X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mail10.syd.optusnet.com.au ([211.29.132.191] verified) by logan.com (CommuniGate Pro SMTP 5.1.12) with ESMTPS id 2349650 for flyrotary@lancaironline.net; Mon, 24 Sep 2007 18:49:26 -0400 Received-SPF: none receiver=logan.com; client-ip=211.29.132.191; envelope-from=lendich@optusnet.com.au Received: from george (d211-31-87-129.dsl.nsw.optusnet.com.au [211.31.87.129]) by mail10.syd.optusnet.com.au (8.13.1/8.13.1) with SMTP id l8OMmULt016948 for ; Tue, 25 Sep 2007 08:48:31 +1000 Message-ID: <007101c7fefd$0e40b090$81571fd3@george> From: "George Lendich" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Area of a circle Date: Tue, 25 Sep 2007 08:48:40 +1000 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_006E_01C7FF50.DEDCFE40" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.2180 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2180 X-Antivirus: avast! (VPS 0657-0, 12/12/2006), Outbound message X-Antivirus-Status: Clean This is a multi-part message in MIME format. ------=_NextPart_000_006E_01C7FF50.DEDCFE40 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Thanks Bill, I will look at that as well! Is that 4H squared or 4x ( h squared) George (down under) George, You need to solve for the area of the circular segment opened by the = slide throttle. The formula is A=3D1/2[rl-c(r-h)]=20 A=3Darea, r-radius, l=3Dlenght on the perimeter, c=3Dchord, h=3Dchord = height Since lenght on the perimeter can be tough to determine, there is an = alternate formula. There is a slight error (less than .1%)=20 A=3D4h^2/3 times sq root of c^2/4h^2+0.392 area equals four times h squared divided by three times the square = root of c squared divided by 4 times h squared plus 0.392 (pg 75 mahninery's handbook 21st ed.) That will give you the cordal area of 1/2 of the opening obviously. = You can figure the cross-sectional area of the needle to remove. You can = do openings at various throttle openings and then graph of extrapolate = the points between. Good luck! Bill Jepson -----Original Message----- From: George Lendich To: Rotary motors in aircraft Sent: Sat, 22 Sep 2007 4:55 pm Subject: [FlyRotary] Re: Area of a circle Al, I am using a slide throttle and initially thought I would just do = trial and error, but figured if I could just get a handle on variables = it would help with the initial taper grind on the needle. I guess I = could just go linier and see how that goes. I could use an O2 sensor to = check fuel/air ratio, then regrind a new needle. George (down under) -------------------------------------------------------------------------= ----- Email and AIM finally together. You've gotta check out free AOL Mail! -------------------------------------------------------------------------= ----- No virus found in this incoming message. Checked by AVG Free Edition.=20 Version: 7.5.488 / Virus Database: 269.13.30/1025 - Release Date: = 23/09/2007 1:53 PM ------=_NextPart_000_006E_01C7FF50.DEDCFE40 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

Thanks Bill,

I will look at that as = well!

Is that 4H squared or 4x ( h = squared)

George (down under)

George,
You=20 need to solve for the area of the circular segment opened by the slide = throttle. The formula = is =20 A=3D1/2[rl-c(r-h)]
A=3Darea, r-radius, l=3Dlenght on the = perimeter, c=3Dchord,=20 h=3Dchord height
Since lenght on the perimeter can be tough to = determine,=20 there is an alternate formula. There is a slight error (less than .1%) =

A=3D4h^2/3 times sq root of c^2/4h^2+0.392
area equals four = times h=20 squared divided by three times the square root of c squared divided by = 4 times=20 h squared plus 0.392
(pg 75 mahninery's handbook 21st = ed.)

That will=20 give you the cordal area of 1/2 of the opening obviously. You can = figure the=20 cross-sectional area of the needle to remove. You can do openings at = various=20 throttle openings and then graph of extrapolate the points between. = Good=20 luck!
Bill Jepson

-----Original Message-----
From: = George=20 Lendich <lendich@optusnet.com.au>
To: Rotary motors in = aircraft=20 <flyrotary@lancaironline.net>
Sent: Sat, 22 Sep 2007 4:55=20 pm
Subject: [FlyRotary] Re: Area of a circle

Al,

I am using a slide throttle and = initially thought=20 I would just do trial and error, but figured if I could just get a = handle on=20 variables it would help with the initial taper grind on the needle. I = guess I=20 could just go linier and see how that goes. I could use an O2 sensor = to check=20 fuel/air ratio, then regrind a new needle.

George (down = under)

Email and AIM finally together. You've gotta check out free AOL Mail!

No virus found in this incoming message.
Checked by AVG Free = Edition.
Version: 7.5.488 / Virus Database: 269.13.30/1025 - = Release Date:=20 23/09/2007 1:53 PM
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