src/FDM/JSBSim/models/FGAtmosphere.cpp

   1 /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
   2
   3  Module:       FGAtmosphere.cpp
   4  Author:       Jon Berndt
   5                Implementation of 1959 Standard Atmosphere added by Tony Peden
   6  Date started: 11/24/98
   7  Purpose:      Models the atmosphere
   8  Called by:    FGSimExec
   9
  10  ------------- Copyright (C) 1999  Jon S. Berndt (jon@jsbsim.org) -------------
  11
  12  This program is free software; you can redistribute it and/or modify it under
  13  the terms of the GNU Lesser General Public License as published by the Free Software
  14  Foundation; either version 2 of the License, or (at your option) any later
  15  version.
  16
  17  This program is distributed in the hope that it will be useful, but WITHOUT
  18  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  19  FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more
  20  details.
  21
  22  You should have received a copy of the GNU Lesser General Public License along with
  23  this program; if not, write to the Free Software Foundation, Inc., 59 Temple
  24  Place - Suite 330, Boston, MA  02111-1307, USA.
  25
  26  Further information about the GNU Lesser General Public License can also be found on
  27  the world wide web at http://www.gnu.org.
  28
  29 FUNCTIONAL DESCRIPTION
  30 --------------------------------------------------------------------------------
  31 Models the atmosphere. The equation used below was determined by a third order
  32 curve fit using Excel. The data is from the ICAO atmosphere model.
  33
  34 HISTORY
  35 --------------------------------------------------------------------------------
  36 11/24/98   JSB   Created
  37 07/23/99   TP    Added implementation of 1959 Standard Atmosphere
  38                  Moved calculation of Mach number to FGPropagate
  39                  Later updated to '76 model
  40 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  41 COMMENTS, REFERENCES,  and NOTES
  42 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  43 [1]   Anderson, John D. "Introduction to Flight, Third Edition", McGraw-Hill,
  44       1989, ISBN 0-07-001641-0
  45
  46 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  47 INCLUDES
  48 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
  49
  50 #include "FGAtmosphere.h"
  51 #include "FGState.h"
  52 #include "FGFDMExec.h"
  53 #include "FGAircraft.h"
  54 #include "FGPropagate.h"
  55 #include "FGInertial.h"
  56 #include "input_output/FGPropertyManager.h"
  57 #include <iostream>
  58 #include <cstdlib>
  59
  60 using namespace std;
  61
  62 namespace JSBSim {
  63
  64 static const char *IdSrc = "$Id$";
  65 static const char *IdHdr = ID_ATMOSPHERE;
  66
  67 /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  68 CLASS IMPLEMENTATION
  69 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
  70
  71 FGAtmosphere::FGAtmosphere(FGFDMExec* fdmex) : FGModel(fdmex)
  72 {
  73   Name = "FGAtmosphere";
  74   lastIndex = 0;
  75   h = 0.0;
  76   psiw = 0.0;
  77   htab[0]=0;
  78   htab[1]= 36089.0;
  79   htab[2]= 65617.0;
  80   htab[3]=104987.0;
  81   htab[4]=154199.0;
  82   htab[5]=167322.0;
  83   htab[6]=232940.0;
  84   htab[7]=278385.0; //ft.
  85
  86   MagnitudedAccelDt = MagnitudeAccel = Magnitude = 0.0;
  87 //  SetTurbType( ttCulp );
  88   SetTurbType( ttNone );
  89   TurbGain = 1.0;
  90   TurbRate = 10.0;
  91   Rhythmicity = 0.1;
  92   spike = target_time = strength = 0.0;
  93   wind_from_clockwise = 0.0;
  94   SutherlandConstant = 198.72; // deg Rankine
  95   Beta = 2.269690E-08; // slug/(sec ft R^0.5)
  96
  97   T_dev_sl = T_dev = delta_T = 0.0;
  98   StandardTempOnly = false;
  99   first_pass = true;
 100   vGustNED.InitMatrix();
 101   vTurbulenceNED.InitMatrix();
 102
 103   bind();
 104   Debug(0);
 105 }
 106
 107 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 108
 109 FGAtmosphere::~FGAtmosphere()
 110 {
 111   Debug(1);
 112 }
 113
 114 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 115
 116 bool FGAtmosphere::InitModel(void)
 117 {
 118   if (!FGModel::InitModel()) return false;
 119
 120   UseInternal();  // this is the default
 121
 122   Calculate(h);
 123   StdSLtemperature = SLtemperature = 518.67;
 124   StdSLpressure    = SLpressure = 2116.22;
 125   StdSLdensity     = SLdensity = 0.00237767;
 126   StdSLsoundspeed  = SLsoundspeed = sqrt(SHRatio*Reng*StdSLtemperature);
 127   rSLtemperature = 1.0/StdSLtemperature;
 128   rSLpressure    = 1.0/StdSLpressure;
 129   rSLdensity     = 1.0/StdSLdensity;
 130   rSLsoundspeed  = 1.0/StdSLsoundspeed;
 131
 132   return true;
 133 }
 134
 135 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 136
 137 bool FGAtmosphere::Run(void)
 138 {
 139   if (FGModel::Run()) return true;
 140   if (FDMExec->Holding()) return false;
 141
 142   T_dev = 0.0;
 143   h = Propagate->GetAltitudeASL();
 144
 145   if (!useExternal) {
 146     Calculate(h);
 147     CalculateDerived();
 148   } else {
 149     CalculateDerived();
 150   }
 151
 152   Debug(2);
 153   return false;
 154 }
 155
 156 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 157 //
 158 // See reference 1
 159
 160 void FGAtmosphere::Calculate(double altitude)
 161 {
 162   double slope, reftemp, refpress;
 163   int i = lastIndex;
 164
 165   if (altitude < htab[lastIndex]) {
 166     if (altitude <= 0) {
 167       i = 0;
 168       altitude=0;
 169     } else {
 170        i = lastIndex-1;
 171        while (htab[i] > altitude) i--;
 172     }
 173   } else if (altitude > htab[lastIndex+1]) {
 174     if (altitude >= htab[7]) {
 175       i = 7;
 176       altitude = htab[7];
 177     } else {
 178       i = lastIndex+1;
 179       while (htab[i+1] < altitude) i++;
 180     }
 181   }
 182
 183   switch(i) {
 184   case 0: // Sea level
 185     slope     = -0.00356616; // R/ft.
 186     reftemp   = 518.67;   // in degrees Rankine, 288.15 Kelvin
 187     refpress  = 2116.22;    // psf
 188     //refdens   = 0.00237767;  // slugs/cubic ft.
 189     break;
 190   case 1:     // 36089 ft. or 11 km
 191     slope     = 0;
 192     reftemp   = 389.97; // in degrees Rankine, 216.65 Kelvin
 193     refpress  = 472.763;
 194     //refdens   = 0.000706032;
 195     break;
 196   case 2:     // 65616 ft. or 20 km
 197     slope     = 0.00054864;
 198     reftemp   = 389.97; // in degrees Rankine, 216.65 Kelvin
 199     refpress  = 114.636;
 200     //refdens   = 0.000171306;
 201     break;
 202   case 3:     // 104986 ft. or 32 km
 203     slope     = 0.001536192;
 204     reftemp   = 411.57; // in degrees Rankine, 228.65 Kelvin
 205     refpress  = 18.128;
 206     //refdens   = 1.18422e-05;
 207     break;
 208   case 4:     // 154199 ft. 47 km
 209     slope     = 0;
 210     reftemp   = 487.17; // in degrees Rankine, 270.65 Kelvin
 211     refpress  = 2.316;
 212     //refdens   = 4.00585e-7;
 213     break;
 214   case 5:     // 167322 ft. or 51 km
 215     slope     = -0.001536192;
 216     reftemp   = 487.17; // in degrees Rankine, 270.65 Kelvin
 217     refpress  = 1.398;
 218     //refdens   = 8.17102e-7;
 219     break;
 220   case 6:     // 232940 ft. or 71 km
 221     slope     = -0.00109728;
 222     reftemp   = 386.368; // in degrees Rankine, 214.649 Kelvin
 223     refpress  = 0.0826;
 224     //refdens   = 8.77702e-9;
 225     break;
 226   case 7:     // 278385 ft. or 84.8520 km
 227     slope     = 0;
 228     reftemp   = 336.5; // in degrees Rankine, 186.94 Kelvin
 229     refpress  = 0.00831;
 230     //refdens   = 2.19541e-10;
 231     break;
 232   default:     // sea level
 233     slope     = -0.00356616; // R/ft.
 234     reftemp   = 518.67;   // in degrees Rankine, 288.15 Kelvin
 235     refpress  = 2116.22;    // psf
 236     //refdens   = 0.00237767;  // slugs/cubic ft.
 237     break;
 238
 239   }
 240
 241   // If delta_T is set, then that is our temperature deviation at any altitude.
 242   // If not, then we'll estimate a deviation based on the sea level deviation (if set).
 243
 244   if(!StandardTempOnly) {
 245     T_dev = 0.0;
 246     if (delta_T != 0.0) {
 247       T_dev = delta_T;
 248     } else {
 249       if ((altitude < 36089.239) && (T_dev_sl != 0.0)) {
 250         T_dev = T_dev_sl * ( 1.0 - (altitude/36089.239));
 251       }
 252     }
 253     reftemp+=T_dev;
 254   }
 255
 256   if (slope == 0) {
 257     intTemperature = reftemp;
 258     intPressure = refpress*exp(-Inertial->SLgravity()/(reftemp*Reng)*(altitude-htab[i]));
 259     intDensity = intPressure/(Reng*intTemperature);
 260   } else {
 261     intTemperature = reftemp+slope*(altitude-htab[i]);
 262     intPressure = refpress*pow(intTemperature/reftemp,-Inertial->SLgravity()/(slope*Reng));
 263     intDensity = intPressure/(Reng*intTemperature);
 264   }
 265
 266   lastIndex=i;
 267 }
 268
 269 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 270 // Calculate parameters derived from T, P and rho
 271 // Sum gust and turbulence values in NED frame into the wind vector.
 272
 273 void FGAtmosphere::CalculateDerived(void)
 274 {
 275   T_dev = (*temperature) - GetTemperature(h);
 276   density_altitude = h + T_dev * 66.7;
 277
 278   if (turbType != ttNone) Turbulence();
 279
 280   vTotalWindNED = vWindNED + vGustNED + vTurbulenceNED;
 281
 282    // psiw (Wind heading) is the direction the wind is blowing towards
 283   if (vWindNED(eX) != 0.0) psiw = atan2( vWindNED(eY), vWindNED(eX) );
 284   if (psiw < 0) psiw += 2*M_PI;
 285
 286   soundspeed = sqrt(SHRatio*Reng*(*temperature));
 287
 288   intViscosity = Beta * pow(intTemperature, 1.5) / (SutherlandConstant + intTemperature);
 289   intKinematicViscosity = intViscosity / intDensity;
 290 }
 291
 292
 293 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 294 // Get the standard atmospheric properties at a specified altitude
 295
 296 void FGAtmosphere::GetStdAtmosphere(double altitude) {
 297   StandardTempOnly = true;
 298   Calculate(altitude);
 299   StandardTempOnly = false;
 300   atmosphere.Temperature = intTemperature;
 301   atmosphere.Pressure = intPressure;
 302   atmosphere.Density = intDensity;
 303
 304   // Reset the internal atmospheric state
 305   Calculate(h);
 306 }
 307
 308 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 309 // Get the standard pressure at a specified altitude
 310
 311 double FGAtmosphere::GetPressure(double altitude) {
 312   GetStdAtmosphere(altitude);
 313   return atmosphere.Pressure;
 314 }
 315
 316 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 317 // Get the standard temperature at a specified altitude
 318
 319 double FGAtmosphere::GetTemperature(double altitude) {
 320   GetStdAtmosphere(altitude);
 321   return atmosphere.Temperature;
 322 }
 323
 324 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 325 // Get the standard density at a specified altitude
 326
 327 double FGAtmosphere::GetDensity(double altitude) {
 328   GetStdAtmosphere(altitude);
 329   return atmosphere.Density;
 330 }
 331
 332
 333 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 334 // square a value, but preserve the original sign
 335
 336 static inline double square_signed (double value)
 337 {
 338     if (value < 0)
 339         return value * value * -1;
 340     else
 341         return value * value;
 342 }
 343
 344 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 345 //
 346 // psi is the angle that the wind is blowing *towards*
 347
 348 void FGAtmosphere::SetWindspeed(double speed)
 349 {
 350   if (vWindNED.Magnitude() == 0.0) {
 351     psiw = 0.0;
 352     vWindNED(eNorth) = speed;
 353   } else {
 354     vWindNED(eNorth) = speed * cos(psiw);
 355     vWindNED(eEast) = speed * sin(psiw);
 356     vWindNED(eDown) = 0.0;
 357   }
 358 }
 359
 360 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 361
 362 double FGAtmosphere::GetWindspeed(void) const
 363 {
 364   return vWindNED.Magnitude();
 365 }
 366
 367 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 368 //
 369 // psi is the angle that the wind is blowing *towards*
 370
 371 void FGAtmosphere::SetWindPsi(double dir)
 372 {
 373   double mag = GetWindspeed();
 374   psiw = dir;
 375   SetWindspeed(mag);
 376 }
 377
 378 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 379
 380 void FGAtmosphere::Turbulence(void)
 381 {
 382   double DeltaT = rate*State->Getdt();
 383
 384   switch (turbType) {
 385   case ttStandard: {
 386     // TurbGain = TurbGain * TurbGain * 100.0; // what is this!?
 387
 388     vDirectiondAccelDt(eX) = 1 - 2.0*(double(rand())/double(RAND_MAX));
 389     vDirectiondAccelDt(eY) = 1 - 2.0*(double(rand())/double(RAND_MAX));
 390     vDirectiondAccelDt(eZ) = 1 - 2.0*(double(rand())/double(RAND_MAX));
 391
 392     MagnitudedAccelDt = 1 - 2.0*(double(rand())/double(RAND_MAX)) - Magnitude;
 393                                 // Scale the magnitude so that it moves
 394                                 // away from the peaks
 395     MagnitudedAccelDt = ((MagnitudedAccelDt - Magnitude) /
 396                          (1 + fabs(Magnitude)));
 397     MagnitudeAccel    += MagnitudedAccelDt*TurbRate*DeltaT;
 398     Magnitude         += MagnitudeAccel*DeltaT;
 399     Magnitude          = fabs(Magnitude);
 400
 401     vDirectiondAccelDt.Normalize();
 402
 403                                 // deemphasise non-vertical forces
 404     vDirectiondAccelDt(eX) = square_signed(vDirectiondAccelDt(eX));
 405     vDirectiondAccelDt(eY) = square_signed(vDirectiondAccelDt(eY));
 406
 407     vDirectionAccel += vDirectiondAccelDt*TurbRate*DeltaT;
 408     vDirectionAccel.Normalize();
 409     vDirection      += vDirectionAccel*DeltaT;
 410
 411     vDirection.Normalize();
 412
 413                                 // Diminish turbulence within three wingspans
 414                                 // of the ground
 415     vTurbulenceNED = TurbGain * Magnitude * vDirection;
 416     double HOverBMAC = Auxiliary->GetHOverBMAC();
 417     if (HOverBMAC < 3.0)
 418         vTurbulenceNED *= (HOverBMAC / 3.0) * (HOverBMAC / 3.0);
 419
 420     // I don't believe these next two statements calculate the proper gradient over
 421     // the aircraft body. One reason is because this has no relationship with the
 422     // orientation or velocity of the aircraft, which it must have. What is vTurbulenceGrad
 423     // supposed to represent? And the direction and magnitude of the turbulence can change,
 424     // so both accelerations need to be accounted for, no?
 425
 426     // Need to determine the turbulence change in body axes between two time points.
 427
 428     vTurbulenceGrad = TurbGain*MagnitudeAccel * vDirection;
 429     vBodyTurbGrad = Propagate->GetTl2b()*vTurbulenceGrad;
 430
 431     if (Aircraft->GetWingSpan() > 0) {
 432       vTurbPQR(eP) = vBodyTurbGrad(eY)/Aircraft->GetWingSpan();
 433     } else {
 434       vTurbPQR(eP) = vBodyTurbGrad(eY)/30.0;
 435     }
 436 //     if (Aircraft->GetHTailArm() != 0.0)
 437 //       vTurbPQR(eQ) = vBodyTurbGrad(eZ)/Aircraft->GetHTailArm();
 438 //     else
 439 //       vTurbPQR(eQ) = vBodyTurbGrad(eZ)/10.0;
 440
 441     if (Aircraft->GetVTailArm() > 0)
 442       vTurbPQR(eR) = vBodyTurbGrad(eX)/Aircraft->GetVTailArm();
 443     else
 444       vTurbPQR(eR) = vBodyTurbGrad(eX)/10.0;
 445
 446                                 // Clear the horizontal forces
 447                                 // actually felt by the plane, now
 448                                 // that we've used them to calculate
 449                                 // moments.
 450                                 // Why? (JSB)
 451 //    vTurbulenceNED(eX) = 0.0;
 452 //    vTurbulenceNED(eY) = 0.0;
 453
 454     break;
 455   }
 456   case ttBerndt: { // This is very experimental and incomplete at the moment.
 457
 458     vDirectiondAccelDt(eX) = GaussianRandomNumber();
 459     vDirectiondAccelDt(eY) = GaussianRandomNumber();
 460     vDirectiondAccelDt(eZ) = GaussianRandomNumber();
 461 /*
 462     MagnitudedAccelDt = GaussianRandomNumber();
 463     MagnitudeAccel    += MagnitudedAccelDt * DeltaT;
 464     Magnitude         += MagnitudeAccel * DeltaT;
 465 */
 466     Magnitude         += GaussianRandomNumber() * DeltaT;
 467
 468     vDirectiondAccelDt.Normalize();
 469     vDirectionAccel += TurbRate * vDirectiondAccelDt * DeltaT;
 470     vDirectionAccel.Normalize();
 471     vDirection      += vDirectionAccel*DeltaT;
 472
 473     // Diminish z-vector within two wingspans of the ground
 474     double HOverBMAC = Auxiliary->GetHOverBMAC();
 475     if (HOverBMAC < 2.0) vDirection(eZ) *= HOverBMAC / 2.0;
 476
 477     vDirection.Normalize();
 478
 479     vTurbulenceNED = TurbGain*Magnitude * vDirection;
 480     vTurbulenceGrad = TurbGain*MagnitudeAccel * vDirection;
 481
 482     vBodyTurbGrad = Propagate->GetTl2b() * vTurbulenceGrad;
 483     vTurbPQR(eP) = vBodyTurbGrad(eY) / Aircraft->GetWingSpan();
 484     if (Aircraft->GetHTailArm() > 0)
 485       vTurbPQR(eQ) = vBodyTurbGrad(eZ) / Aircraft->GetHTailArm();
 486     else
 487       vTurbPQR(eQ) = vBodyTurbGrad(eZ) / 10.0;
 488
 489     if (Aircraft->GetVTailArm() > 0)
 490       vTurbPQR(eR) = vBodyTurbGrad(eX) / Aircraft->GetVTailArm();
 491     else
 492       vTurbPQR(eR) = vBodyTurbGrad(eX)/10.0;
 493
 494     break;
 495   }
 496   case ttCulp: {
 497
 498     vTurbPQR(eP) = wind_from_clockwise;
 499     if (TurbGain == 0.0) return;
 500
 501     // keep the inputs within allowable limts for this model
 502     if (TurbGain < 0.0) TurbGain = 0.0;
 503     if (TurbGain > 1.0) TurbGain = 1.0;
 504     if (TurbRate < 0.0) TurbRate = 0.0;
 505     if (TurbRate > 30.0) TurbRate = 30.0;
 506     if (Rhythmicity < 0.0) Rhythmicity = 0.0;
 507     if (Rhythmicity > 1.0) Rhythmicity = 1.0;
 508
 509     // generate a sine wave corresponding to turbulence rate in hertz
 510     double time = FDMExec->GetSimTime();
 511     double sinewave = sin( time * TurbRate * 6.283185307 );
 512
 513     double random = 0.0;
 514     if (target_time == 0.0) {
 515       strength = random = 1 - 2.0*(double(rand())/double(RAND_MAX));
 516       target_time = time + 0.71 + (random * 0.5);
 517     }
 518     if (time > target_time) {
 519       spike = 1.0;
 520       target_time = 0.0;
 521     }
 522
 523     // max vertical wind speed in fps, corresponds to TurbGain = 1.0
 524     double max_vs = 40;
 525
 526     vTurbulenceNED(1) = vTurbulenceNED(2) = vTurbulenceNED(3) = 0.0;
 527     double delta = strength * max_vs * TurbGain * (1-Rhythmicity) * spike;
 528
 529     // Vertical component of turbulence.
 530     vTurbulenceNED(3) = sinewave * max_vs * TurbGain * Rhythmicity;
 531     vTurbulenceNED(3)+= delta;
 532     double HOverBMAC = Auxiliary->GetHOverBMAC();
 533     if (HOverBMAC < 3.0)
 534         vTurbulenceNED(3) *= HOverBMAC * 0.3333;
 535
 536     // Yaw component of turbulence.
 537     vTurbulenceNED(1) = sin( delta * 3.0 );
 538     vTurbulenceNED(2) = cos( delta * 3.0 );
 539
 540     // Roll component of turbulence. Clockwise vortex causes left roll.
 541     vTurbPQR(eP) += delta * 0.04;
 542
 543     spike = spike * 0.9;
 544     break;
 545   }
 546   default:
 547     break;
 548   }
 549 }
 550
 551 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 552
 553 void FGAtmosphere::UseExternal(void)
 554 {
 555   temperature=&exTemperature;
 556   pressure=&exPressure;
 557   density=&exDensity;
 558   useExternal=true;
 559 }
 560
 561 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 562
 563 void FGAtmosphere::UseInternal(void)
 564 {
 565   temperature=&intTemperature;
 566   pressure=&intPressure;
 567   density=&intDensity;
 568   useExternal=false;
 569 }
 570
 571 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 572
 573 void FGAtmosphere::bind(void)
 574 {
 575   typedef double (FGAtmosphere::*PMF)(int) const;
 576   typedef double (FGAtmosphere::*PMFv)(void) const;
 577   typedef int (FGAtmosphere::*PMFt)(void) const;
 578   typedef void   (FGAtmosphere::*PMFd)(int,double);
 579   typedef void   (FGAtmosphere::*PMFi)(int);
 580   PropertyManager->Tie("atmosphere/T-R", this, (PMFv)&FGAtmosphere::GetTemperature);
 581   PropertyManager->Tie("atmosphere/rho-slugs_ft3", this, (PMFv)&FGAtmosphere::GetDensity);
 582   PropertyManager->Tie("atmosphere/P-psf", this, (PMFv)&FGAtmosphere::GetPressure);
 583   PropertyManager->Tie("atmosphere/a-fps", this, &FGAtmosphere::GetSoundSpeed);
 584   PropertyManager->Tie("atmosphere/T-sl-R", this, &FGAtmosphere::GetTemperatureSL);
 585   PropertyManager->Tie("atmosphere/rho-sl-slugs_ft3", this, &FGAtmosphere::GetDensitySL);
 586   PropertyManager->Tie("atmosphere/P-sl-psf", this, &FGAtmosphere::GetPressureSL);
 587   PropertyManager->Tie("atmosphere/a-sl-fps", this, &FGAtmosphere::GetSoundSpeedSL);
 588   PropertyManager->Tie("atmosphere/theta", this, &FGAtmosphere::GetTemperatureRatio);
 589   PropertyManager->Tie("atmosphere/sigma", this, &FGAtmosphere::GetDensityRatio);
 590   PropertyManager->Tie("atmosphere/delta", this, &FGAtmosphere::GetPressureRatio);
 591   PropertyManager->Tie("atmosphere/a-ratio", this, &FGAtmosphere::GetSoundSpeedRatio);
 592   PropertyManager->Tie("atmosphere/psiw-rad", this, &FGAtmosphere::GetWindPsi, &FGAtmosphere::SetWindPsi);
 593   PropertyManager->Tie("atmosphere/delta-T", this, &FGAtmosphere::GetDeltaT, &FGAtmosphere::SetDeltaT);
 594   PropertyManager->Tie("atmosphere/T-sl-dev-F", this, &FGAtmosphere::GetSLTempDev, &FGAtmosphere::SetSLTempDev);
 595   PropertyManager->Tie("atmosphere/density-altitude", this, &FGAtmosphere::GetDensityAltitude);
 596
 597   PropertyManager->Tie("atmosphere/wind-north-fps", this, eNorth, (PMF)&FGAtmosphere::GetWindNED,
 598                                                           (PMFd)&FGAtmosphere::SetWindNED);
 599   PropertyManager->Tie("atmosphere/wind-east-fps",  this, eEast, (PMF)&FGAtmosphere::GetWindNED,
 600                                                           (PMFd)&FGAtmosphere::SetWindNED);
 601   PropertyManager->Tie("atmosphere/wind-down-fps",  this, eDown, (PMF)&FGAtmosphere::GetWindNED,
 602                                                           (PMFd)&FGAtmosphere::SetWindNED);
 603   PropertyManager->Tie("atmosphere/wind-mag-fps", this, &FGAtmosphere::GetWindspeed,
 604                                                         &FGAtmosphere::SetWindspeed);
 605   PropertyManager->Tie("atmosphere/total-wind-north-fps", this, eNorth, (PMF)&FGAtmosphere::GetTotalWindNED);
 606   PropertyManager->Tie("atmosphere/total-wind-east-fps",  this, eEast,  (PMF)&FGAtmosphere::GetTotalWindNED);
 607   PropertyManager->Tie("atmosphere/total-wind-down-fps",  this, eDown,  (PMF)&FGAtmosphere::GetTotalWindNED);
 608
 609   PropertyManager->Tie("atmosphere/gust-north-fps", this, eNorth, (PMF)&FGAtmosphere::GetGustNED,
 610                                                           (PMFd)&FGAtmosphere::SetGustNED);
 611   PropertyManager->Tie("atmosphere/gust-east-fps",  this, eEast, (PMF)&FGAtmosphere::GetGustNED,
 612                                                           (PMFd)&FGAtmosphere::SetGustNED);
 613   PropertyManager->Tie("atmosphere/gust-down-fps",  this, eDown, (PMF)&FGAtmosphere::GetGustNED,
 614                                                           (PMFd)&FGAtmosphere::SetGustNED);
 615
 616   PropertyManager->Tie("atmosphere/turb-north-fps", this, eNorth, (PMF)&FGAtmosphere::GetTurbNED,
 617                                                           (PMFd)&FGAtmosphere::SetTurbNED);
 618   PropertyManager->Tie("atmosphere/turb-east-fps",  this, eEast, (PMF)&FGAtmosphere::GetTurbNED,
 619                                                           (PMFd)&FGAtmosphere::SetTurbNED);
 620   PropertyManager->Tie("atmosphere/turb-down-fps",  this, eDown, (PMF)&FGAtmosphere::GetTurbNED,
 621                                                           (PMFd)&FGAtmosphere::SetTurbNED);
 622
 623   PropertyManager->Tie("atmosphere/p-turb-rad_sec", this,1, (PMF)&FGAtmosphere::GetTurbPQR);
 624   PropertyManager->Tie("atmosphere/q-turb-rad_sec", this,2, (PMF)&FGAtmosphere::GetTurbPQR);
 625   PropertyManager->Tie("atmosphere/r-turb-rad_sec", this,3, (PMF)&FGAtmosphere::GetTurbPQR);
 626   PropertyManager->Tie("atmosphere/turb-type", this, (PMFt)&FGAtmosphere::GetTurbType, (PMFi)&FGAtmosphere::SetTurbType);
 627   PropertyManager->Tie("atmosphere/turb-rate", this, &FGAtmosphere::GetTurbRate, &FGAtmosphere::SetTurbRate);
 628   PropertyManager->Tie("atmosphere/turb-gain", this, &FGAtmosphere::GetTurbGain, &FGAtmosphere::SetTurbGain);
 629   PropertyManager->Tie("atmosphere/turb-rhythmicity", this, &FGAtmosphere::GetRhythmicity,
 630                                                             &FGAtmosphere::SetRhythmicity);
 631 }
 632
 633 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 634 //    The bitmasked value choices are as follows:
 635 //    unset: In this case (the default) JSBSim would only print
 636 //       out the normally expected messages, essentially echoing
 637 //       the config files as they are read. If the environment
 638 //       variable is not set, debug_lvl is set to 1 internally
 639 //    0: This requests JSBSim not to output any messages
 640 //       whatsoever.
 641 //    1: This value explicity requests the normal JSBSim
 642 //       startup messages
 643 //    2: This value asks for a message to be printed out when
 644 //       a class is instantiated
 645 //    4: When this value is set, a message is displayed when a
 646 //       FGModel object executes its Run() method
 647 //    8: When this value is set, various runtime state variables
 648 //       are printed out periodically
 649 //    16: When set various parameters are sanity checked and
 650 //       a message is printed out when they go out of bounds
 651
 652 void FGAtmosphere::Debug(int from)
 653 {
 654   if (debug_lvl <= 0) return;
 655
 656   if (debug_lvl & 1) { // Standard console startup message output
 657     if (from == 0) { // Constructor
 658     }
 659   }
 660   if (debug_lvl & 2 ) { // Instantiation/Destruction notification
 661     if (from == 0) cout << "Instantiated: FGAtmosphere" << endl;
 662     if (from == 1) cout << "Destroyed:    FGAtmosphere" << endl;
 663   }
 664   if (debug_lvl & 4 ) { // Run() method entry print for FGModel-derived objects
 665   }
 666   if (debug_lvl & 8 ) { // Runtime state variables
 667   }
 668   if (debug_lvl & 16) { // Sanity checking
 669   }
 670   if (debug_lvl & 128) { // Turbulence
 671     if (first_pass && from == 2) {
 672       first_pass = false;
 673       cout << "vTurbulenceNED(X), vTurbulenceNED(Y), vTurbulenceNED(Z), "
 674            << "vTurbulenceGrad(X), vTurbulenceGrad(Y), vTurbulenceGrad(Z), "
 675            << "vDirection(X), vDirection(Y), vDirection(Z), "
 676            << "Magnitude, "
 677            << "vTurbPQR(P), vTurbPQR(Q), vTurbPQR(R), " << endl;
 678     }
 679     if (from == 2) {
 680       cout << vTurbulenceNED << ", " << vTurbulenceGrad << ", " << vDirection << ", " << Magnitude << ", " << vTurbPQR << endl;
 681     }
 682   }
 683   if (debug_lvl & 64) {
 684     if (from == 0) { // Constructor
 685       cout << IdSrc << endl;
 686       cout << IdHdr << endl;
 687     }
 688   }
 689 }
 690
 691 } // namespace JSBSim