prop runs at a high = negative angle of attack when it is windmilling with load and approachs = the zero lift angle of attack when freewheeling. When the prop is loaded = or stopped, the disk theory does not apply, it only the drag of the = stick. Bernie Kerr ------=_NextPart_000_009C_01C3FF06.D98710A0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

At zero lift it has some parasite drag, but it's the induced = drag=20 that dominates.

Hi Jim,

Doesn't make better sense to me, I fell off the sled with the = opening=20 statement that at zero lift the induced drag dominates, and I have a = degree in=20 aero engineering :>) If I can remember back to aero 101 = in the=20 50's, the induced drag is a function of lift coef. squared and = would be=20 zero at zero angle of attack. I believe the prop runs at a high = negative=20 angle of attack when it is windmilling with load and approachs the = zero lift=20 angle of attack when freewheeling. When the prop is loaded or stopped, = the=20 disk theory does not apply, it only the drag of the stick.

Bernie Kerr

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