Gas Gun Design Tool - Revision history

GalFisk: /* Common problems for first time users */

2010-06-18T12:30:35Z

Common problems for first time users

← Older revision		Revision as of 07:30, 18 June 2010
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	Read, and follow, the [http://thehalls-in-bfe.com/GGDT/installation.html installation instructions] for GGDT before installing.		Read, and follow, the [http://thehalls-in-bfe.com/GGDT/installation.html installation instructions] for GGDT before installing.

	In the "Resevoir Data" section (parameters describing the pressure chamber) the default value for "Inner Diam" is 1.95 inch. This value is for a coaxial design where the barrels is within the chamber. For other designs, for example ball valves or ~~diaphram values~~, this value should be set to zero.		In the "Resevoir Data" section (parameters describing the pressure chamber) the default value for "Inner Diam" is 1.95 inch. This value is for a coaxial design where the barrels is within the chamber. For other designs, for example ball valves or diaphragm valves, this value should be set to zero.

	==Suitable parameters for various valves==		==Suitable parameters for various valves==

Ragnarok: /* Suitable parameters for various valves */

2008-10-04T02:53:40Z

Suitable parameters for various valves

← Older revision		Revision as of 21:53, 3 October 2008
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	C<sub>v</sub> = K * D<sup>2</sup>		C<sub>v</sub> = K * D<sup>2</sup>

	Where:		Where D is the seat diameter in centimetres, and K is

	~~K is:~~
	= 1 for a sprinkler or ball valve		= 1 for a sprinkler or ball valve
	= 2 for a piston of QEV		= 2 for a piston of QEV
	= 3 for a burst disc.		= 3 for a burst disc.
	~~D is the seat diameter in centimetres.~~

	This formula is not 100% accurate, but it's easy to use, remember, and reasonably accurate.		This formula is not 100% accurate, but it's easy to use, remember, and reasonably accurate.

Jimmy101: Added Ragnarok's Cv equation. Added Common question from first time users

2008-02-04T16:51:22Z

Added Ragnarok's Cv equation. Added Common question from first time users

← Older revision		Revision as of 11:51, 4 February 2008
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	Hall Consulting's '''Gas Gun Design Tool''' is a simulation program to aid the design of [[pneumatic cannon]]s. It is available [http://www.thehalls-in-bfe.com/GGDT here].		Hall Consulting's '''Gas Gun Design Tool''' is a simulation program to aid the design of [[pneumatic cannon]]s. It is available [http://www.thehalls-in-bfe.com/GGDT here].

			==Common problems for first time users==
			Read, and follow, the [http://thehalls-in-bfe.com/GGDT/installation.html installation instructions] for GGDT before installing.

			In the "Resevoir Data" section (parameters describing the pressure chamber) the default value for "Inner Diam" is 1.95 inch. This value is for a coaxial design where the barrels is within the chamber. For other designs, for example ball valves or diaphram values, this value should be set to zero.

			==Suitable parameters for various valves==
			''(This section needs a lot more info)''

			A rough rule of thumb for calculating the Flow Coefficient (C<sub>v</sub>) for various valve types;

			C<sub>v</sub> = K * D<sup>2</sup>

			Where:

			K is:
			= 1 for a sprinkler or ball valve
			= 2 for a piston of QEV
			= 3 for a burst disc.
			D is the seat diameter in centimetres.

			This formula is not 100% accurate, but it's easy to use, remember, and reasonably accurate.
			Using this formula we get a C<sub>v</sub> of 3.4 for a 1/2" [[QEV]].

	==Physics model==		==Physics model==

Benstern: spelling

2007-06-03T05:36:41Z

spelling

← Older revision		Revision as of 00:36, 3 June 2007
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	# Valve configuration and opening times. In fact, GGDT models five different types of valve: chamber sealing pilot (see [[piston valve]]s), barrel sealing pilot (ie, barrel sealing [[diaphragm valve]]s and [[piston valve]]s, [[burst disk]], [[hammer valve]], and "generic." Each of these valves have different behaviors and GGDT accounts for these behaviors (more on that below).		# Valve configuration and opening times. In fact, GGDT models five different types of valve: chamber sealing pilot (see [[piston valve]]s), barrel sealing pilot (ie, barrel sealing [[diaphragm valve]]s and [[piston valve]]s, [[burst disk]], [[hammer valve]], and "generic." Each of these valves have different behaviors and GGDT accounts for these behaviors (more on that below).
	# Pressure drop across the valve ~~oriface~~.		# Pressure drop across the valve orifice.
	# Temperature (and thus pressure) increase in the valve pilot due to work performed by gun gases on the valve piston/diaphragm.		# Temperature (and thus pressure) increase in the valve pilot due to work performed by gun gases on the valve piston/diaphragm.
	# Gas leakage from the main valve body into the upper valve chamber ([[pilot]]).		# Gas leakage from the main valve body into the upper valve chamber ([[pilot]]).
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	# Temperature effects on gas properties (and thus, performance).		# Temperature effects on gas properties (and thus, performance).
	# Performance limitations due to flow choking in the valve or the barrel.		# Performance limitations due to flow choking in the valve or the barrel.
	# Valve effective ~~oriface~~ increases due to lowered valve throat Mach number.		# Valve effective orifice increases due to lowered valve throat Mach number.
	# Temperature (and thus pressure) drop in the barrel due to work performed by the gas accelerating the projectile.		# Temperature (and thus pressure) drop in the barrel due to work performed by the gas accelerating the projectile.
	# Gas leakage around the projectile in the barrel.		# Gas leakage around the projectile in the barrel.

Boilingleadbath: categorized

2007-04-15T12:51:49Z

categorized

← Older revision		Revision as of 07:51, 15 April 2007
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	==Use==		==Use==
	See Hall's [http://www.thehalls-in-bfe.com/GGDT page] on use		See Hall's [http://www.thehalls-in-bfe.com/GGDT page] on use

	{{stub}}		{{stub}}
			[[category:Concepts]]

GalFisk: /* Physics model */ typo

2006-04-24T11:31:35Z

Physics model: typo

← Older revision		Revision as of 06:31, 24 April 2006
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	==Physics model==		==Physics model==
	As of version 4.2, in modeled the ~~fol owing~~ features:		As of version 4.2, in modeled the following features:

	# Valve configuration and opening times. In fact, GGDT models five different types of valve: chamber sealing pilot (see [[piston valve]]s), barrel sealing pilot (ie, barrel sealing [[diaphragm valve]]s and [[piston valve]]s, [[burst disk]], [[hammer valve]], and "generic." Each of these valves have different behaviors and GGDT accounts for these behaviors (more on that below).		# Valve configuration and opening times. In fact, GGDT models five different types of valve: chamber sealing pilot (see [[piston valve]]s), barrel sealing pilot (ie, barrel sealing [[diaphragm valve]]s and [[piston valve]]s, [[burst disk]], [[hammer valve]], and "generic." Each of these valves have different behaviors and GGDT accounts for these behaviors (more on that below).

GalFisk: updated URL

2006-04-24T11:31:20Z

updated URL

← Older revision		Revision as of 06:31, 24 April 2006
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	Hall Consulting's '''Gas Gun Design Tool''' is a simulation program to aid the design of [[pneumatic cannon]]s. It is available [http://~~www1~~.~~iwvisp~~.com~~/thehalls~~/GGDT~~/index.html~~ here].		Hall Consulting's '''Gas Gun Design Tool''' is a simulation program to aid the design of [[pneumatic cannon]]s. It is available [http://www.thehalls-in-bfe.com/GGDT here].

	==Physics model==		==Physics model==

GalFisk: /* Use */

2006-04-24T11:30:48Z

Use

← Older revision		Revision as of 06:30, 24 April 2006
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	==Use==		==Use==
	See Hall's [http://~~www1~~.~~iwvisp~~.com/~~thehalls/ggdt/index.html~~ page] on use		See Hall's [http://www.thehalls-in-bfe.com/GGDT page] on use
	{{stub}}		{{stub}}

70.31.208.207: spelling

2006-03-04T22:34:39Z

spelling

← Older revision		Revision as of 17:34, 4 March 2006
Line 2:		Line 2:

	==Physics model==		==Physics model==
	As of version 4.2, in ~~modled~~ the ~~folowing~~ features:		As of version 4.2, in modeled the fol owing features:

	# Valve configuration and opening times. In fact, GGDT models five different types of valve: chamber sealing pilot (see [[piston valve]]s), barrel sealing pilot (ie, barrel sealing [[diaphragm valve]]s and [[piston valve]]s, [[burst disk]], [[hammer valve]], and "generic." Each of these valves have different behaviors and GGDT accounts for these behaviors (more on that below).		# Valve configuration and opening times. In fact, GGDT models five different types of valve: chamber sealing pilot (see [[piston valve]]s), barrel sealing pilot (ie, barrel sealing [[diaphragm valve]]s and [[piston valve]]s, [[burst disk]], [[hammer valve]], and "generic." Each of these valves have different behaviors and GGDT accounts for these behaviors (more on that below).
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	However, these are not a major concern in most launchers, as they require very long barrels or very high pressures to notice.		However, these are not a major concern in most launchers, as they require very long barrels or very high pressures to notice.
	~~Typicaly~~, the GGDT outputs numbers within 5-10% of the measured value, although this is somewhat clouded by not knowing the proper input numbers.		Typically, the GGDT outputs numbers within 5-10% of the measured value, although this is somewhat clouded by not knowing the proper input numbers.

	==Use==		==Use==
	See Hall's [http://www1.iwvisp.com/thehalls/ggdt/index.html page] on use		See Hall's [http://www1.iwvisp.com/thehalls/ggdt/index.html page] on use
	{{stub}}		{{stub}}

Boilingleadbath: -link mistake

2005-12-17T21:55:19Z

-link mistake

← Older revision		Revision as of 16:55, 17 December 2005
Line 4:		Line 4:
	As of version 4.2, in modled the folowing features:		As of version 4.2, in modled the folowing features:

	# Valve configuration and opening times. In fact, GGDT models five different types of valve: chamber sealing pilot (see [[piston valve]]s), barrel sealing pilot (ie, barrel sealing [[~~diaphram~~ valve]]s and [[piston ~~valves~~]], [[burst ~~disc~~]], [[hammer valve]], and "generic." Each of these valves have different behaviors and GGDT accounts for these behaviors (more on that below).		# Valve configuration and opening times. In fact, GGDT models five different types of valve: chamber sealing pilot (see [[piston valve]]s), barrel sealing pilot (ie, barrel sealing [[diaphragm valve]]s and [[piston valve]]s, [[burst disk]], [[hammer valve]], and "generic." Each of these valves have different behaviors and GGDT accounts for these behaviors (more on that below).
	# Pressure drop across the valve oriface.		# Pressure drop across the valve oriface.
	# Temperature (and thus pressure) increase in the valve pilot due to work performed by gun gases on the valve piston/diaphragm.		# Temperature (and thus pressure) increase in the valve pilot due to work performed by gun gases on the valve piston/diaphragm.