Module: FGAtmosphere.cpp
Author: Jon Berndt
- Implementation of 1959 Standard Atmosphere added by Tony Peden
+ Implementation of 1959 Standard Atmosphere added by Tony Peden
Date started: 11/24/98
Purpose: Models the atmosphere
Called by: FGSimExec
--------------------------------------------------------------------------------
11/24/98 JSB Created
07/23/99 TP Added implementation of 1959 Standard Atmosphere
- Moved calculation of Mach number to FGTranslation
+ Moved calculation of Mach number to FGPropagate
+ Later updated to '76 model
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COMMENTS, REFERENCES, and NOTES
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#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 "FGPropagate.h"
+#include "FGInertial.h"
#include "FGPropertyManager.h"
+namespace JSBSim {
+
static const char *IdSrc = "$Id$";
static const char *IdHdr = ID_ATMOSPHERE;
FGAtmosphere::FGAtmosphere(FGFDMExec* fdmex) : FGModel(fdmex)
{
Name = "FGAtmosphere";
- lastIndex=0;
- h = 0;
+ lastIndex = 0;
+ h = 0.0;
+ psiw = 0.0;
htab[0]=0;
htab[1]=36089.239;
htab[2]=65616.798;
htab[7]=259186.352; //ft.
MagnitudedAccelDt = MagnitudeAccel = Magnitude = 0.0;
- turbType = ttNone;
-// turbType = ttBerndt; // temporarily disable turbulence until fully tested
- TurbGain = 100.0;
-
+// turbType = ttNone;
+ turbType = ttStandard;
+// turbType = ttBerndt;
+ TurbGain = 0.0;
+ TurbRate = 1.0;
+
+ T_dev_sl = T_dev = delta_T = 0.0;
+
bind();
Debug(0);
}
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;
+ SLtemperature = intTemperature;
+ SLpressure = intPressure;
+ SLdensity = intDensity;
+ SLsoundspeed = sqrt(SHRatio*Reng*intTemperature);
+ rSLtemperature = 1.0/intTemperature;
+ rSLpressure = 1.0/intPressure;
+ rSLdensity = 1.0/intDensity;
rSLsoundspeed = 1.0/SLsoundspeed;
+ temperature=&intTemperature;
+ pressure=&intPressure;
+ density=&intDensity;
+
useExternal=false;
-
+
return true;
}
if (!FGModel::Run()) { // if false then execute this Run()
//do temp, pressure, and density first
if (!useExternal) {
- h = Position->Geth();
+ h = Propagate->Geth();
Calculate(h);
- } else {
- density = exDensity;
- pressure = exPressure;
- temperature = exTemperature;
}
if (turbType != ttNone) {
if (psiw < 0) psiw += 2*M_PI;
- soundspeed = sqrt(SHRatio*Reng*temperature);
-
- State->Seta(soundspeed);
+ soundspeed = sqrt(SHRatio*Reng*(*temperature));
Debug(2);
+ return false;
} else { // skip Run() execution this time
+ return true;
}
-
- return false;
}
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
i = lastIndex;
if (altitude < htab[lastIndex]) {
- if (altitude <= 0) {
+ 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]){
+ }
+ } 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++;
- }
- }
+ while (htab[i+1] < altitude) i++;
+ }
+ }
switch(i) {
case 1: // 36089 ft.
refpress = 2116.22; // psf
//refdens = 0.00237767; // slugs/cubic ft.
break;
-
+
}
-
+
+ T_dev = 0.0;
+ if (delta_T != 0.0) {
+ T_dev = delta_T;
+ } else {
+ if ((h < 36089.239) && (T_dev_sl != 0.0)) {
+ T_dev = T_dev_sl * ( 1.0 - (h/36089.239));
+ }
+ }
+ density_altitude = h + T_dev * 66.7;
+
+ reftemp+=T_dev;
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);
+ intTemperature = reftemp;
+ intPressure = refpress*exp(-Inertial->SLgravity()/(reftemp*Reng)*(altitude-htab[i]));
+ //intDensity = refdens*exp(-Inertial->SLgravity()/(reftemp*Reng)*(altitude-htab[i]));
+ intDensity = intPressure/(Reng*intTemperature);
} 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);
+ intTemperature = reftemp+slope*(altitude-htab[i]);
+ intPressure = refpress*pow(intTemperature/reftemp,-Inertial->SLgravity()/(slope*Reng));
+ //intDensity = refdens*pow(intTemperature/reftemp,-(Inertial->SLgravity()/(slope*Reng)+1));
+ intDensity = intPressure/(Reng*intTemperature);
}
lastIndex=i;
- //cout << "Atmosphere: h=" << altitude << " rho= " << density << endl;
+ //cout << "Atmosphere: h=" << altitude << " rho= " << intDensity << endl;
+}
+
+//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+// Return the pressure at an arbitrary altitude and then restore the internal state
+
+double FGAtmosphere::GetPressure(double alt) {
+ Calculate(alt);
+ double p = *pressure;
+ // Reset the internal atmospheric state
+ Run();
+ return(p);
+}
+
+//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+// square a value, but preserve the original sign
+
+static inline double square_signed (double value)
+{
+ if (value < 0)
+ return value * value * -1;
+ else
+ return value * value;
}
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
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);
+ case ttStandard: {
+ vDirectiondAccelDt(eX) = 1 - 2.0*(double(rand())/double(RAND_MAX));
+ vDirectiondAccelDt(eY) = 1 - 2.0*(double(rand())/double(RAND_MAX));
+ vDirectiondAccelDt(eZ) = 1 - 2.0*(double(rand())/double(RAND_MAX));
+
+ MagnitudedAccelDt = 1 - 2.0*(double(rand())/double(RAND_MAX)) - Magnitude;
+ // Scale the magnitude so that it moves
+ // away from the peaks
+ MagnitudedAccelDt = ((MagnitudedAccelDt - Magnitude) /
+ (1 + fabs(Magnitude)));
+ MagnitudeAccel += MagnitudedAccelDt*rate*TurbRate*State->Getdt();
+ Magnitude += MagnitudeAccel*rate*State->Getdt();
+
+ vDirectiondAccelDt.Normalize();
+
+ // deemphasise non-vertical forces
+ vDirectiondAccelDt(eX) = square_signed(vDirectiondAccelDt(eX));
+ vDirectiondAccelDt(eY) = square_signed(vDirectiondAccelDt(eY));
- MagnitudedAccelDt = 1 - 2.0*(((double)(rand()))/RAND_MAX);
+ vDirectionAccel += vDirectiondAccelDt*rate*TurbRate*State->Getdt();
+ vDirectionAccel.Normalize();
+ vDirection += vDirectionAccel*rate*State->Getdt();
+
+ vDirection.Normalize();
+
+ // Diminish turbulence within three wingspans
+ // of the ground
+ vTurbulence = TurbGain * Magnitude * vDirection;
+ double HOverBMAC = Auxiliary->GetHOverBMAC();
+ if (HOverBMAC < 3.0)
+ vTurbulence *= (HOverBMAC / 3.0) * (HOverBMAC / 3.0);
+
+ vTurbulenceGrad = TurbGain*MagnitudeAccel * vDirection;
+
+ vBodyTurbGrad = Propagate->GetTl2b()*vTurbulenceGrad;
+
+ if (Aircraft->GetWingSpan() > 0) {
+ vTurbPQR(eP) = vBodyTurbGrad(eY)/Aircraft->GetWingSpan();
+ } else {
+ vTurbPQR(eP) = vBodyTurbGrad(eY)/30.0;
+ }
+// if (Aircraft->GetHTailArm() != 0.0)
+// vTurbPQR(eQ) = vBodyTurbGrad(eZ)/Aircraft->GetHTailArm();
+// else
+// vTurbPQR(eQ) = vBodyTurbGrad(eZ)/10.0;
+
+ if (Aircraft->GetVTailArm() > 0)
+ vTurbPQR(eR) = vBodyTurbGrad(eX)/Aircraft->GetVTailArm();
+ else
+ vTurbPQR(eR) = vBodyTurbGrad(eX)/10.0;
+
+ // Clear the horizontal forces
+ // actually felt by the plane, now
+ // that we've used them to calculate
+ // moments.
+ vTurbulence(eX) = 0.0;
+ vTurbulence(eY) = 0.0;
+
+ break;
+ }
+ case ttBerndt: {
+ vDirectiondAccelDt(eX) = 1 - 2.0*(double(rand())/double(RAND_MAX));
+ vDirectiondAccelDt(eY) = 1 - 2.0*(double(rand())/double(RAND_MAX));
+ vDirectiondAccelDt(eZ) = 1 - 2.0*(double(rand())/double(RAND_MAX));
+
+
+ MagnitudedAccelDt = 1 - 2.0*(double(rand())/double(RAND_MAX)) - Magnitude;
MagnitudeAccel += MagnitudedAccelDt*rate*State->Getdt();
Magnitude += MagnitudeAccel*rate*State->Getdt();
vDirectionAccel += vDirectiondAccelDt*rate*State->Getdt();
vDirectionAccel.Normalize();
vDirection += vDirectionAccel*rate*State->Getdt();
+
+ // Diminish z-vector within two wingspans
+ // of the ground
+ double HOverBMAC = Auxiliary->GetHOverBMAC();
+ if (HOverBMAC < 2.0)
+ vDirection(eZ) *= HOverBMAC / 2.0;
+
vDirection.Normalize();
-
+
vTurbulence = TurbGain*Magnitude * vDirection;
vTurbulenceGrad = TurbGain*MagnitudeAccel * vDirection;
- vBodyTurbGrad = State->GetTl2b()*vTurbulenceGrad;
+ vBodyTurbGrad = Propagate->GetTl2b()*vTurbulenceGrad;
vTurbPQR(eP) = vBodyTurbGrad(eY)/Aircraft->GetWingSpan();
- if (Aircraft->GetHTailArm() != 0.0)
+ if (Aircraft->GetHTailArm() > 0)
vTurbPQR(eQ) = vBodyTurbGrad(eZ)/Aircraft->GetHTailArm();
else
vTurbPQR(eQ) = vBodyTurbGrad(eZ)/10.0;
- if (Aircraft->GetVTailArm())
+ if (Aircraft->GetVTailArm() > 0)
vTurbPQR(eR) = vBodyTurbGrad(eX)/Aircraft->GetVTailArm();
else
vTurbPQR(eR) = vBodyTurbGrad(eX)/10.0;
break;
+ }
default:
break;
}
}
+//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+void FGAtmosphere::UseExternal(void) {
+ temperature=&exTemperature;
+ pressure=&exPressure;
+ density=&exDensity;
+ useExternal=true;
+}
+
+//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+void FGAtmosphere::UseInternal(void) {
+ temperature=&intTemperature;
+ pressure=&intPressure;
+ density=&intDensity;
+ useExternal=false;
+}
+
+//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+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/delta-T", this,
+ &FGAtmosphere::GetDeltaT, &FGAtmosphere::SetDeltaT);
+ PropertyManager->Tie("atmosphere/T-sl-dev-F", this,
+ &FGAtmosphere::GetSLTempDev, &FGAtmosphere::SetSLTempDev);
+ PropertyManager->Tie("atmosphere/density-altitude", this,
+ &FGAtmosphere::GetDensityAltitude);
+ 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/delta-T");
+ PropertyManager->Untie("atmosphere/T-sl-dev-F");
+ PropertyManager->Untie("atmosphere/density-altitude");
+ 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
}
}
-void FGAtmosphere::bind(void){
- 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,
- &FGAtmosphere::GetTurbPQR);
- PropertyManager->Tie("atmosphere/q-turb-rad_sec", this,2,
- &FGAtmosphere::GetTurbPQR);
- PropertyManager->Tie("atmosphere/r-turb-rad_sec", this,3,
- &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");
-}
+} // namespace JSBSim
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