X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from smtp1.av-mx.com ([137.118.16.57] verified) by logan.com (CommuniGate Pro SMTP 5.3.9) with ESMTP id 4500309 for flyrotary@lancaironline.net; Sun, 10 Oct 2010 10:12:26 -0400 Received-SPF: pass receiver=logan.com; client-ip=137.118.16.57; envelope-from=res12@fairpoint.net Received: from main (unknown [209.105.170.97]) (Authenticated sender: res12@fairpoint.net) by smtp1.av-mx.com (Postfix) with ESMTP id 2E9C329158C for ; Sun, 10 Oct 2010 10:11:49 -0400 (EDT) Message-ID: <1DC59242621E4F84826EB74EE0CEB029@main> From: "Richard Sohn" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Propeller design. Date: Sun, 10 Oct 2010 09:12:02 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0009_01CB685B.33578F00" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.5931 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5994 This is a multi-part message in MIME format. ------=_NextPart_000_0009_01CB685B.33578F00 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Thanks George, Richard Sohn N2071U ----- Original Message -----=20 From: George Lendich=20 To: Rotary motors in aircraft=20 Sent: Saturday, October 09, 2010 11:44 PM Subject: [FlyRotary] Re: Propeller design. Richard, I emailed Paul Lipps some years back and he sent me similar photos, = to show he wasn't the first to understand the principle - it's basically = making the inner part of the prop do more of the work. After reading the = write-up I understand more of the reasons why. As Ed has mentioned it might be that the input might need to more = concise, than traditional props - interesting just the same. George (down under) =20 ----- Original Message -----=20 From: Lehanover@aol.com=20 To: Rotary motors in aircraft=20 Sent: Saturday, October 09, 2010 8:53 AM 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 Is this a time warp? I found this picture in Flieger Revue 09/2010. The picture was = taken sometime during 1926-27 flight testing.=20 Just look at the prop. Richard Sohn N2071U -------------------------------------------------------------------------= --- -- Homepage: http://www.flyrotary.com/ Archive and UnSub: = http://mail.lancaironline.net:81/lists/flyrotary/List.html ------=_NextPart_000_0009_01CB685B.33578F00 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Thanks George,
 
Richard Sohn
N2071U
----- Original Message -----
From:=20 George=20 Lendich
Sent: Saturday, October 09, = 2010 11:44=20 PM
Subject: [FlyRotary] Re: = Propeller=20 design.

 
 Richard,
 I emailed Paul Lipps some = years back and=20 he sent me similar photos, to show he wasn't the first to understand = the=20 principle - it's basically making the inner part of the prop do more = of the=20 work. After reading the write-up I understand more of the=20 reasons why.
As Ed has mentioned it might be that = the input=20 might need to more concise, than traditional props - interesting = just the=20 same.
George (down = under)  
 
----- Original Message ----- =
From:=20 Lehanover@aol.com
To: Rotary motors in = aircraft=20
Sent: Saturday, October 09, = 2010 8:53=20 AM
Subject: [FlyRotary] = Propeller=20 design.

htt= p://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=20 were the size of a 12" ruler. Imagine model sail plane wings, or = bread=20 knife blades. He placed split tennis balls on the tips so guests = did not=20 stab themselves on the blades.
 
Later, he helped a guy design new wings for a biplane racer, = and=20 those 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=20 greater span with less drag. The high angle of attack at the root = allowed=20 playing card sized cooling inlets.
 
In the event of failed engine his prop has less than a 3rd of = the=20 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=20 add span until you get close to the ground, and then add blade = count until=20 you have accounted for all of the available HP. Then you port the = rotary=20 to get more HP.
 
Warning, looking at a Lipps propeller blade may hurt your=20 mind......................
 
htt= p://www.eaa.org/experimenter/articles/2009-02_elippse.asp
 
Lynn E. Hanover
 
Is this a time warp?
 
I found this picture in Flieger Revue 09/2010. The picture = was taken=20 sometime during 1926-27 flight testing.
 
Just look at the prop.
 
Richard Sohn
N2071U
 
 
 
 

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