X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from poplet4.per.eftel.com ([203.24.100.41] verified) by logan.com (CommuniGate Pro SMTP 5.3.9) with ESMTP id 4481066 for flyrotary@lancaironline.net; Sat, 25 Sep 2010 17:44:57 -0400 Received-SPF: none receiver=logan.com; client-ip=203.24.100.41; envelope-from=lendich@aanet.com.au Received: from sv1-1.aanet.com.au (mail.aanet.com.au [203.24.100.34]) by poplet4.per.eftel.com (Postfix) with ESMTP id CD7373BEA7 for ; Sun, 26 Sep 2010 05:44:20 +0800 (WST) Received: from ownerf1fc517b8 (203.171.92.134.static.rev.aanet.com.au [203.171.92.134]) by sv1-1.aanet.com.au (Postfix) with SMTP id 1EDCFC5CDD for ; Sun, 26 Sep 2010 05:44:19 +0800 (WST) Message-ID: <680CA2C8A4594AEEA630146AACA45BEB@ownerf1fc517b8> From: "George Lendich" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] simple dyno Date: Sun, 26 Sep 2010 07:44:22 +1000 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_001D_01CB5D4E.A27B1A40" 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 X-Antivirus: avast! (VPS 100925-0, 09/25/2010), Outbound message X-Antivirus-Status: Clean This is a multi-part message in MIME format. ------=_NextPart_000_001D_01CB5D4E.A27B1A40 Content-Type: text/plain; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable Andrew, I'm a bit confused with what you have provided, so just to clarify I = will ask if this is what your saying in regard to the calculation:- Power in HP =3D 0.0532 times ( diameter of prop divided by 450) by 5 = times ( rpm divided by 1,000) multiplied by 3 OR is the 5 and 3 ( to the power of). Secondly, the 'square cross section' statement - for the balanced bar, I = assume you mean thickness, which would then mean for a 6' ( 72") bar it = would be 4.8" thick - is that correct? George ( down under) Brisbane. Whilst researching propellers, I came across this gem of info from = www.jcpropellerdesign.com Gustave Eiffel (1832-1923) came up with a simple solution for = measuring HP without complex apparatus, By using a balanced wood bar = instead of a propeller with a square cross section of 1/15th of the = length of the bar, you can measure the rpm and calculate the HP = available. Power in HP =3D 0.0532 (diameter/450)5 (RPM/1000)3 As I need a load on the engine when I run it I=92m going to give this = a go, 1350 x 90mm at 7000 rpm will give me 191hp, that=92ll do if I can = get it. --=20 Regards Andrew Martin Renesis RD1c=20 West Australia ------=_NextPart_000_001D_01CB5D4E.A27B1A40 Content-Type: text/html; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable
Andrew,
I'm a bit confused with what you have = provided, so=20 just to clarify I will ask if this is what your saying in regard to the=20 calculation:-
 
Power in HP =3D 0.0532 times ( diameter = of prop=20 divided by 450) by 5 times ( rpm divided by 1,000) multiplied by = 3
OR is the 5 and 3 ( to the power = of).
 
Secondly, the 'square cross section' = statement -=20 for the balanced bar, I assume you mean thickness, which would then mean = for a=20 6' ( 72") bar it would be 4.8" thick - is that correct?
 
George ( down under) = Brisbane.
Whilst=20 researching propellers, I came across this gem of info from www.jcpropellerdesign.com

Gustave Eiffel (1832-1923) came up with a simple = solution=20 for measuring HP without complex apparatus, By using a balanced = wood=20 bar instead of a propeller with a square cross section of = 1/15th of the=20 length of the bar, you can measure the rpm and calculate the HP=20 available.
Power in HP =3D 0.0532 (diameter/450)5 (RPM/1000)3

As I need a load = on the engine=20 when I run it I=92m going to give this a go, 1350 x 90mm at 7000 rpm = will give=20 me 191hp, that=92ll do if I can get it.
--=20
Regards

Andrew Martin
Renesis RD1c
West Australia
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