56 lines
1.9 KiB
Groff
56 lines
1.9 KiB
Groff
.\"
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.\" Copyright © 2009 Keith Packard <keithp@keithp.com>
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.\"
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.\" This program is free software; you can redistribute it and/or modify
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.\" it under the terms of the GNU General Public License as published by
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.\" the Free Software Foundation; either version 2 of the License, or
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.\" (at your option) any later version.
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.\"
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.\" This program is distributed in the hope that it will be useful, but
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.\" WITHOUT ANY WARRANTY; without even the implied warranty of
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.\" MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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.\" General Public License for more details.
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.\"
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.\" You should have received a copy of the GNU General Public License along
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.\" with this program; if not, write to the Free Software Foundation, Inc.,
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.\" 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
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.\"
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.\"
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.TH AO-EJECTION 1 "ao-ejection" ""
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.SH NAME
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ao-ejection \- Compute rocket ejection charges
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.SH SYNOPSIS
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.B "ao-ejection"
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\fIdiameter(mm)\fP
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\fIlength(mm)\fP
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\fIforce(N)\fP
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.SH DESCRIPTION
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.I ao-ejection
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computes the amount of black powder necessary to generate the desired
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force to separate sections of a rocket airframe. It assumes a
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cylindrical airspace covered by a circular cap. With that and the
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force to be exerted on the cap,
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.I ao-ejection
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can compute the necessary pressure rise within the chamber, the volume
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of gas necessary and finally the mass of BP to generate the gas.
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.SH EXAMPLE
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.nf
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$ ao-ejection 54 300 500
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Input parameters:
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Diameter: 54.0 (mm) 2.126 (in)
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Length: 300.0 (mm) 11.811 (in)
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Force: 500.0 (N) 112.404 (lb)
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Chamber values:
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Area: 2290 (mm²) 3.550 (in²)
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Volume: 687066 (mm³) 41.927 (in³)
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Pressure: 31.66 (lb/in²) 0.21832 (N/mm²)
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Results:
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FFFF powder: 0.685 (g)
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.fi
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.P
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This demonstrates that a 54mm airframe with a 300mm chamber
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requires .685g of FFFF BP to generate 112lb of force on the end of the
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chamber. This is usually sufficient to sever two 2x56 nylon screws.
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.SH AUTHOR
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Keith Packard
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