[Jsbsim-cvslogs] CVS: JSBSim/utils/aeromatic++/Systems Propulsion.cpp, 1.15, 1.16 Propulsion.h, 1.5, 1.6

[Erik H. <eh...@us...>]

Update of /cvsroot/jsbsim/JSBSim/utils/aeromatic++/Systems
In directory sfp-cvs-1.v30.ch3.sourceforge.com:/tmp/cvs-serv10827/Systems

Modified Files:
	Propulsion.cpp Propulsion.h 
Log Message:
Fix LBS_TO_KG and add a proper estimation of psfc

Index: Propulsion.cpp
===================================================================
RCS file: /cvsroot/jsbsim/JSBSim/utils/aeromatic++/Systems/Propulsion.cpp,v
retrieving revision 1.15
retrieving revision 1.16
diff -C2 -r1.15 -r1.16
*** Propulsion.cpp	23 Oct 2015 14:18:10 -0000	1.15
--- Propulsion.cpp	24 Oct 2015 11:51:13 -0000	1.16
***************
*** 615,618 ****
--- 615,619 ----
  TurbopropEngine::TurbopropEngine(Aeromatic *a, Propulsion *p) : Engine(a, p),
      _max_rpm(2700.0f),
+     _oapr(15.0f),
      _itt(800.0f),
      _psfc(0.66f),
***************
*** 622,631 ****
      _inputs.push_back(new Param("Engine Power", 0, _power, _aircraft->_metric, POWER));
      _inputs.push_back(new Param("Maximum Engine RPM", 0, _max_rpm));
      _inputs.push_back(new Param("Inlet Turbine Temperature", Aeromatic::_estimate, _itt));
      _thruster = new Propeller(this);
  }
  
! // http://www.aerocompinc.com/ftp/literature/walter601.pdf
! // http://www.smartcockpit.com/docs/Fokker_50-Power_Plant.pdf
  std::string TurbopropEngine::engine()
  {
--- 623,642 ----
      _inputs.push_back(new Param("Engine Power", 0, _power, _aircraft->_metric, POWER));
      _inputs.push_back(new Param("Maximum Engine RPM", 0, _max_rpm));
+     _inputs.push_back(new Param("Overall pressure ratio", Aeromatic::_estimate, _oapr));
      _inputs.push_back(new Param("Inlet Turbine Temperature", Aeromatic::_estimate, _itt));
      _thruster = new Propeller(this);
  }
  
! // http://www.fzt.haw-hamburg.de/pers/Scholz/Airport2030/Airport2030_PUB_ICAS_12-09-23.pdf
! //
! // _power is in kW for the following computations:
! // _oapr = overall  pressure ratio at static sea level 
! // Ttet = turbine  entry  temperature at static sea level in Kelvin
! //
! // mass_eng = 0.246f * _power;
! // eng_length = 0.1068f * powf(_power, 0.4094f);
! // eng_diameter = 0.1159f * powf(_power, 0.2483f);
! // psfc = 2.56*10e-4 - logf(_power * _oapr * Ttet)*10e-5;
! 
  std::string TurbopropEngine::engine()
  {
***************
*** 638,641 ****
--- 649,659 ----
      float psfc = 0.5f;
  
+     // calculate psfc in KG/SEC/KW
+     float Ttet = _itt + 274.15f;	// in Kelvin
+     psfc = 2.56e-4f - logf(_power*HP_TO_KW * _oapr * Ttet)*1e-5f;
+ 
+     // Convert psfc to LBS/HR/HP
+     psfc *= 5918.3525f;
+ 
      // estimate thrust if given power in HP
      float thrust = _power * 2.24f;

Index: Propulsion.h
===================================================================
RCS file: /cvsroot/jsbsim/JSBSim/utils/aeromatic++/Systems/Propulsion.h,v
retrieving revision 1.5
retrieving revision 1.6
diff -C2 -r1.5 -r1.6
*** Propulsion.h	23 Oct 2015 12:33:29 -0000	1.5
--- Propulsion.h	24 Oct 2015 11:51:13 -0000	1.6
***************
*** 91,94 ****
--- 91,95 ----
  public:
      float _max_rpm;
+     float _oapr;
      float _itt;
      float _psfc;