Return-Path: Received: from cmailm4.svr.pol.co.uk ([195.92.193.211] verified) by logan.com (CommuniGate Pro SMTP 4.1.8) with ESMTP id 3114676 for flyrotary@lancaironline.net; Tue, 23 Mar 2004 03:13:28 -0500 Received: from modem-2792.chameleon.dialup.pol.co.uk ([217.134.90.232] helo=cliveclapham) by cmailm4.svr.pol.co.uk with smtp (Exim 4.14) id 1B5h2M-0004lh-PE for flyrotary@lancaironline.net; Tue, 23 Mar 2004 08:13:27 +0000 Message-ID: <003901c410ae$b351c150$e85a86d9@l29818.findquick.com> From: "clive CLAPHAM" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Data? Was : Renesis & RD-1C drive testing Date: Tue, 23 Mar 2004 08:13:18 -0000 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0036_01C410AE.B2AFDC00" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2720.3000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2727.1300 This is a multi-part message in MIME format. ------=_NextPart_000_0036_01C410AE.B2AFDC00 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Hi We found the same thing on Q2 vs Q235 the larger coarse prop had a lower = drag than the small fine pitch. The glide ratio with the Q235 is about = 13:1 compared to a brick. We have tried a constant speed on the Q2 and = I was amazed at how much drag you could get when set max fine pitch. P factor I suspect that the apparent surprise is to do with the reverse = rotation of you former set up cancelling out some of the P factor = (engine one way prop other way) so you mostly only have air flow related = P factor. Now you got engine+prop rotation+air flow to contend with. = All good fun! =20 Clive Clapham Progress on direct drive 13B painfully slow. ----- Original Message -----=20 From: Tracy Crook=20 To: Rotary motors in aircraft=20 Sent: Monday, March 22, 2004 4:25 AM Subject: [FlyRotary] Re: Data? Was : Renesis & RD-1C drive testing > =20 > Most unexpected finding so far is the radically improved glide at = idle=20 > setting. Have no clue why. Would have expected worse instead of = better. > =20 > Tracy Don't you have radically increased pitch in the prop? That will do = it. Charlie Yep, 88" pitch. Guess I figured even at that blade angle air flow = would be fully stalled past the prop and the disk area being larger = would cause more drag. I was obviously wrong. =20 Also noticed that having a direct MPG readout makes finding the most = efficient descent angle & throttle setting easy to find. It's a lot = different than on the other redrive/prop. Tracy ------=_NextPart_000_0036_01C410AE.B2AFDC00 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Hi
 
We found the same thing on Q2 vs Q235 the larger = coarse=20 prop had a lower drag than the small fine pitch.  The glide ratio = with the=20 Q235 is about 13:1 compared to a brick.  We have tried a = constant=20 speed on the Q2 and I was amazed at how much drag you could get when set = max=20 fine pitch.
 
P factor I suspect that the apparent = surprise is to=20 do with the reverse rotation of you former set up cancelling out some of = the P=20 factor (engine one way prop other way) so you mostly only have air flow = related=20 P factor.  Now you got engine+prop rotation+air flow to contend=20 with. All good fun! 
 
Clive Clapham
 
Progress on direct drive 13B painfully = slow.
----- Original Message -----
From:=20 Tracy = Crook
Sent: Monday, March 22, 2004 = 4:25=20 AM
Subject: [FlyRotary] Re: Data? = Was :=20 Renesis & RD-1C drive testing

 
 

> 
> Most unexpected finding so far is the = radically=20 improved glide at idle
> setting.  Have no clue = why.  Would=20 have expected worse instead of better.
> 
>=20 Tracy

Don't you have radically increased pitch in the prop? = That will=20 do it.

Charlie

Yep, 88" pitch.  Guess I figured even at that blade angle = air flow=20 would be fully stalled past the prop and the disk area being = larger=20 would cause more drag.  I was obviously wrong. 

Also noticed that having a direct MPG readout makes finding the = most=20 efficient descent angle & throttle setting easy to find.  = It's a=20 lot different than on the other redrive/prop.

Tracy

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