X-Virus-Scanned: clean according to Sophos on Logan.com X-SpamCatcher-Score: 1 [X] Return-Path: Sender: To: lml Date: Fri, 09 Feb 2007 18:57:12 -0500 Message-ID: X-Original-Return-Path: Received: from smtp108.sbc.mail.re2.yahoo.com ([68.142.229.97] verified) by logan.com (CommuniGate Pro SMTP 5.1.6) with SMTP id 1827354 for lml@lancaironline.net; Fri, 09 Feb 2007 18:22:28 -0500 Received-SPF: none receiver=logan.com; client-ip=68.142.229.97; envelope-from=elippse@sbcglobal.net Received: (qmail 22285 invoked from network); 9 Feb 2007 23:21:41 -0000 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=sbcglobal.net; h=Received:X-YMail-OSG:Message-ID:From:To:Subject:Date:MIME-Version:Content-Type:X-Priority:X-MSMail-Priority:X-Mailer:X-MIMEOLE; b=sK/xlmOtDp3keX0uE89vSIaDxgD8jYfC0H2YFteABldD/tCDBLBX/UUAKdh/VesC7488WVlg6jouBhy9QdqUuPtI9FCtFrJirq0kStTaAnYspitZS88epmSIgIOurmgzBgJAGuT54bZ6U7sq/W0gmOLUpdj6jXLotvB7Yo/O9PQ= ; Received: from unknown (HELO Computerroom) (elippse@sbcglobal.net@69.227.129.135 with login) by smtp108.sbc.mail.re2.yahoo.com with SMTP; 9 Feb 2007 23:21:41 -0000 X-YMail-OSG: hlj7AFUVM1nbDGeaXUCT1IrVyZEkhUVq39P8qy3yHUZFbQtOQHE5WBjs6W1KfU6buGA_PJxV0x955XdNrC.v6ED34LCG4eaW29_WTfYt0ySNzXV7x2U95CVN86Ox9_6XoeKbSavoxQwnav1rnvOXTt7yGM6ZFzSM5M2A4vmtsvpwZGO0gVluPsUDAkyy X-Original-Message-ID: <003b01c74ca1$0fbe64d0$139f0f4b@Computerroom> From: "Paul Lipps" X-Original-To: "Marv Kaye" Subject: lift X-Original-Date: Fri, 9 Feb 2007 15:15:56 -0800 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0023_01C74C5D.32657D50" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.3028 X-MIMEOLE: Produced By Microsoft MimeOLE V6.00.2900.3028 This is a multi-part message in MIME format. ------=_NextPart_000_0023_01C74C5D.32657D50 Content-Type: text/plain; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable It seems that everything I read about lift describes it in terms of = effect, not cause, i.e. Lift occurs because flow is turned downward = creating downwash. Well, what made the air turn downward? Lift occurs = when a moving flow of gas is turned by a solid object. Just how did this = solid object turn it? Citing Newton's action -reaction still does not = explain what caused the action. And to me, these explanations are not = theories in the strictest sense, they are hypotheses. Until a hypothesis = has been reduced to an actual theory, which completely describes how a = process comes about, is provable, and is accepted by the experts as the = real explanation, any hypothesis has as much validity as any other, = regardless of how bizarre it may seem, such as my "Hose&Kite" = hypothesis. The very fact that there are so many explanations put forth = on lift, each one with its own devotees, proves my point; no one really = seems to know what causes the pressure reduction. Showing all these = wonderful pressure diagrams and saying that they are what causes lift = still does not say how these pressure gradients were generated! Here's one that really gets to me: Lift=3Drho V^2 CL A / 2. That = equation implies that dynamic pressure generates lift. If so, how can it = generate 50% more lift than is available from the dynamic pressure when = operating at a CL 1.5? Or even three pounds of lift per one pound of = dynamic pressure when a wing has slats and slotted flaps and has a CL of = 3.0? Is the wing similar to a wedge that takes a linear force and = creates a much greater normal force? So, basically, all these write-ups = say one thing - nobody really knows for certain where lift comes from! ------=_NextPart_000_0023_01C74C5D.32657D50 Content-Type: text/html; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable

It seems that everything I = read about=20 lift describes it in terms of effect, not cause, i.e. = Lift occurs=20 because flow is turned downward creating downwash. Well, what = made=20 the air turn downward? Lift occurs when a moving = flow of gas=20 is turned by a=20 solid object. Just how did this solid = object turn it?=20 Citing Newton's action -reaction still does not explain what caused the=20 action. And to me, these explanations are not theories in the = strictest=20 sense, they are hypotheses. Until a hypothesis has been reduced to = an=20 actual theory, which completely describes how a process comes about, is=20 provable, and is accepted by the experts as the real = explanation, any=20 hypothesis has as much validity as any other, regardless of how bizarre = it may=20 seem, such as my "Hose&Kite" hypothesis. The very fact that there = are so=20 many explanations put forth on lift, each one with its own devotees, = proves my=20 point; no one really seems to know what causes the pressure = reduction.=20 Showing all these wonderful pressure diagrams and saying that they are = what=20 causes lift still does not say how these pressure gradients were=20 generated!

Here's one that really gets = to me:=20 Lift=3Drho V^2 CL A / 2. That equation implies that dynamic = pressure=20 generates lift. If so, how can it generate 50% more lift than is = available from=20 the dynamic pressure when operating at a CL 1.5? Or even three pounds of = lift=20 per one pound of dynamic pressure when a wing has slats and slotted = flaps and=20 has a CL of 3.0? Is the wing similar to a wedge that takes a linear = force and=20 creates a much greater normal force? So, basically, all these write-ups = say one=20 thing - nobody really knows for certain where lift comes=20 from!

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