Mailing List flyrotary@lancaironline.net Message #37558
From: Bob White <rlwhite@comcast.net>
Subject: Re: [FlyRotary] Re: PP Ve??? was Re: Intake CFM air flow
Date: Fri, 1 Jun 2007 15:02:19 -0600
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
HI Blake,

Ah! It's even higher.  I should have looked more closely at the
formulae.  I saw you were dividing 1300 by something then didn't notice
the result was used in the denominator of the next formula.  Sorry
about that. :)

Bob W.

On Fri, 1 Jun 2007 15:53:55 -0500
"Blake Lewis" <blake.lewis@gmail.com> wrote:

Bob,
You corrected the wrong way. And I had 10000 instead of 10700 rpm.

12A  Pports can do 310 HP at 10,700 RPM at .667

If the .667 is BSFC then start with that

Density of air at sea level 15C = .0765 lbs/cf air/fuel = 12

.667 bsfc x 310hp is 206.77 lbs/hr fuel

206.77lbs x 12 = 2481.24 lbs/hr air

2481.24 lbs/hr  /  60min/hr = 41.354 lbs/min

(41.354 lbs/min)  / (.0765 lbs/cf) * (1728 ci/cf) = 93411 ci /min

(934113ci/min) / (10700 rev/min) = 87.30 ci/rev

1200cc / (2.54cm * 2.54cm * 2.54cm)/ci = 73.22 ci volume

87.30 ci/rev / 73.22 ci/rev = 1.192 =119% VE

Blake

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