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Updated Submarine Scout:
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- Improved modelling for the automatic valves.
- Moved the air and gas system to a file of its own.
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@andgi
andgi committed Feb 21, 2011
1 parent de03d81 commit 0013ef4
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144 changes: 19 additions & 125 deletions Submarine_Scout.xml
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Submarine Scout airship flight model for JSBSim.
Copyright (C) 2007 - 2010 Anders Gidenstam (anders(at)gidenstam.org)
Copyright (C) 2007 - 2011 Anders Gidenstam (anders(at)gidenstam.org)
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
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<email>anders at gidenstam dot org</email>

<filecreationdate>2007-02-11</filecreationdate>
<version>$Id: Submarine_Scout.xml,v 1.54 2010-05-19 21:00:25 anders Exp $</version>
<version>$Id: Submarine_Scout.xml,v 1.55 2011-02-21 21:05:34 anders Exp $</version>

<license>
<licenseName>GPL</licenseName>
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<documentation>
According to [VentryKo:1982:AS] page 44 these ships normally carried
two 65lb bombs set as depth charges.

According to [Mowthrope:1998:Battlebags] the SSZ type could carry either
two 110lb or one 250lb bomb on each side of the car.

The inspiration for my bomb model appears to be a 110lb bomb
from a photo of the car of SSZ.27.
</documentation>
<pointmass name="Bomb1">
<weight unit="LBS"> 65.0 </weight>
<weight unit="LBS"> 110.0 </weight>
<location name="POINTMASS" unit="M">
<x> 17.00 </x>
<y> -0.57 </y>
<z> -7.35 </z>
</location>
</pointmass>
<pointmass name="Bomb2">
<weight unit="LBS"> 65.0 </weight>
<weight unit="LBS"> 110.0 </weight>
<location name="POINTMASS" unit="M">
<x> 17.00 </x>
<y> 0.57 </y>
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<documentation>
NOTE: The cell is placed based on the envelope centroid location
as computed by BRLCAD.
The automatic valves are implemented using a system.
</documentation>
<documentation>
Envelope and gas control for a S.S. b.E.2C according to [Whale:1919:BA]:
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- Nose stiffeners: 24
- 2 Ballonets
- capacity 6,375 feet^3 each
- automatic spring valves set to open at 25 - 28mm (of water I presume)
- automatic spring valves set to open at 25 - 28mm water.
- 2 gas valves one at the bottom and one at the top of the envelope
- Bottom valve automatically opens at 30 - 35mm pressure.
- Bottom valve automatically opens at 30 - 35mm water pressure.
- Top valve is manual only
</documentation>
<documentation>
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<x_radius unit="M"> 22.86 </x_radius>
<y_radius unit="M"> 4.55 </y_radius>
<z_radius unit="M"> 4.55 </z_radius>
<max_overpressure unit="PA"> 340.0 </max_overpressure>
<max_overpressure unit="PA"> 395.0 </max_overpressure>
<valve_coefficient unit="M4*SEC/KG"> 0.0075 </valve_coefficient>
<fullness>0.90</fullness>

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<x_radius unit="M"> 6.45 </x_radius>
<y_radius unit="M"> 3.00 </y_radius>
<z_radius unit="M"> 2.23 </z_radius>
<max_overpressure unit="PA"> 255.0 </max_overpressure>
<max_overpressure unit="PA"> 295.0 </max_overpressure>
<valve_coefficient unit="M4*SEC/KG"> 0.01 </valve_coefficient>
<fullness>0.15</fullness>
<heat>
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<x_radius unit="M"> 7.55 </x_radius>
<y_radius unit="M"> 2.85 </y_radius>
<z_radius unit="M"> 2.00 </z_radius>
<max_overpressure unit="PA"> 250.0 </max_overpressure>
<max_overpressure unit="PA"> 295.0 </max_overpressure>
<valve_coefficient unit="M4*SEC/KG"> 0.01 </valve_coefficient>
<fullness>0.15</fullness>
<heat>
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Pilot:
- watch
- air-speed indicator graduated in knots
- aneroid (pressure altimeter?) reading to 10,000 feet.
- aneroid (pressure altimeter) reading to 10,000 feet.
- Elliot revolution counter (tachometer?)
- Clift inclinometer reading up to 20 degrees depression or elevation.
- map case
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<value> 1.0 </value>
<quotient>
<property> instrumentation/gas-pressure-psf </property>
<value> 5.12 </value> <!-- about 25mm water. -->
<value> 3.50 </value> <!-- about 17mm water. -->
</quotient>
</min>
</max>
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</limitation>
</system>

<system name="Ballonet and gas control">
<system file="air-and-gas-control-jsbsim">

<documentation>
"Two ballonets are provided, one forward and one aft, the capacity
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relative wind into account.
</limitation>

<!-- Pilot inputs. -->
<property value="0.0">fcs/gas-valve-cmd-norm[0]</property>
<property value="0.0">fcs/ballonet-valve-cmd-norm[0]</property>
<property value="0.0">fcs/ballonet-valve-cmd-norm[1]</property>
<property value="0.0">fcs/ballonet-crabpot-valve-cmd-norm[0]</property>
<property value="0.0">fcs/ballonet-crabpot-valve-cmd-norm[1]</property>
<property value="0.0">fcs/rip-cord-cmd-norm</property>

<channel name="Gas valve">

<switch name="fcs/ripped-sample-hold">
<default value="fcs/rip-cord-cmd-norm"/>
<test logic="AND" value="fcs/ripped-sample-hold">
fcs/ripped-sample-hold GE 1.0
</test>
</switch>

<fcs_function name="fcs/gas-valve-pos-norm">
<function>
<sum>
<property>fcs/gas-valve-cmd-norm</property>
<property>ap/gas-valve-cmd-norm</property>
<product>
<value>100.0</value>
<property>fcs/ripped-sample-hold</property>
</product>
</sum>
</function>
<output>buoyant_forces/gas-cell/valve_open</output>
</fcs_function>

</channel>


<channel name="Ballonet air supply">

<fcs_function name="ballonets/slip-stream-pressure-psf">
<function>
<sum>
<property>atmosphere/P-psf</property>
<property>aero/qbar-psf</property>
<quotient>
<property>propulsion/engine/thrust-lbs</property>
<value>63.62</value> <!-- Propeller disc area ft^2 -->
</quotient>
</sum>
</function>
</fcs_function>

<fcs_function name="ballonets/crab-pot-valve-flow-ft3ps[0]">
<function>
<product>
<value>20.0</value> <!-- Inflow valve coefficient ft4*sec/slug -->
<max>
<value>0.0</value>
<product>
<property>fcs/ballonet-crabpot-valve-cmd-norm[0]</property>
<difference>
<property>ballonets/slip-stream-pressure-psf</property>
<property>buoyant_forces/gas-cell/ballonet[0]/pressure-psf</property>
</difference>
</product>
</max>
</product>
</function>
<output>ballonets/in-flow-ft3ps[0]</output>
</fcs_function>

<fcs_function name="ballonets/crab-pot-valve-flow-ft3ps[1]">
<function>
<product>
<value>20.0</value> <!-- Inflow valve coefficient ft4*sec/slug -->
<max>
<value>0.0</value>
<product>
<property>fcs/ballonet-crabpot-valve-cmd-norm[1]</property>
<difference>
<property>ballonets/slip-stream-pressure-psf</property>
<property>buoyant_forces/gas-cell/ballonet[1]/pressure-psf</property>
</difference>
</product>
</max>
</product>
</function>
<output>ballonets/in-flow-ft3ps[1]</output>
</fcs_function>

</channel>

<channel name="Ballonet out-flow valves">

<fcs_function name="ballonets/valve-pos-norm[0]">
<function>
<sum>
<property>fcs/ballonet-valve-cmd-norm[0]</property>
<property>ap/ballonet-valve-cmd-norm[0]</property>
</sum>
</function>
<output>buoyant_forces/gas-cell/ballonet[0]/valve_open</output>
</fcs_function>

<fcs_function name="ballonets/valve-pos-norm[1]">
<function>
<sum>
<property>fcs/ballonet-valve-cmd-norm[1]</property>
<property>ap/ballonet-valve-cmd-norm[1]</property>
</sum>
</function>
<output>buoyant_forces/gas-cell/ballonet[1]/valve_open</output>
</fcs_function>

</channel>

</system>

<flight_control name="Aerodynamic controls">
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