/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% Module: FGAtmosphere.cpp Author: Jon Berndt Implementation of 1959 Standard Atmosphere added by Tony Peden Date started: 11/24/98 Purpose: Models the atmosphere Called by: FGSimExec ------------- Copyright (C) 1999 Jon S. Berndt (jsb@hal-pc.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. Further information about the GNU General Public License can also be found on the world wide web at http://www.gnu.org. FUNCTIONAL DESCRIPTION -------------------------------------------------------------------------------- Models the atmosphere. The equation used below was determined by a third order curve fit using Excel. The data is from the ICAO atmosphere model. HISTORY -------------------------------------------------------------------------------- 11/24/98 JSB Created 07/23/99 TP Added implementation of 1959 Standard Atmosphere Moved calculation of Mach number to FGTranslation Later updated to '76 model %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% COMMENTS, REFERENCES, and NOTES %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% [1] Anderson, John D. "Introduction to Flight, Third Edition", McGraw-Hill, 1989, ISBN 0-07-001641-0 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% INCLUDES %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/ #include "FGAtmosphere.h" #include "FGState.h" #include "FGFDMExec.h" #include "FGFCS.h" #include "FGAircraft.h" #include "FGTranslation.h" #include "FGRotation.h" #include "FGPosition.h" #include "FGAuxiliary.h" #include "FGOutput.h" #include "FGMatrix33.h" #include "FGColumnVector3.h" #include "FGColumnVector4.h" #include "FGPropertyManager.h" static const char *IdSrc = "$Id$"; static const char *IdHdr = ID_ATMOSPHERE; /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% CLASS IMPLEMENTATION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/ FGAtmosphere::FGAtmosphere(FGFDMExec* fdmex) : FGModel(fdmex) { Name = "FGAtmosphere"; lastIndex = 0; h = 0.0; psiw = 0.0; htab[0]=0; htab[1]=36089.239; htab[2]=65616.798; htab[3]=104986.878; htab[4]=154199.475; htab[5]=170603.675; htab[6]=200131.234; htab[7]=259186.352; //ft. MagnitudedAccelDt = MagnitudeAccel = Magnitude = 0.0; turbType = ttNone; // turbType = ttBerndt; // temporarily disable turbulence until fully tested TurbGain = 100.0; bind(); Debug(0); } //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% FGAtmosphere::~FGAtmosphere() { unbind(); Debug(1); } //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% bool FGAtmosphere::InitModel(void) { FGModel::InitModel(); Calculate(h); SLtemperature = temperature; SLpressure = pressure; SLdensity = density; SLsoundspeed = sqrt(SHRatio*Reng*temperature); rSLtemperature = 1.0/temperature; rSLpressure = 1.0/pressure; rSLdensity = 1.0/density; rSLsoundspeed = 1.0/SLsoundspeed; useExternal=false; return true; } //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% bool FGAtmosphere::Run(void) { if (!FGModel::Run()) { // if false then execute this Run() //do temp, pressure, and density first if (!useExternal) { h = Position->Geth(); Calculate(h); } else { density = exDensity; pressure = exPressure; temperature = exTemperature; } if (turbType != ttNone) { Turbulence(); vWindNED += vTurbulence; } if (vWindNED(1) != 0.0) psiw = atan2( vWindNED(2), vWindNED(1) ); if (psiw < 0) psiw += 2*M_PI; soundspeed = sqrt(SHRatio*Reng*temperature); State->Seta(soundspeed); Debug(2); } else { // skip Run() execution this time } return false; } //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% // // See reference 1 void FGAtmosphere::Calculate(double altitude) { double slope, reftemp, refpress; int i = 0; i = lastIndex; if (altitude < htab[lastIndex]) { if (altitude <= 0) { i = 0; altitude=0; } else { i = lastIndex-1; while (htab[i] > altitude) i--; } } else if (altitude > htab[lastIndex+1]) { if (altitude >= htab[7]) { i = 7; altitude = htab[7]; } else { i = lastIndex+1; while (htab[i+1] < altitude) i++; } } switch(i) { case 1: // 36089 ft. slope = 0; reftemp = 389.97; refpress = 472.452; //refdens = 0.000706032; break; case 2: // 65616 ft. slope = 0.00054864; reftemp = 389.97; refpress = 114.636; //refdens = 0.000171306; break; case 3: // 104986 ft. slope = 0.00153619; reftemp = 411.57; refpress = 8.36364; //refdens = 1.18422e-05; break; case 4: // 154199 ft. slope = 0; reftemp = 487.17; refpress = 0.334882; //refdens = 4.00585e-7; break; case 5: // 170603 ft. slope = -0.00109728; reftemp = 487.17; refpress = 0.683084; //refdens = 8.17102e-7; break; case 6: // 200131 ft. slope = -0.00219456; reftemp = 454.17; refpress = 0.00684986; //refdens = 8.77702e-9; break; case 7: // 259186 ft. slope = 0; reftemp = 325.17; refpress = 0.000122276; //refdens = 2.19541e-10; break; case 0: default: // sea level slope = -0.00356616; // R/ft. reftemp = 518.67; // R refpress = 2116.22; // psf //refdens = 0.00237767; // slugs/cubic ft. break; } if (slope == 0) { temperature = reftemp; pressure = refpress*exp(-Inertial->SLgravity()/(reftemp*Reng)*(altitude-htab[i])); //density = refdens*exp(-Inertial->SLgravity()/(reftemp*Reng)*(altitude-htab[i])); density = pressure/(Reng*temperature); } else { temperature = reftemp+slope*(altitude-htab[i]); pressure = refpress*pow(temperature/reftemp,-Inertial->SLgravity()/(slope*Reng)); //density = refdens*pow(temperature/reftemp,-(Inertial->SLgravity()/(slope*Reng)+1)); density = pressure/(Reng*temperature); } lastIndex=i; //cout << "Atmosphere: h=" << altitude << " rho= " << density << endl; } //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% void FGAtmosphere::Turbulence(void) { switch (turbType) { case ttBerndt: vDirectiondAccelDt(eX) = 1 - 2.0*(((double)(rand()))/RAND_MAX); vDirectiondAccelDt(eY) = 1 - 2.0*(((double)(rand()))/RAND_MAX); vDirectiondAccelDt(eZ) = 1 - 2.0*(((double)(rand()))/RAND_MAX); MagnitudedAccelDt = 1 - 2.0*(((double)(rand()))/RAND_MAX); MagnitudeAccel += MagnitudedAccelDt*rate*State->Getdt(); Magnitude += MagnitudeAccel*rate*State->Getdt(); vDirectiondAccelDt.Normalize(); vDirectionAccel += vDirectiondAccelDt*rate*State->Getdt(); vDirectionAccel.Normalize(); vDirection += vDirectionAccel*rate*State->Getdt(); vDirection.Normalize(); vTurbulence = TurbGain*Magnitude * vDirection; vTurbulenceGrad = TurbGain*MagnitudeAccel * vDirection; vBodyTurbGrad = State->GetTl2b()*vTurbulenceGrad; vTurbPQR(eP) = vBodyTurbGrad(eY)/Aircraft->GetWingSpan(); if (Aircraft->GetHTailArm() != 0.0) vTurbPQR(eQ) = vBodyTurbGrad(eZ)/Aircraft->GetHTailArm(); else vTurbPQR(eQ) = vBodyTurbGrad(eZ)/10.0; if (Aircraft->GetVTailArm()) vTurbPQR(eR) = vBodyTurbGrad(eX)/Aircraft->GetVTailArm(); else vTurbPQR(eR) = vBodyTurbGrad(eX)/10.0; break; default: break; } } //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% void FGAtmosphere::bind(void) { typedef double (FGAtmosphere::*PMF)(int) const; PropertyManager->Tie("atmosphere/T-R", this, &FGAtmosphere::GetTemperature); PropertyManager->Tie("atmosphere/rho-slugs_ft3", this, &FGAtmosphere::GetDensity); PropertyManager->Tie("atmosphere/P-psf", this, &FGAtmosphere::GetPressure); PropertyManager->Tie("atmosphere/a-fps", this, &FGAtmosphere::GetSoundSpeed); PropertyManager->Tie("atmosphere/T-sl-R", this, &FGAtmosphere::GetTemperatureSL); PropertyManager->Tie("atmosphere/rho-sl-slugs_ft3", this, &FGAtmosphere::GetDensitySL); PropertyManager->Tie("atmosphere/P-sl-psf", this, &FGAtmosphere::GetPressureSL); PropertyManager->Tie("atmosphere/a-sl-fps", this, &FGAtmosphere::GetSoundSpeedSL); PropertyManager->Tie("atmosphere/theta-norm", this, &FGAtmosphere::GetTemperatureRatio); PropertyManager->Tie("atmosphere/sigma-norm", this, &FGAtmosphere::GetDensityRatio); PropertyManager->Tie("atmosphere/delta-norm", this, &FGAtmosphere::GetPressureRatio); PropertyManager->Tie("atmosphere/a-norm", this, &FGAtmosphere::GetSoundSpeedRatio); PropertyManager->Tie("atmosphere/psiw-rad", this, &FGAtmosphere::GetWindPsi); PropertyManager->Tie("atmosphere/p-turb-rad_sec", this,1, (PMF)&FGAtmosphere::GetTurbPQR); PropertyManager->Tie("atmosphere/q-turb-rad_sec", this,2, (PMF)&FGAtmosphere::GetTurbPQR); PropertyManager->Tie("atmosphere/r-turb-rad_sec", this,3, (PMF)&FGAtmosphere::GetTurbPQR); } //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% void FGAtmosphere::unbind(void) { PropertyManager->Untie("atmosphere/T-R"); PropertyManager->Untie("atmosphere/rho-slugs_ft3"); PropertyManager->Untie("atmosphere/P-psf"); PropertyManager->Untie("atmosphere/a-fps"); PropertyManager->Untie("atmosphere/T-sl-R"); PropertyManager->Untie("atmosphere/rho-sl-slugs_ft3"); PropertyManager->Untie("atmosphere/P-sl-psf"); PropertyManager->Untie("atmosphere/a-sl-fps"); PropertyManager->Untie("atmosphere/theta-norm"); PropertyManager->Untie("atmosphere/sigma-norm"); PropertyManager->Untie("atmosphere/delta-norm"); PropertyManager->Untie("atmosphere/a-norm"); PropertyManager->Untie("atmosphere/psiw-rad"); PropertyManager->Untie("atmosphere/p-turb-rad_sec"); PropertyManager->Untie("atmosphere/q-turb-rad_sec"); PropertyManager->Untie("atmosphere/r-turb-rad_sec"); } //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% // The bitmasked value choices are as follows: // unset: In this case (the default) JSBSim would only print // out the normally expected messages, essentially echoing // the config files as they are read. If the environment // variable is not set, debug_lvl is set to 1 internally // 0: This requests JSBSim not to output any messages // whatsoever. // 1: This value explicity requests the normal JSBSim // startup messages // 2: This value asks for a message to be printed out when // a class is instantiated // 4: When this value is set, a message is displayed when a // FGModel object executes its Run() method // 8: When this value is set, various runtime state variables // are printed out periodically // 16: When set various parameters are sanity checked and // a message is printed out when they go out of bounds void FGAtmosphere::Debug(int from) { if (debug_lvl <= 0) return; if (debug_lvl & 1) { // Standard console startup message output if (from == 0) { // Constructor } } if (debug_lvl & 2 ) { // Instantiation/Destruction notification if (from == 0) cout << "Instantiated: FGAtmosphere" << endl; if (from == 1) cout << "Destroyed: FGAtmosphere" << endl; } if (debug_lvl & 4 ) { // Run() method entry print for FGModel-derived objects } if (debug_lvl & 8 ) { // Runtime state variables } if (debug_lvl & 16) { // Sanity checking } if (debug_lvl & 32) { // Turbulence if (frame == 0 && from == 2) { cout << "vTurbulence(X), vTurbulence(Y), vTurbulence(Z), " << "vTurbulenceGrad(X), vTurbulenceGrad(Y), vTurbulenceGrad(Z), " << "vDirection(X), vDirection(Y), vDirection(Z), " << "Magnitude, " << "vTurbPQR(P), vTurbPQR(Q), vTurbPQR(R), " << endl; } else if (from == 2) { cout << vTurbulence << ", " << vTurbulenceGrad << ", " << vDirection << ", " << Magnitude << ", " << vTurbPQR << endl; } } if (debug_lvl & 64) { if (from == 0) { // Constructor cout << IdSrc << endl; cout << IdHdr << endl; } } }