src/FDM/JSBSim/FGNozzle.cpp

   1 /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
   2
   3  Module:       FGNozzle.cpp
   4  Author:       Jon S. Berndt
   5  Date started: 08/24/00
   6  Purpose:      Encapsulates the nozzle object
   7
   8  ------------- Copyright (C) 2000  Jon S. Berndt (jsb@hal-pc.org) -------------
   9
  10  This program is free software; you can redistribute it and/or modify it under
  11  the terms of the GNU General Public License as published by the Free Software
  12  Foundation; either version 2 of the License, or (at your option) any later
  13  version.
  14
  15  This program is distributed in the hope that it will be useful, but WITHOUT
  16  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  17  FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
  18  details.
  19
  20  You should have received a copy of the GNU General Public License along with
  21  this program; if not, write to the Free Software Foundation, Inc., 59 Temple
  22  Place - Suite 330, Boston, MA  02111-1307, USA.
  23
  24  Further information about the GNU General Public License can also be found on
  25  the world wide web at http://www.gnu.org.
  26
  27 FUNCTIONAL DESCRIPTION
  28 --------------------------------------------------------------------------------
  29
  30 HISTORY
  31 --------------------------------------------------------------------------------
  32 08/24/00  JSB  Created
  33
  34 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  35 INCLUDES
  36 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
  37
  38 #include "FGNozzle.h"
  39
  40 static const char *IdSrc = "$Id$";
  41 static const char *IdHdr = ID_NOZZLE;
  42
  43 extern short debug_lvl;
  44
  45 /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  46 CLASS IMPLEMENTATION
  47 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
  48
  49
  50 FGNozzle::FGNozzle(FGFDMExec* FDMExec, FGConfigFile* Nzl_cfg) : FGThruster(FDMExec)
  51 {
  52   string token;
  53
  54   Name = Nzl_cfg->GetValue("NAME");
  55   Nzl_cfg->GetNextConfigLine();
  56   while (Nzl_cfg->GetValue() != "/FG_NOZZLE") {
  57     *Nzl_cfg >> token;
  58     if      (token == "PE")      *Nzl_cfg >> PE;
  59     else if (token == "EXPR")    *Nzl_cfg >> ExpR;
  60     else if (token == "NZL_EFF") *Nzl_cfg >> nzlEff;
  61     else if (token == "DIAM")    *Nzl_cfg >> Diameter;
  62     else cerr << "Unhandled token in Nozzle config file: " << token << endl;
  63   }
  64
  65   if (debug_lvl > 0) {
  66     cout << "      Nozzle Name: " << Name << endl;
  67     cout << "      Nozzle Exit Pressure = " << PE << endl;
  68     cout << "      Nozzle Expansion Ratio = " << ExpR << endl;
  69     cout << "      Nozzle Efficiency = " << nzlEff << endl;
  70     cout << "      Nozzle Diameter = " << Diameter << endl;
  71   }
  72
  73   Thrust = 0;
  74   Type = ttNozzle;
  75   Area2 = (Diameter*Diameter/4.0)*M_PI;
  76   AreaT = Area2/ExpR;
  77
  78   if (debug_lvl & 2) cout << "Instantiated: FGNozzle" << endl;
  79 }
  80
  81 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  82
  83 FGNozzle::~FGNozzle()
  84 {
  85   if (debug_lvl & 2) cout << "Destroyed:    FGNozzle" << endl;
  86 }
  87
  88 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  89
  90 float FGNozzle::Calculate(float CfPc)
  91 {
  92   float pAtm = fdmex->GetAtmosphere()->GetPressure();
  93   Thrust = (CfPc * AreaT + (PE - pAtm)*Area2) * nzlEff;
  94   vFn(1) = Thrust;
  95
  96   return Thrust;
  97 }
  98
  99 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 100
 101 float FGNozzle::GetPowerRequired(void)
 102 {
 103   return PE;
 104 }
 105
 106 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 107
 108 void FGNozzle::Debug(void)
 109 {
 110     //TODO: Add your source code here
 111 }
 112