//=========================================================================
// Update Temperature, pressure and density from altitude
// NOTE: Temperature is adjusted with the local conditions
// if local condition say 20°C, then temperature is adusted
// by the delta (20 - 15) because 15°C is the standard temperature
// at sea level; We just make a (certainly) wrong supposition by
// saying that temperature is 5° higgher at all altitude
//=========================================================================
void CAtmosphereModelJSBSim::TimeSlice(float dt,double altitude)
{ //---Compute temperature and pressure -----------------------
// slot.U = slope
// slot.V = Temperature in Rankine
// slot.W = pressure (psf)
C3valSlot *slot = stdATMOS.Getfloor(altitude);
float slp = slot->GetU();
float rfT = slot->GetV();
float rfP = slot->GetW();
float da = altitude - slot->GetX();
float tp = 0;
float pr = 0;
float dn = 0;
//---Compute new targets ---------------------
if (0 == slp)
{ tp = rfT;
pr = rfP * exp(-pInertial->SLgravity()/(rfT*Reng)* da);
dn = pr/ (Reng*tp);
}
else
{ tp = rfT + (slp * da);
pr = rfP * pow(float(tp/rfT),float(-pInertial->SLgravity()/(slp*Reng)));
dn = pr/(Reng*tp);
}
//--- Get final values -----------------------------------------------
tempR = tVAL.TimeSlice(dt);
presS = pVAL.TimeSlice(dt);
densD = dVAL.TimeSlice(dt);
//--- Set Target value -----------------------------------------------
tVAL.Set(tp);
pVAL.Set(pr);
dVAL.Set(dn);
//---Update temperature to various units -----------------------------
tempC = RankineToCelsius(tempR) + dtaTC;
tempF = CelsiusToFahrenheit(tempC);
//---Update pressure to various units --------------------------------
presS += dtaPS; // Add local deviation
presH = presS * PSF_TO_INHG;
presB = presS * PFS_TO_HPA;
//--- Update sound speed ---------------------------------------------
soundspeed = sqrt(SHRatio*Reng*(tempR));
//--------------------------------------------------------------------
// test others density
//densD *= 10.0;
//cout << "Atmosphere: h=" << altitude << " rho= " << densD << endl;
// #ifdef _DEBUG
// FILE *fp_debug;
// if(!(fp_debug = fopen("__DDEBUG_atmosphere.txt", "a")) == NULL)
// {
// int test = 0;
// fprintf(fp_debug, "TPD = %f %f %f\n", tempR, presS, densD);
// fprintf(fp_debug, "TPD = %f %f %f\n",
// RankineToCelsius (tempR),
// presS * PSF_TO_INHG,
// densD);
// fclose(fp_debug);
// }
// #endif
}
//=========================================================================
// Update Temperature, pressure and density from altitude
// NOTE: Temperature is adjusted with the local conditions
// if local condition say 20°C, then temperature is adusted
// by the delta (20 - 15) because 15°C is the standard temperature
// at sea level; We just make a (certainly) wrong supposition by
// saying that temperature is 5° higgher at all altitude
//=========================================================================
int CAtmosphereModelJSBSim::TimeSlice(float dt,U_INT frame)
{ double altitude = globals->geop.alt;
//---Compute temperature and pressure -----------------------
C3valSlot *slot = stdATMOS.Getfloor(altitude);
float slp = slot->GetU();
float rfT = slot->GetV();
float rfP = slot->GetW();
float da = altitude - slot->GetX();
float tp = 0;
float pr = 0;
float dn = 0;
//---Compute new targets ---------------------
if (0 == slp)
{ tp = rfT;
pr = rfP * exp(-pInertial->SLgravity()/(rfT*Reng)* da);
dn = pr/ (Reng*tp);
}
else
{ tp = rfT + (slp * da);
pr = rfP * pow(float(tp/rfT),float(-pInertial->SLgravity()/(slp*Reng)));
dn = pr/(Reng*tp);
}
//--- Get final values -----------------------------------------------
tempR = tVAL.TimeSlice(dt);
presS = pVAL.TimeSlice(dt);
densD = dVAL.TimeSlice(dt);
//--- Set Target value -----------------------------------------------
tVAL.Set(tp);
pVAL.Set(pr);
dVAL.Set(dn);
//---Update temperature to various units -----------------------------
tempC = RankineToCelsius(tempR) + dtaTC;
tempF = CelsiusToFahrenheit(tempC);
//---Update pressure to various units --------------------------------
presS += dtaPS; // Add local deviation
presH = presS * PSF_TO_INHG;
presB = presS * PFS_TO_HPA;
//--- Update sound speed ---------------------------------------------
soundspeed = sqrt(SHRatio*Reng*(tempR));
return 1;
}
