X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from cdptpa-omtalb.mail.rr.com ([75.180.132.120] verified) by logan.com (CommuniGate Pro SMTP 5.1.12) with ESMTP id 2394282 for flyrotary@lancaironline.net; Thu, 18 Oct 2007 15:30:03 -0400 Received-SPF: pass receiver=logan.com; client-ip=75.180.132.120; envelope-from=eanderson@carolina.rr.com Received: from edward2 ([24.74.103.61]) by cdptpa-omta01.mail.rr.com with SMTP id <20071018192925.VWWY6760.cdptpa-omta01.mail.rr.com@edward2> for ; Thu, 18 Oct 2007 19:29:25 +0000 Message-ID: <002001c811bd$4c35e230$2402a8c0@edward2> From: "Ed Anderson" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Math Help Date: Thu, 18 Oct 2007 15:30:10 -0400 MIME-Version: 1.0 Content-Type: text/plain; format=flowed; charset="iso-8859-1"; reply-type=original Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.3138 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3138 I bow to Ron's calculation, it takes account drag as well as altitude which mine did not. Ed ----- Original Message ----- From: "Ron Springer" To: "Rotary motors in aircraft" Sent: Thursday, October 18, 2007 3:07 PM Subject: [FlyRotary] Re: Math Help > Steve, > > For a flat plate 90 deg to the flow, the drag > coefficient is about 1.17. The drag is equal to the > drag coeff. times the plate area time the dynamic > pressure. For a fixed true airspeed of 200 mph, the > dynamic pressure varies with altitude. It is 0.71 psi > at sea level and 0.52 psi at 10,000 ft. > > So, the drag force is 12.5 lbs at sea level and 9.2 > lbs at 10,000 ft. Hope that helps. > > Ron > > > --- Steve Thomas wrote: > >> Not being much of a math or engineering whiz, can >> anyone help me >> calculate the force the relative wind would put on a >> device that >> hangs in the breeze on my airplane? Assuming a 200 >> MPH airspeed, and >> a flat plate of 15 sq. inches, what would be the >> amount of force on >> the plate in pounds? >> >> Best Regards, >> >> Steve >> > ____________________________________________________________________ >> >> >> > > > -- > Homepage: http://www.flyrotary.com/ > Archive and UnSub: > http://mail.lancaironline.net:81/lists/flyrotary/List.html >