USS_Monitor.xml

<?xml version="1.0"?>
<!--

  U.S.S. Monitor "flight" model for JSBSim.

    Copyright (C) 2012 - 2023  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
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.
  
    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.
  
    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  
-->
<?xml-stylesheet type="text/xsl" href="http://jsbsim.sourceforge.net/JSBSim.xsl"?>
<fdm_config name="USS_Monitor" version="2.0" release="ALPHA"
   xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
   xsi:noNamespaceSchemaLocation="http://jsbsim.sourceforge.net/JSBSim.xsd">

 <fileheader>
  <author>Anders Gidenstam</author>
  <email>anders at gidenstam dot org</email>

  <filecreationdate>2012-07-14</filecreationdate>
  <version>2023-12-25</version>

  <description>Models the U.S.S. Monitor / Ericsson Battery.</description>

  <license>
   <licenseName>GPL v2+</licenseName>
   <licenseURL>http://www.gnu.org/licenses/old-licenses/gpl-2.0.html</licenseURL>
  </license>
  <note>
   This model was created using publicly available data, publicly available
   technical reports, textbooks, and guesses. It contains no proprietary or
   restricted data. It has been validated only to the extent that it may seem
   to "fly right", and possibly to comply to published, publicly known, 
   performance data (maximum speed, endurance, etc.).

   This model is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
  </note>

  <reference refID="Miller:1974:PC"
             author="Edward M. Miller (ed.)"
             title="Project Cheesebox - A journey into history"
             date="1974"/>
  <reference refID="Peterkin:1985:DRM"
             author="Ernest W. Peterkin"
             title="Drawings of the U.S.S. Monitor"
             date="1985"/>
  <reference refID="Ripper:1909:HE"
             author="William Ripper"
             title="Heat Engines"
             date="1909"/>
  <reference refID="Ripper:1922:SE"
             author="William Ripper"
             title="Steam-Engine  Theory and Practice"
             date="1922"/>

 </fileheader>

 <documentation>
  The origin of the structural frame is at the bow of the ship 3.0 m above
  the hull datum line (at the bottom of the keel).
 </documentation>

 <metrics>
  <wingarea unit="FT2">     1510.0000  </wingarea> <!-- FIXME: update these -->
  <wingspan unit="FT">       114.0000  </wingspan>
  <chord unit="FT">           16.4583  </chord>
  <htailarea unit="FT2">     226.6750  </htailarea>
  <htailarm unit="FT">        12.2147  </htailarm>
  <vtailarea unit="FT2">     319.0423  </vtailarea>
  <vtailarm unit="FT">        17.2533  </vtailarm>
   <location name="AERORP" unit="M">
     <x> 25.45 </x>
     <y>  0.00 </y>
     <z>  0.00 </z>
   </location>
   <location name="EYEPOINT" unit="M">
     <x> 7.64 </x>
     <y> 1.58 </y>
     <z> 0.00 </z>
   </location>
   <location name="VRP" unit="M">
     <x> 0.00 </x>
     <y> 0.00 </y>
     <z>-3.00 </z>
   </location>
 </metrics>

 <mass_balance>
  <documentation>
   Information from ([Miller:1974:PC], pp.169, Letter by J. Ericsson 1861-09-15)
     Speed: Immersed section 312 ft^2, engine 400 hp, est. speed >=9 knots.

     Displacement: Total 2811200 lbs. With 18 in freeboard 2222080 lbs.

     Total weight of iron in vessel and turret: somewhat above 940800 lbs.

   Information from ([Miller:1974:PC], pp.145, Letter by J. Ericsson 1861-10-?)
     Displacement: Total 2881364 lbs.
     Launching draft: 6 ft 11 in (upper vessel immersed 5 in).
                      Displacement: 1172111 lbs.
     Weight of turret about 200000 lbs (to be added).

   Information from ([Peterkin:1985:DRM], drawing no. 154):
     Shear lines on commissioning:
     "The diagram indicates that the stern was 13 in above the water line,
     making the bow 32 in above the water line and the average freeboard
     amidships 22 1/2 in, 4 1/2 in above the design water line."

  </documentation>
  <documentation>
    Rough model to estimate CG and inertia tensor.

    % Steiners theorem:
    % Ixx = \bar{Ixx} + m sqrt(\bar{y}^2 + \bar{z}^2)
    % Ixy = \bar{Ixy} + m \bar{x} \bar{y}

    % The hull is a uniform 52.73x12.60x3.00 meter box.
    % CG in the middle (i.e. at (25.45, 0, -1)) m.
    m_hull = 0.45359237 * (1172111 - 40000) % KG
    a = 52.73    % m
    b = 12.60    % m
    c = 3.0      % m

    Ixx_hull = 1/12 * m_hull * (b^2 + c^2)
    Iyy_hull = 1/12 * m_hull * (a^2 + c^2)
    Izz_hull = 1/12 * m_hull * (a^2 + b^2)
    Ixy_hull = Ixz_hull = Iyz_hull = 0

    % The turret is a cylindrical shell with a diameter of 21ft and a
    % height of 9 ft weighing 200000 lbs with CG at (25.45, 0, 2)m in the
    % structural frame.
    m_turret = 0.45359237 * 200000 % KG
    h = 0.3048 * 9 % m
    r = 0.3048 * 10.5 % m
    Ixx_turret = 1/2 * m_turret * r^2 + 1/12 * m_turret * h^2 + \
                 m_turret * sqrt(0^2 + 3^2)
    Iyy_turret = Ixx_turret
    Izz_turret = m_turret * r^2
    Ixy_turret = Ixz_turret = Iyz_turret = 0


    Ixx = Ixx_hull + Ixx_turret
    Iyy = Iyy_hull + Iyy_turret
    Izz = Izz_hull + Izz_turret
    Ixy = Ixy_hull + Ixy_turret
    Ixz = Ixz_hull + Ixz_turret
    Iyz = Iyz_hull + Iyz_turret

  </documentation>
  <ixx unit="KG*M2">   7972600 </ixx>
  <iyy unit="KG*M2"> 120160000 </iyy>
  <izz unit="KG*M2"> 126710000 </izz>
  <emptywt unit="LBS" > 1332111 </emptywt>
  <location name="CG" unit="M">
   <x> 25.45 </x>
   <y>  0.00 </y>
   <z> -1.00 </z>
  </location>

  <documentation>
   Adjustable payload pointmasses.
  </documentation>

  <pointmass name="Port coal bunker">
   <weight unit="LBS"> 25000.0 </weight>
   <location unit="M">
    <x> 33.00 </x>
    <y> -3.50 </y>
    <z> -2.00 </z>
   </location>
  </pointmass>
  <pointmass name="Starboard coal bunker">
   <weight unit="LBS"> 25000.0 </weight>
   <location unit="M">
    <x> 33.00 </x>
    <y>  3.50 </y>
    <z> -2.00 </z>
   </location>
  </pointmass>

  <!-- A total of 2500 gallons according to the contract. [Miller:1974:PC] -->
  <pointmass name="Water in the port boiler">
   <weight unit="LBS"> 20000.0 </weight>
   <location unit="M">
    <x> 30.00 </x>
    <y> -1.50 </y>
    <z> -1.50 </z>
   </location>
  </pointmass>
  <pointmass name="Water in the starboard boiler">
   <weight unit="LBS"> 20000.0 </weight>
   <location unit="M">
    <x> 30.00 </x>
    <y>  1.50 </y>
    <z> -1.50 </z>
   </location>
  </pointmass>

  <pointmass name="Stores">
   <weight unit="LBS"> 20000.0 </weight>
   <location unit="M">
    <x> 10.00 </x>
    <y>  0.00 </y>
    <z> -2.50 </z>
   </location>
  </pointmass>

  <pointmass name="Ammunition">
   <weight unit="LBS"> 50000.0 </weight>
   <location unit="M">
    <x> 24.00 </x>
    <y>  0.00 </y>
    <z> -2.50 </z>
   </location>
  </pointmass>

  <!-- Movable weights. -->
  <!-- The 9in Dahlgren guns weighed about 15700lbs each.
       ([Peterkin:1985:DRM], p.500) -->
  <!-- Gun carriage: about 3200lbs (NOAA) -->
  <pointmass name="IX in. Dahlgren gun w. carriage">
   <weight unit="LBS"> 18900.0 </weight>
   <location unit="M">
    <x> 24.450 </x>
    <y> -0.762 </y>
    <z>  1.650 </z>
   </location>
  </pointmass>
  <pointmass name="IX in. Dahlgren gun w. carriage">
   <weight unit="LBS"> 18900.0 </weight>
   <location unit="M">
    <x> 24.450 </x>
    <y> -0.762 </y>
    <z>  1.650 </z>
   </location>
  </pointmass>

  <!-- Fixed weights. -->
  <pointmass name="Steam engine">
   <weight unit="LBS">40000.0</weight>
   <location unit="M">
    <x> 36.00 </x>
    <y>  0.00 </y>
    <z> -1.00 </z>
   </location>
  </pointmass>

 </mass_balance>

 <ground_reactions>
  <documentation>
   The hydrostatic interactions of the hull are modelled by external forces.
   Remove these in JSBSim/standalone.
  </documentation>

  <contact type="STRUCTURE" name="BOW">
   <location unit="M">
    <x>   0.00 </x>
    <y>   0.00 </y>
    <z>   2.00 </z>
   </location>
   <static_friction>  0.00 </static_friction>
   <dynamic_friction> 0.00 </dynamic_friction>
   <spring_coeff unit="LBS/FT">      200000.00 </spring_coeff>
   <damping_coeff unit="LBS/FT/SEC"> 150000.00 </damping_coeff>
  </contact>

  <contact type="STRUCTURE" name="STERN">
   <location unit="M">
    <x>  52.73 </x>
    <y>   0.00 </y>
    <z>   2.00 </z>
   </location>
   <static_friction>  0.00 </static_friction>
   <dynamic_friction> 0.00 </dynamic_friction>
   <spring_coeff unit="LBS/FT">      200000.00 </spring_coeff>
   <damping_coeff unit="LBS/FT/SEC"> 150000.00 </damping_coeff>
  </contact>

  <contact type="STRUCTURE" name="PORT SIDE">
   <location unit="M">
    <x>  25.45 </x>
    <y>  -6.30 </y>
    <z>   2.00 </z>
   </location>
   <static_friction>  0.00 </static_friction>
   <dynamic_friction> 0.00 </dynamic_friction>
   <spring_coeff unit="LBS/FT">      200000.00 </spring_coeff>
   <damping_coeff unit="LBS/FT/SEC"> 150000.00 </damping_coeff>
  </contact>
  <contact type="STRUCTURE" name="STARBOARD SIDE">
   <location unit="M">
    <x>  25.45 </x>
    <y>   6.30 </y>
    <z>   2.00 </z>
   </location>
   <static_friction>  0.00 </static_friction>
   <dynamic_friction> 0.00 </dynamic_friction>
   <spring_coeff unit="LBS/FT">      200000.00 </spring_coeff>
   <damping_coeff unit="LBS/FT/SEC"> 150000.00 </damping_coeff>
  </contact>

 </ground_reactions>

 <propulsion>
  <documentation>
   Will be modelled using external forces.
  </documentation>

 </propulsion>

 <external_reactions>

  <force name="hydro-X" frame="LOCAL" unit="LBS">
   <location unit="M">
    <x>  25.50 </x>
    <y>   0.00 </y>
    <z>   0.00 </z>
   </location>
   <direction>
    <x> 1.0 </x>
    <y> 0.0 </y>
    <z> 0.0 </z>
   </direction>
  </force>
  <force name="hydro-Y" frame="LOCAL" unit="LBS">
   <location unit="M">
    <x>  25.50 </x>
    <y>   0.00 </y>
    <z>   0.00 </z>
   </location>
   <direction>
    <x> 0.0 </x>
    <y> 1.0 </y>
    <z> 0.0 </z>
   </direction>
  </force>
  <force name="hydro-Z" frame="LOCAL" unit="LBS">
   <location unit="M">
    <x>  25.50 </x>
    <y>   0.00 </y>
    <z>   0.00 </z>
   </location>
   <direction>
    <x> 0.0 </x>
    <y> 0.0 </y>
    <z>-1.0 </z>
   </direction>
  </force>

  <moment name="hydro-pitch" frame="BODY" unit="LBSFT">
   <direction>
    <x> 0.0 </x>
    <y> 1.0 </y>
    <z> 0.0 </z>
   </direction>
  </moment>
  <moment name="hydro-roll" frame="BODY" unit="LBSFT">
   <direction>
    <x> 1.0 </x>
    <y> 0.0 </y>
    <z> 0.0 </z>
   </direction>
  </moment>
  <moment name="hydro-yaw" frame="BODY" unit="LBSFT">
   <direction>
    <x> 0.0 </x>
    <y> 0.0 </y>
    <z> 1.0 </z>
   </direction>
  </moment>

  <force name="propeller" frame="BODY" unit="LBS">
   <location unit="M">
    <x>  45.00 </x>
    <y>   0.00 </y>
    <z>  -1.80 </z>
   </location>
   <direction>
    <x> 1.0 </x>
    <y> 0.0 </y>
    <z> 0.0 </z>
   </direction>
  </force>


  <force name="mooring-north" frame="LOCAL" unit="LBS">
   <location unit="FT">
    <x> 3.3 </x>
    <y> 0.0 </y>
    <z> 0.0 </z>
   </location>
   <direction>
    <x> 1.0 </x>
    <y> 0.0 </y>
    <z> 0.0 </z>
   </direction>
  </force>
  <force name="mooring-east" frame="LOCAL" unit="LBS">
   <location unit="FT">
    <x> 3.3 </x>
    <y> 0.0 </y>
    <z> 0.0 </z>
   </location>
   <direction>
    <x> 0.0 </x>
    <y> 1.0 </y>
    <z> 0.0 </z>
   </direction>
  </force>
  <force name="mooring-down" frame="LOCAL" unit="LBS">
   <location unit="FT">
     <x> 3.3 </x>
     <y> 0.0 </y>
     <z> 0.0 </z>
   </location>
   <direction>
    <x> 1.0 </x>
    <y> 0.0 </y>
    <z> 0.0 </z>
   </direction>
  </force>

 </external_reactions>

 <system name="steering gear">

  <channel name="steering">

   <summer name="tmp/rudder-pos-norm">
    <input>fcs/rudder-cmd-norm</input>
    <input>-fcs/aileron-cmd-norm</input>
    <clipto>
     <min> -1 </min>
     <max>  1 </max>
    </clipto>
    <output>fcs/rudder-pos-norm</output>
   </summer>

  </channel>

 </system>

 <system file="hydrodynamics"/>
 <system file="USS_Monitor-hydrodynamics"/>
 <system file="propulsion"/>

 <!-- system file="fgfs4jsbsim" -->
 <!-- system file="mooring-jsbsim" -->    <!-- Mooring setup for FlightGear. -->
  <!-- Configuration -->
  <!--  Mooring rope -->
  <!-- property value="250.0"> mooring/rope-spring-coeff-lbs_ft </property>
  <property value="10000.0"> mooring/max-rope-force-lbs </property>
  <property value="20.0"> mooring/rope-length-ft </property>

 </system -->

 <aerodynamics>

  <axis name="DRAG">

   <!-- Wild guess: D = K A q_inf -->
   <!-- A = cross sectional area (ft^2); -->
   <function name="aero/force/D_turret">
    <description>Drag</description>
    <product>
     <property>aero/qbar-psf</property>
     <value> 193.5 </value>
     <!-- Start CD -->
     <value> 0.5 </value>
    </product>
   </function>
  </axis>

 </aerodynamics>

</fdm_config>