Return-Path: Received: from fed1mtao03.cox.net ([68.6.19.242] verified) by logan.com (CommuniGate Pro SMTP 4.1.8) with ESMTP id 2959686 for flyrotary@lancaironline.net; Sat, 31 Jan 2004 11:50:28 -0500 Received: from BigAl ([68.107.116.221]) by fed1mtao03.cox.net (InterMail vM.5.01.06.05 201-253-122-130-105-20030824) with ESMTP id <20040131165028.VRVW3721.fed1mtao03.cox.net@BigAl> for ; Sat, 31 Jan 2004 11:50:28 -0500 From: "Al Gietzen" To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Re: air flow Date: Sat, 31 Jan 2004 08:50:31 -0800 Message-ID: <001d01c3e81a$56ad5660$6400a8c0@BigAl> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_001E_01C3E7D7.488A1660" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.4024 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_001E_01C3E7D7.488A1660 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Here is a formula 80 CID * RPM/1728. Example for 6000 rpm, 80*6000 rpm/1728 = 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 = 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 ------=_NextPart_000_001E_01C3E7D7.488A1660 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

 

 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.

 <= /font>

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

 <= /font>

Thanks.=

 <= /font>

Al

------=_NextPart_000_001E_01C3E7D7.488A1660--