-/*******************************************************************************
+/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
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
HISTORY
--------------------------------------------------------------------------------
11/24/98 JSB Created
+07/23/99 TP Added implementation of 1959 Standard Atmosphere
+ Moved calculation of Mach number to FGTranslation
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+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 "FGPosition.h"
#include "FGAuxiliary.h"
#include "FGOutput.h"
+#include "FGMatrix33.h"
+#include "FGColumnVector3.h"
+#include "FGColumnVector4.h"
+
+static const char *IdSrc = "$Id$";
+static const char *IdHdr = ID_ATMOSPHERE;
+
+/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+CLASS IMPLEMENTATION
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
-/*******************************************************************************
-************************************ CODE **************************************
-*******************************************************************************/
FGAtmosphere::FGAtmosphere(FGFDMExec* fdmex) : FGModel(fdmex)
{
Name = "FGAtmosphere";
+ lastIndex=0;
+ h = 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;
+
+ Debug(0);
}
+//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
FGAtmosphere::~FGAtmosphere()
{
+ 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()
- rho = 0.002377 - 7.0E-08*State->Geth()
- + 7.0E-13*State->Geth()*State->Geth()
- - 2.0E-18*State->Geth()*State->Geth()*State->Geth();
+ //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);
- State->SetMach(State->GetVt()/State->Geta());
} 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;
+ }
+}
+
+//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+// 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;
+ }
+ }
+}
+