Return-Path: <13brv3@bellsouth.net> Received: from imf18aec.mail.bellsouth.net ([205.152.59.66] verified) by logan.com (CommuniGate Pro SMTP 4.2b1) with ESMTP id 3151787 for flyrotary@lancaironline.net; Wed, 07 Apr 2004 21:52:28 -0400 Received: from rad ([68.221.181.100]) by imf18aec.mail.bellsouth.net (InterMail vM.5.01.06.08 201-253-122-130-108-20031117) with ESMTP id <20040408015228.FXIS1781.imf18aec.mail.bellsouth.net@rad> for ; Wed, 7 Apr 2004 21:52:28 -0400 From: "Russell Duffy" <13brv3@bellsouth.net> To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Help Rusty pick a prop Date: Wed, 7 Apr 2004 20:52:33 -0500 Message-ID: <038b01c41d0c$28ceefc0$6001a8c0@rad> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_038C_01C41CE2.3FF8E7C0" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.4510 X-MIMEOLE: Produced By Microsoft MimeOLE V6.00.2800.1165 In-Reply-To: Importance: Normal This is a multi-part message in MIME format. ------=_NextPart_000_038C_01C41CE2.3FF8E7C0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Just a thought, and without running the numbers can't be sure. Maybe someone will run the numbers with the Roncz program and post the results (and take the guesswork out of the equation). Ken Powell =20 Hi Ken, =20 I've run a number of prop programs, and just ran the one you sent. Unfortunately, the optimum tip speed range seems to be in question. = Some programs say 850 fps, some say 900 fps, and more say .88-.92 Mach. = Marko has a nice program, that I've been playing with also. Bottom line is = that I think a 68" prop can easily run a max of 3200 rpm, and perhaps as high = as 3400 without getting too far from the optimized range. I've got nothing = to lose by trying it, as I'm sure it won't hurt the engine. =20 =20 Cheers, Rusty =20 =20 ------=_NextPart_000_038C_01C41CE2.3FF8E7C0 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Message

Just a thought, and without running the numbers can't = be=20 sure.  Maybe someone will run the numbers with the Roncz program = and post=20 the results (and take the guesswork out of the equation).

Ken=20 Powell

 
Hi=20 Ken,
 
I've run = a number of=20 prop programs, and just ran the one you sent.  Unfortunately, the = optimum=20 tip speed range seems to be in question.  Some programs say 850 = fps, some=20 say 900 fps, and more say .88-.92 Mach.  Marko has a nice program, = that=20 I've been playing with also.  Bottom line is that I think a 68" = prop can=20 easily run a max of 3200 rpm, and perhaps as high as 3400 without = getting too=20 far from the optimized range.  I've got nothing to lose by trying = it, as=20 I'm sure it won't hurt the engine. 
 
Cheers,
Rusty
 
 


 ------=_NextPart_000_038C_01C41CE2.3FF8E7C0--