X-Virus-Scanned: clean according to Sophos on Logan.com X-SpamCatcher-Score: 1 [X] Return-Path: Received: from cdptpa-omtalb.mail.rr.com ([75.180.132.122] verified) by logan.com (CommuniGate Pro SMTP 5.3.9) with ESMTP id 4499663 for flyrotary@lancaironline.net; Sat, 09 Oct 2010 13:58:55 -0400 Received-SPF: pass receiver=logan.com; client-ip=75.180.132.122; envelope-from=eanderson@carolina.rr.com Return-Path: X-Authority-Analysis: v=1.1 cv=R3xZCyK5Rzzq4RgmEA8QIQ3hFZTdsD3z+kRPUs1QTwQ= c=1 sm=0 a=EYsvJn3TNJ4A:10 a=rPkcCx1H5rrOSfN0dPC7kw==:17 a=ayC55rCoAAAA:8 a=arxwEM4EAAAA:8 a=r1ClD_H3AAAA:8 a=DFrU5x1stA3VsxeOHDQA:9 a=8D7__Z1-CLHGTuJ_Kar6NSzL8xkA:4 a=wPNLvfGTeEIA:10 a=pGLkceISAAAA:8 a=E93lBu2AAAAA:8 a=e4K-e5Jt0Dn7xel4LRQA:9 a=d9eC-pmbj5f9KEfWW2MA:7 a=EpBQ1ki8HeO0aJRl64a-XCElSXcA:4 a=MSl-tDqOz04A:10 a=hO30gm18fF0A:10 a=x6VBWS02HY8A:10 a=d1n8sfsg-lQA:10 a=NWVoK91CQyQA:10 a=rPkcCx1H5rrOSfN0dPC7kw==:117 X-Cloudmark-Score: 0 X-Originating-IP: 174.110.167.5 Received: from [174.110.167.5] ([174.110.167.5:63560] helo=EdPC) by cdptpa-oedge01.mail.rr.com (envelope-from ) (ecelerity 2.2.3.46 r()) with ESMTP id 97/D1-06710-B3DA0BC4; Sat, 09 Oct 2010 17:58:19 +0000 Message-ID: <0223597E5744402AB6A06FFD32F94FC2@EdPC> From: "Ed Anderson" To: "Rotary motors in aircraft" , "Panzera Pat" Subject: Fw: [FlyRotary] Effective Prop Pitch Calculations Date: Sat, 9 Oct 2010 13:58:05 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0029_01CB67B9.FEC4EB80" X-Priority: 3 X-MSMail-Priority: Normal Importance: Normal X-Mailer: Microsoft Windows Live Mail 14.0.8117.416 X-MimeOLE: Produced By Microsoft MimeOLE V14.0.8117.416 This is a multi-part message in MIME format. ------=_NextPart_000_0029_01CB67B9.FEC4EB80 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable From Pat - appears my problem is not "slippage" but negative Thrust - = well, negative thrust does not sound very positive to me. Now If I had = it installed as a pusher prop would I pick up 4 MPH in airspeed - with = the negative thrust now in the pushing direction {:>) Ed From: Pat Panzera=20 Sent: Saturday, October 09, 2010 1:45 PM To: eanderson@carolina.rr.com=20 Subject: Re: [FlyRotary] Effective Prop Pitch Calculations Please forward this thought for me: No slippage, your root section is creating negative thrust since it's = not pitched steep enough.=20 On Sat, Oct 9, 2010 at 10:16 AM, Ed Anderson = wrote: I used the equation that Lipps mentions in the article in CONTACT! to = Calculate "Effective Pitch" of my 74x88 prop. His equation (with some = clarifying annotations) is=20 Effective Pitch ( % ) =3D TAS (mph) *1056/RPM(Props' RPM not engine) EF =3D 168*1056/2105 =3D 84.27 effective pitch=20 Since my Props pitch is suppose to be 88" could this mean I have a bit = of "Slippage"? Actually, I was impressed that the calculation came out = as close as it did - within 4% of its 88" of pitch. =20 Thanks Pat Ed Edward L. Anderson Anderson Electronic Enterprises LLC 305 Reefton Road Weddington, NC 28104 http://www.andersonee.com http://www.eicommander.com ------=_NextPart_000_0029_01CB67B9.FEC4EB80 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
From Pat - appears my problem is not "slippage" = but=20 negative Thrust - well,  negative thrust does not sound very = positive to=20 me.  Now If I had it installed as a pusher prop would I pick up 4 = MPH in=20 airspeed - with the negative thrust now in the pushing direction=20 {:>)
 
Ed

From: Pat Panzera
Sent: Saturday, October 09, 2010 1:45 PM
To: eanderson@carolina.rr.com =
Subject: Re: [FlyRotary] Effective Prop Pitch=20 Calculations

Please forward this thought for me:

No slippage, your root section is creating negative = thrust since=20 it's not pitched steep enough.=20



On Sat, Oct 9, 2010 at 10:16 AM, Ed Anderson = <eanderson@carolina.rr.com&g= t;=20 wrote:
I used the equation that Lipps mentions in the = article=20 in CONTACT! to Calculate "Effective Pitch" of my 74x88 prop.  His = equation (with some clarifying annotations) is
 
Effective Pitch ( % ) =3D TAS (mph) = *1056/RPM(Props' RPM=20 not engine)
 
EF =3D 168*1056/2105 =3D 84.27 effective pitch =
 
Since my Props pitch is suppose to be 88" = could this=20 mean I have a bit of "Slippage"?  Actually, I was impressed that = the=20 calculation came out as close as it did - within 4% of its 88" of = pitch. =20
 
Thanks Pat
 
Ed
 
 
Edward L. Anderson
Anderson Electronic = Enterprises=20 LLC
305 Reefton Road
Weddington, NC 28104
http://www.andersonee.com
http://www.eicommander.com

------=_NextPart_000_0029_01CB67B9.FEC4EB80--