Return-Path: Received: from [24.25.9.102] (HELO ms-smtp-03-eri0.southeast.rr.com) by logan.com (CommuniGate Pro SMTP 4.1.8) with ESMTP id 2959926 for flyrotary@lancaironline.net; Sat, 31 Jan 2004 13:54:13 -0500 Received: from edward (clt78-020.carolina.rr.com [24.93.78.20]) by ms-smtp-03-eri0.southeast.rr.com (8.12.10/8.12.7) with SMTP id i0VIsA5X003743 for ; Sat, 31 Jan 2004 13:54:11 -0500 (EST) Message-ID: <002c01c3e82b$9c099fa0$2402a8c0@edward> From: "Ed Anderson" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: air flow Date: Sat, 31 Jan 2004 13:54:09 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0029_01C3E801.B2E29170" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2800.1158 X-MIMEOLE: Produced By Microsoft MimeOLE V6.00.2800.1165 X-Virus-Scanned: Symantec AntiVirus Scan Engine This is a multi-part message in MIME format. ------=_NextPart_000_0029_01C3E801.B2E29170 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable =20 -----=20 From: Al Gietzen=20 To: Rotary motors in aircraft=20 Sent: Saturday, January 31, 2004 11:50 AM Subject: [FlyRotary] Re: air flow Here is a formula 80 CID * RPM/1728. Example for 6000 rpm, = 80*6000 rpm/1728 =3D 277.77 Cubic Feet of air per minute. A cubic foot of air = (at sea level standard day) is approx 0.076 lbm/cubic foot so 277.77*0.076 = =3D 21.11 lbm/min air mass at 6000 rpm . Just change the rpm to what ever value = you want. Also note the weight of air of course decreases with altitude = so 277.77 CFM provides 21.11 lbm/minute at sea level but less at = altitude. Note this assumes 100 % Volumetric efficiency. Ed Anderson Oh; boy, now you've done it. My beautiful intake scoop is already = installed, and I apparently designed it based on the wrong number. You're numbers look right to me. I'll have see if I can figure out = what I did. Thanks. Al Your Welcome, Al Perhaps you used the correct number for the design and just had a = brain fade when you quoted the number for CFM - Hopefully? Ed Anderson ------=_NextPart_000_0029_01C3E801.B2E29170 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
 
 
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From:=20 Al = Gietzen=20
Sent: Saturday, January 31, = 2004 11:50=20 AM
Subject: [FlyRotary] Re: air = flow

 

 Here is a formula   80 CID * = RPM/1728.  Example for 6000 rpm,  80*6000

rpm/1728 =3D 277.77 Cubic Feet of air per = minute. =20 A cubic foot of air (at sea

level standard day) is approx 0.076 = lbm/cubic=20 foot   so 277.77*0.076 =3D 21.11

lbm/min air mass at 6000 rpm .  Just = change the=20 rpm to what ever value you

want.  Also note the weight of air of = course=20 decreases with altitude so

277.77 CFM provides 21.11 lbm/minute at sea = level but=20 less at altitude.

 

Note this assumes 100 % Volumetric=20 efficiency.

 

Ed Anderson

 

Oh; boy, = now=20 you=92ve done it.  My beautiful intake scoop is already = installed, and I=20 apparently designed it based on the wrong number.

 

You=92re = numbers=20 look right to me.  I=92ll have see if I can figure out what I=20 did.

 

Thanks.

 

Al

 

Your = Welcome,=20 Al

 

   =20 Perhaps you used the correct number for the design and just had a = brain fade=20 when you quoted the number for CFM - Hopefully?

 

Ed=20 Anderson

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