X-Virus-Scanned: clean according to Sophos on Logan.com X-SpamCatcher-Score: 1 [X] Return-Path: Received: from cdptpa-omtalb.mail.rr.com ([75.180.132.121] verified) by logan.com (CommuniGate Pro SMTP 5.3.9) with ESMTP id 4499621 for flyrotary@lancaironline.net; Sat, 09 Oct 2010 12:40:30 -0400 Received-SPF: pass receiver=logan.com; client-ip=75.180.132.121; envelope-from=eanderson@carolina.rr.com Return-Path: X-Authority-Analysis: v=1.1 cv=ZBI6RdNETH4sDdlJjm+X1V76MXTYJ4j6p+Mc58whUtE= c=1 sm=0 a=b4O3qZVmnbMA:10 a=rPkcCx1H5rrOSfN0dPC7kw==:17 a=ayC55rCoAAAA:8 a=3oc9M9_CAAAA:8 a=FYN5-xcaAAAA:8 a=VNUe6yB6AAAA:8 a=DbNbkGwUAF9oud6IKsUA:9 a=BUprlQov2KCfwaHH9jOp0cTX1L4A:4 a=pILNOxqGKmIA:10 a=3vEh8dZAO9sA:10 a=U8Ie8EnqySEA:10 a=-HZC1ia70vQUQKLa:21 a=pZehlEO9oCKFdySa:21 a=pGLkceISAAAA:8 a=Ia-xEzejAAAA:8 a=P4br88zyc6e5G4ArEiEA:9 a=lxShnrcy0RaHRf8CycAA:7 a=AkKEwZ524pT89GKyUIfmg3taPT4A:4 a=LKrNbxkub7wA:10 a=MSl-tDqOz04A:10 a=EzXvWhQp4_cA:10 a=rPkcCx1H5rrOSfN0dPC7kw==:117 X-Cloudmark-Score: 0 X-Originating-IP: 174.110.167.5 Received: from [174.110.167.5] ([174.110.167.5:62863] helo=EdPC) by cdptpa-oedge03.mail.rr.com (envelope-from ) (ecelerity 2.2.2.39 r()) with ESMTP id AB/6F-08566-8DA90BC4; Sat, 09 Oct 2010 16:39:52 +0000 Message-ID: <7CDF9B6B5E2A415DA13FD7C796EAA371@EdPC> From: "Ed Anderson" To: "Rotary motors in aircraft" , Subject: Fw: [FlyRotary] Re: Propeller design. Date: Sat, 9 Oct 2010 12:39:38 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_001A_01CB67AF.092C7F80" 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_001A_01CB67AF.092C7F80 Content-Type: text/plain; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable Pat, asked to post this to the list - another Lipps article in CONTACT! I'm going there to read it now Ed From: Pat Panzera=20 Sent: Saturday, October 09, 2010 12:19 PM To: eanderson@carolina.rr.com=20 Subject: Re: [FlyRotary] Re: Propeller design. Ed,=20 I can't post to the group so could you please let everyone know that the = current issue of CONTACT! Magazine has another Lipps article in it and = the entire issue can be downloaded for free off the website. = www.ContactMagazine,com Thanks! Pat On Sat, Oct 9, 2010 at 7:23 AM, Ed Anderson = wrote: Yes, a radially different concept for Prop design. I remember when = the bi-plane picked up something like a 20 MPH increase in speed with = Lipps prop - it had us all drooling to think that perhaps we could gain = a 10 MPH increase with our RV aircraft. Unfortunately, in the one = example I am somewhat familiar with when put on an Rv-6 the outcome was = somewhat disappointing - I think it was a gain of only about 1-2 MPH. Now in all fairness, Paul's admits his design approach is dependent on = somewhat untradiational accuracy in engine HP and drag of the platform = information - which may have been lacking in this first attempt. = However, since there has not been a flood of aircraft with the Lipps = prop, I'm inclined to believe that it has not yet reach the promise that = first seemed likely. While folks can point to the 20 mph increase in the bi plane's = performance, I can't help but wonder if perhaps the original prop on the = bi plane may have been a poor choice whereupon replacing it with the = Lipps (better matched) make the performance gain seem all related to the = Lipps prop rather than replacing what may have been a poor original = choice - but, just spectulation on my part. I really wanted to see the Lipps prop deliver all it initially seemed = to promise, but I can't find any data yet to support its initial promise = - at least on the type platforms and speeds we normally fly. It=92s the = first really different approach to prop design I've seen since - well, = since the Wright brothers {:>) If anybody has a source for information that indicates my impression = is incorrect regarding its performance on Rv type aircraft (or similar), = I would like to receive it. Thanks Ed From: Lehanover@aol.com=20 Sent: Saturday, October 09, 2010 9:53 AM To: Rotary motors in aircraft=20 Subject: [FlyRotary] Propeller design. http://www.eaa.org/experimenter/articles/2009-02_elippse.asp I sat through a talk by Paul Lipps at Gene Nevada at the alternative = engine seminar put on by Contact Magazine several years ago. He flew in his home built, with his propeller. Its outer blades were = the size of a 12" ruler. Imagine model sail plane wings, or bread knife = blades. He placed split tennis balls on the tips so guests did not stab = themselves on the blades. Later, he helped a guy design new wings for a biplane racer, and those = wings looked just like his propeller=20 blades. It had a 4 bladed Lipps propeller as well.=20 Not mentioned was the low wetted area of the blades would allow = greater span with less drag. The high angle of attack at the root = allowed playing card sized cooling inlets.=20 In the event of failed engine his prop has less than a 3rd of the = frontal area of a conventional prop. Not exactly full feathering, but better than anything else. So, if the blade has less drag for each unit of lift, then you could = add span until you get close to the ground, and then add blade count = until you have accounted for all of the available HP. Then you port the = rotary to get more HP. Warning, looking at a Lipps propeller blade may hurt your = mind...................... http://www.eaa.org/experimenter/articles/2009-02_elippse.asp Lynn E. Hanover ------=_NextPart_000_001A_01CB67AF.092C7F80 Content-Type: text/html; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable
Pat, asked to post this to the list - another = Lipps=20 article in CONTACT!
 
I'm going there to read it now
 
Ed

From: Pat Panzera
Sent: Saturday, October 09, 2010 12:19 PM
Subject: Re: [FlyRotary] Re: Propeller = design.

Ed,=20

I can't post to the group so could you please let everyone know = that the=20 current issue of CONTACT! Magazine has another Lipps article in it and = the=20 entire issue can be downloaded for free off the website. www.ContactMagazine,com
=

Thanks!

Pat

On Sat, Oct 9, 2010 at 7:23 AM, Ed Anderson = <eanderson@carolina.rr.com&g= t;=20 wrote:
Yes, a radially different concept for Prop = design.  I=20 remember when the bi-plane picked up something like a 20 MPH increase = in speed=20 with Lipps prop - it had us all drooling to think that perhaps we = could gain a=20 10 MPH increase with our RV aircraft.  Unfortunately, in the one = example=20 I am somewhat familiar with when put on an Rv-6 the outcome was = somewhat=20 disappointing - I think it was a gain of only about 1-2 = MPH.
 
Now in all fairness, Paul's admits his design = approach=20 is dependent on somewhat untradiational accuracy in engine HP and drag = of the=20 platform information - which may have been lacking in this first=20 attempt.  However, since there has not been a flood of aircraft = with the=20 Lipps prop, I'm inclined to believe that it has not yet reach the = promise that=20 first seemed likely.
 
While folks can point to the 20 mph increase in = the bi=20 plane's performance, I can't help but wonder if perhaps the original = prop on=20 the bi plane may have been a poor choice whereupon replacing it with = the Lipps=20 (better matched) make the performance gain seem all related to the = Lipps prop=20 rather than replacing what may have been a poor original choice - but, = just=20 spectulation on my part.
 
I really wanted to see the Lipps prop deliver all = it=20 initially seemed to promise, but I can't find any data yet to support = its=20 initial promise - at least on the type platforms and speeds we = normally=20 fly.  It=92s the first really different approach to prop design = I've seen=20 since - well, since the Wright brothers {:>)
 
If anybody has a source for information that = indicates my=20 impression is incorrect regarding its performance on Rv type aircraft = (or=20 similar), I would like to receive it.
 
Thanks
 
Ed

From: Lehanover@aol.com
Sent: Saturday, October 09, 2010 9:53 AM
To: Rotary = motors in=20 aircraft
Subject: [FlyRotary] Propeller design.

http://www.eaa.org/experimenter/articles/2009-02_elippse.= asp
 
I sat through a talk by Paul Lipps at Gene Nevada at the = alternative=20 engine seminar put on by Contact Magazine several years ago.
 
He flew in his home built, with his propeller. Its outer = blades were=20 the size of a 12" ruler. Imagine model sail plane wings, or bread = knife=20 blades. He placed split tennis balls on the tips so guests did not = stab=20 themselves on the blades.
 
Later, he helped a guy design new wings for a biplane racer, and = those=20 wings looked just like his propeller
blades. It had a 4 bladed Lipps propeller as well.
 
Not mentioned was the low wetted area of the blades would allow = greater=20 span with less drag. The high angle of attack at the root allowed = playing card=20 sized cooling inlets.
 
In the event of failed engine his prop has less than a 3rd of the = frontal=20 area of a conventional prop.
Not exactly full feathering, but better than anything else.
 
So, if the blade has less drag for each unit of lift, then you = could add=20 span until you get close to the ground, and then add blade count until = you=20 have accounted for all of the available HP. Then you port the rotary = to get=20 more HP.
 
Warning, looking at a Lipps propeller blade may hurt your=20 mind......................
 
 
Lynn E. Hanover
 
=
 

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