MTB_20m.xml

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

  Swedish Navy 20m-class motor torpedo boat "flight" model for JSBSim.

    Copyright (C) 2012 - 2018  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="MTB_20m" 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>2012-09-29</filecreationdate>
  <version>2018-11-30</version>

  <description>Models a Swedish Navy 20m T21 class motor torpedo boat.</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="BorgenstamNyman:1981:MTB"
             author="Curt Borgenstam and Bo Nyman"
             title="Motortorpedbåt - En krönika i ord och bild om 'Havets flygande brigad'"
             date="1981"/>

  <reference refID="Wagner:1933:POW"
             author="Herbert Wagner"
             title="Planing of Watercraft  Translated as NACA-TM-1139"
             date="1933/1948"/>

 </fileheader>

 <documentation>
  The origin of the structural frame is at the bow of the ship.
  See the 3d model.
 </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> 12.00 </x>
    <y>  0.00 </y>
    <z>  0.00 </z>
   </location>
   <location name="EYEPOINT" unit="M">
    <x> 10.00 </x>
    <y>  2.00 </y>
    <z>  0.00 </z>
   </location>
   <location name="VRP" unit="M">
    <x> 0.00 </x>
    <y> 0.00 </y>
    <z> 0.00 </z>
   </location>
 </metrics>

 <mass_balance>
  <documentation>
   Information from ([BorgenstamNyman:1981:MTB], pp.254.)
     Length:       20.0m
     Displacement: 27000 kg

  </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 20.00x5.00x2.00 meter box.
    % CG in the middle (i.e. at (10, 0, -1)) m.
    m_hull = 9100 %0.7*(27000 - 6000 - 2*1500 - 2*2500 - 2*150) % KG
    a = 20.00    % m
    b = 5.0      % m
    c = 2.0      % 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

    Ixx = Ixx_hull
    Iyy = Iyy_hull
    Izz = Izz_hull
    Ixy = Ixy_hull
    Ixz = Ixz_hull
    Iyz = Iyz_hull
  </documentation>
  <ixx unit="KG*M2"> 2.1992e+04 </ixx>
  <iyy unit="KG*M2"> 3.0637e+05 </iyy>
  <izz unit="KG*M2"> 3.2229e+05 </izz>
  <emptywt unit="KG" > 9100 </emptywt>
  <location name="CG" unit="M">
   <x> 12.00 </x>
   <y>  0.00 </y>
   <z> -1.00 </z>
  </location>

  <documentation>
   Adjustable payload pointmasses.

   No specific details on the torpedoes have been found.
   The following data from [http://www.navweaps.com/Weapons/WTBR_PreWWII.php]
   is for a British 21" Mark IV torpedo which may well be somewhat similar
   (it was used throughout WWI and WWII):
     Date Of Design     About 1912
     Date In Service    About 1916
     Weight             3,206 lbs. (1,454 kg)
     Overall Length     22 ft 7.5 in (6.896 m)
     Explosive Charge   515 lbs. (234 kg) TNT
     Range / Speed      8,000 yards (7,300 m) / 35 knots
                        10,000 yards (9,150 m) / 29 knots
                        13,500 yards (12,350 m) / 25 knots
                        World War II Submarines, only:
                        6,000 yards (5,500 m) / 40 knots
                        9,500 yards (8,700 m) / 35 knots
     Power              Wet-heater
   The later 21" Mark V was somewhat longer and heavier:
     Date Of Design     About 1917
     Date In Service    1918
     Weight             3,828 lbs. (1,736 kg)
     Overall Length     23 ft 3 in (7.086 m)
     Explosive Charge   N/A
     Range / Speed      5,000 yards (4,570 m) / 40 knots
                        13,500 yards (12,340 m) / 25 knots
     Power              Wet-heater
   The torpedo tubes do not allow torpedoes longer than about 7 m.
  </documentation>

  <pointmass name="Port torpedo">
   <weight unit="KG"> 1500.0 </weight> <!-- 1800kg for Torped 61, 1965- -->
   <location unit="M">
    <x> 11.52 </x>
    <y> -1.60 </y>
    <z>  0.60 </z>
   </location>
  </pointmass>
  <pointmass name="Starboard torpedo">
   <weight unit="KG"> 1500.0 </weight>
   <location unit="M">
    <x> 11.52 </x>
    <y>  1.60 </y>
    <z>  0.60 </z>
   </location>
  </pointmass>

  <pointmass name="Fore debug trim weight">
   <weight unit="LBS">500.0</weight>
   <location unit="M">
    <x>  2.00 </x>
    <y>  0.00 </y>
    <z> -1.00 </z>
   </location>
  </pointmass>
  <pointmass name="Aft debug trim weight">
   <weight unit="LBS">500.0</weight>
   <location unit="M">
    <x>  20.00 </x>
    <y>   0.00 </y>
    <z>  -1.00 </z>
   </location>
  </pointmass>

  <!-- Fixed weights. -->
  <pointmass name="Port torpedo tube">
   <weight unit="KG"> 250.0 </weight>
   <location unit="M">
    <x> 11.52 </x>
    <y> -1.60 </y>
    <z>  0.60 </z>
   </location>
  </pointmass>
  <pointmass name="Starboard torpedo tube">
   <weight unit="KG"> 250.0 </weight>
   <location unit="M">
    <x> 11.52 </x>
    <y>  1.60 </y>
    <z>  0.60 </z>
   </location>
  </pointmass>

  <pointmass name="Port engine">
   <weight unit="KG">1500.0</weight>
   <location unit="M">
    <x> 12.00 </x>
    <y> -1.00 </y>
    <z> -1.00 </z>
   </location>
  </pointmass>

  <pointmass name="Starboard engine">
   <weight unit="LBS">1500.0</weight>
   <location unit="M">
    <x> 12.00 </x>
    <y>  1.00 </y>
    <z> -1.00 </z>
   </location>
  </pointmass>

  <pointmass name="Port auxiliary engine">
   <weight unit="KG">150.0</weight>
   <location unit="M">
    <x> 14.00 </x>
    <y> -1.00 </y>
    <z> -1.00 </z>
   </location>
  </pointmass>

  <pointmass name="Starboard auxiliary engine">
   <weight unit="LBS">150.0</weight>
   <location unit="M">
    <x> 14.00 </x>
    <y>  1.00 </y>
    <z> -1.00 </z>
   </location>
  </pointmass>

 </mass_balance>

 <ground_reactions>
  <documentation>
   The hydrostatic interactions of the hull are modelled by external forces.
  </documentation>

  <contact type="BOGEY" name="BOW">
   <location unit="M">
    <x>   1.00 </x>
    <y>   0.00 </y>
    <z>  -1.70 </z>
   </location>
   <static_friction>  0.70 </static_friction>
   <dynamic_friction> 0.60 </dynamic_friction>
   <rolling_friction> 0.30 </rolling_friction>
   <spring_coeff unit="LBS/FT">      20000.00 </spring_coeff>
   <damping_coeff unit="LBS/FT/SEC"> 15000.00 </damping_coeff>
  </contact>

  <contact type="BOGEY" name="STEP">
   <location unit="M">
    <x>   8.00 </x>
    <y>   0.00 </y>
    <z>  -2.30 </z>
   </location>
   <static_friction>  0.70 </static_friction>
   <dynamic_friction> 0.60 </dynamic_friction>
   <rolling_friction> 0.30 </rolling_friction>
   <spring_coeff unit="LBS/FT">      20000.00 </spring_coeff>
   <damping_coeff unit="LBS/FT/SEC"> 15000.00 </damping_coeff>
  </contact>

  <contact type="BOGEY" name="STERN">
   <location unit="M">
    <x>  20.00 </x>
    <y>   0.00 </y>
    <z>  -2.05 </z>
   </location>
   <static_friction>  0.70 </static_friction>
   <dynamic_friction> 0.60 </dynamic_friction>
   <rolling_friction> 0.30 </rolling_friction>
   <spring_coeff unit="LBS/FT">      20000.00 </spring_coeff>
   <damping_coeff unit="LBS/FT/SEC"> 15000.00 </damping_coeff>
  </contact>

  <contact type="STRUCTURE" name="PORT CHINE">
   <location unit="M">
    <x>  7.00 </x>
    <y> -2.50 </y>
    <z> -1.90 </z>
   </location>
   <static_friction>  0.70 </static_friction>
   <dynamic_friction> 0.60 </dynamic_friction>
   <spring_coeff unit="LBS/FT">      20000.00 </spring_coeff>
   <damping_coeff unit="LBS/FT/SEC"> 15000.00 </damping_coeff>
  </contact>
  <contact type="STRUCTURE" name="STARBOARD CHINE">
   <location unit="M">
    <x>  7.00 </x>
    <y>  2.50 </y>
    <z> -1.90 </z>
   </location>
   <static_friction>  0.70 </static_friction>
   <dynamic_friction> 0.60 </dynamic_friction>
   <spring_coeff unit="LBS/FT">      20000.00 </spring_coeff>
   <damping_coeff unit="LBS/FT/SEC"> 15000.00 </damping_coeff>
  </contact>

 </ground_reactions>

 <propulsion>
  <documentation>
  </documentation>
  <!--
  === Engine ================================================
  -->
  <!-- Port main engine -->
  <engine file="eng_IsottaFraschini_IF184">
   <location unit="M">
    <x>  12.0 </x>
    <y>  -1.0 </y>
    <z>  -1.0 </z>
   </location>
   <orient unit="DEG">
    <roll>  0.0 </roll>
    <pitch> 0.0 </pitch>
    <yaw>   0.0 </yaw>
   </orient>
   <feed>0</feed>
   <feed>1</feed>
   <thruster file="prop_MTB_20m">
    <location unit="M">
     <x>  19.7 </x>
     <y>  -1.0 </y>
     <z>  -2.4 </z>
    </location>
    <orient unit="DEG">
     <roll>  0.0 </roll>
     <pitch> 0.0 </pitch>
     <yaw>   0.0 </yaw>
    </orient>
   </thruster>
  </engine>

  <!-- Starboard main engine -->
  <engine file="eng_IsottaFraschini_IF184">
   <location unit="M">
    <x>  12.0 </x>
    <y>   1.0 </y>
    <z>  -1.0 </z>
   </location>
   <orient unit="DEG">
    <roll>  0.0 </roll>
    <pitch> 0.0 </pitch>
    <yaw>   0.0 </yaw>
   </orient>
   <feed>0</feed>
   <feed>1</feed>
   <thruster file="prop_MTB_20m">
    <location unit="M">
     <x>  19.7 </x>
     <y>   1.0 </y>
     <z>  -2.4 </z>
    </location>
    <orient unit="DEG">
     <roll>  0.0 </roll>
     <pitch> 0.0 </pitch>
     <yaw>   0.0 </yaw>
    </orient>
   </thruster>
  </engine>

  <!-- Port auxiliary engine -->
  <engine file="eng_FordV8-48">
   <location unit="M">
    <x>  14.0 </x>
    <y>  -1.0 </y>
    <z>  -1.2 </z>
   </location>
   <orient unit="DEG">
    <roll>  0.0 </roll>
    <pitch> 0.0 </pitch>
    <yaw>   0.0 </yaw>
   </orient>
   <feed>0</feed>
   <feed>1</feed>
   <thruster file="prop_MTB_20m">
    <location unit="M">
     <x>  19.7 </x>
     <y>  -1.0 </y>
     <z>  -2.4 </z>
    </location>
    <orient unit="DEG">
     <roll>  0.0 </roll>
     <pitch> 0.0 </pitch>
     <yaw>   0.0 </yaw>
    </orient>
   </thruster>
  </engine>

  <!-- Starboard auxiliary engine -->
  <engine file="eng_FordV8-48">
   <location unit="M">
    <x>  14.0 </x>
    <y>   1.0 </y>
    <z>  -1.2 </z>
   </location>
   <orient unit="DEG">
    <roll>  0.0 </roll>
    <pitch> 0.0 </pitch>
    <yaw>   0.0 </yaw>
   </orient>
   <feed>0</feed>
   <feed>1</feed>
   <thruster file="prop_MTB_20m">
    <location unit="M">
     <x>  19.7 </x>
     <y>   1.0 </y>
     <z>  -2.4 </z>
    </location>
    <orient unit="DEG">
     <roll>  0.0 </roll>
     <pitch> 0.0 </pitch>
     <yaw>   0.0 </yaw>
    </orient>
   </thruster>
  </engine>

  <!--
  === Fuel tanks ============================================
  -->
  <documentation>
  </documentation>

  <tank type="FUEL">
   <location unit="M">
    <x> 17.0 </x>
    <y> -1.0</y>
    <z> -1.0 </z>
   </location>
   <capacity unit="KG"> 3000.0 </capacity>
   <contents unit="KG"> 3000.0 </contents>
  </tank>
  <tank type="FUEL">
   <location unit="M">
    <x> 17.0 </x>
    <y>  1.0</y>
    <z> -1.0 </z>
   </location>
   <capacity unit="KG"> 3000.0 </capacity>
   <contents unit="KG"> 3000.0 </contents>
  </tank>

 </propulsion>

 <external_reactions>

  <documentation>
   HRP: 12, 0, 0 m
  </documentation>

  <force name="hydro-X" frame="LOCAL" unit="LBS">
   <location unit="M">
    <x>  12.00 </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>  12.00 </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>  12.00 </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[0]" frame="BODY" unit="LBS">
   <location unit="M">
    <x>  19.7 </x>
    <y>  -1.0 </y>
    <z>  -2.4 </z>
   </location>
   <direction>
    <x> 1.0 </x>
    <y> 0.0 </y>
    <z> 0.0 </z>
   </direction>
  </force>
  <force name="propeller[1]" frame="BODY" unit="LBS">
   <location unit="M">
    <x>  19.7 </x>
    <y>   1.0 </y>
    <z>  -2.4 </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> 0.0 </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> 0.0 </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> 0.0 </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 file="hydrodynamics"/>
 <system file="hydrodynamic-planing">
  <!-- Parameters defining the planing surfaces of the hull. -->
  <!-- NOTE: Coordinates in the hydro RP frame. -->
  <property value="27.20">hydro/planing/forebody-length-ft</property>
  <property value="14.76">hydro/planing/forebody-beam-ft</property>
  <property value="-7.28">hydro/planing/forebody-keel-z-ft</property>
  <property value="-12.17">hydro/planing/forebody-end-x-ft</property>

  <property value="11.06">hydro/planing/middlebody-length-ft</property>
  <property value="14.76">hydro/planing/middlebody-beam-ft</property>
  <property value="-6.96">hydro/planing/middlebody-keel-z-ft</property>
  <property value="-0.98">hydro/planing/middlebody-end-x-ft</property>

  <property value="25.39">hydro/planing/afterbody-length-ft</property>
  <property value="11.54">hydro/planing/afterbody-beam-ft</property>
  <property value="-6.56">hydro/planing/afterbody-keel-z-ft</property>
  <property value="26.25">hydro/planing/afterbody-end-x-ft</property>

  <property value="0.95">hydro/planing/forebody-normal-force-factor</property>
  <property value="0.90">hydro/planing/middlebody-normal-force-factor</property>
  <property value="0.85">hydro/planing/afterbody-normal-force-factor</property>

  <!-- FIXME: Replace with Reynolds number based coefficient?
  -->
  <property value="0.001">hydro/planing/forebody-skin-friction-coefficient</property>
  <property value="0.001">hydro/planing/middlebody-skin-friction-coefficient</property>
  <property value="0.001">hydro/planing/afterbody-skin-friction-coefficient</property>

 </system>
 <system file="MTB_20m-hydrodynamics"/>
 <system file="MTB_20m-ground_reactions"/>
 <system file="propulsion"/>

 <system name="steering gear">

  <channel name="steering">

   <fcs_function name="tmp/rudder-pos-norm">
    <function>
     <product>
      <table>
       <independentVar lookup="row">hydro/v-kt</independentVar>
       <tableData>
         0.0  1.0
        50.0  0.3
       </tableData>
      </table>
      <difference>
       <property>fcs/rudder-cmd-norm</property>
       <property>fcs/aileron-cmd-norm</property>
      </difference>
     </product>
    </function>
    <clipto>
     <min> -1 </min>
     <max>  1 </max>
    </clipto>
    <output>fcs/rudder-pos-norm</output>
   </fcs_function>

  </channel>

 </system>

 <!-- 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"> <!-- FIXME! -->

   <!-- Wild guess: D = K A q_inf -->
   <!-- A = cross sectional area (ft^2); -->
   <function name="aero/force/D_hull">
    <description>Drag</description>
    <product>
     <property>aero/qbar-psf</property>
     <value> 100.0 </value>
     <!-- Start CD -->
     <value> 0.5 </value>
     <product>  <!-- Increase drag with beta. -->
      <value>5.0</value>
      <abs><sin><property>aero/beta-rad</property></sin></abs>
     </product>
    </product>
   </function>
  </axis>

 </aerodynamics>

</fdm_config>