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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 "FGAircraft.h"
52 : : #include "FGPropagate.h"
53 : : #include "FGInertial.h"
54 : : #include "FGAuxiliary.h"
55 : : #include "FGFDMExec.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: FGAtmosphere.cpp,v 1.37 2010/08/22 03:53:10 jberndt Exp $";
65 : : static const char *IdHdr = ID_ATMOSPHERE;
66 : :
67 : : /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
68 : : CLASS IMPLEMENTATION
69 : : %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
70 : :
71 : 1 : FGAtmosphere::FGAtmosphere(FGFDMExec* fdmex) : FGModel(fdmex)
72 : : {
73 : 1 : Name = "FGAtmosphere";
74 : 1 : lastIndex = 0;
75 : 1 : h = 0.0;
76 : 1 : psiw = 0.0;
77 : 1 : htab[0]=0;
78 : 1 : htab[1]= 36089.0;
79 : 1 : htab[2]= 65617.0;
80 : 1 : htab[3]=104987.0;
81 : 1 : htab[4]=154199.0;
82 : 1 : htab[5]=167322.0;
83 : 1 : htab[6]=232940.0;
84 : 1 : htab[7]=278385.0; //ft.
85 : :
86 : 1 : MagnitudedAccelDt = MagnitudeAccel = Magnitude = 0.0;
87 : : // SetTurbType( ttCulp );
88 : : SetTurbType( ttNone );
89 : 1 : TurbGain = 1.0;
90 : 1 : TurbRate = 10.0;
91 : 1 : Rhythmicity = 0.1;
92 : 1 : spike = target_time = strength = 0.0;
93 : 1 : wind_from_clockwise = 0.0;
94 : 1 : SutherlandConstant = 198.72; // deg Rankine
95 : 1 : Beta = 2.269690E-08; // slug/(sec ft R^0.5)
96 : :
97 : 1 : T_dev_sl = T_dev = delta_T = 0.0;
98 : 1 : StandardTempOnly = false;
99 : 1 : first_pass = true;
100 : 1 : vGustNED.InitMatrix();
101 : 1 : vTurbulenceNED.InitMatrix();
102 : :
103 : 1 : bind();
104 : 1 : Debug(0);
105 : 1 : }
106 : :
107 : : //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
108 : :
109 : 1 : FGAtmosphere::~FGAtmosphere()
110 : : {
111 : 1 : Debug(1);
112 : 1 : }
113 : :
114 : : //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
115 : :
116 : 1 : bool FGAtmosphere::InitModel(void)
117 : : {
118 [ - + ]: 1 : if (!FGModel::InitModel()) return false;
119 : :
120 : : UseInternal(); // this is the default
121 : :
122 : 1 : Calculate(h);
123 : 1 : StdSLtemperature = SLtemperature = 518.67;
124 : 1 : StdSLpressure = SLpressure = 2116.22;
125 : 1 : StdSLdensity = SLdensity = 0.00237767;
126 : 1 : StdSLsoundspeed = SLsoundspeed = sqrt(SHRatio*Reng*StdSLtemperature);
127 : 1 : rSLtemperature = 1.0/StdSLtemperature;
128 : 1 : rSLpressure = 1.0/StdSLpressure;
129 : 1 : rSLdensity = 1.0/StdSLdensity;
130 : 1 : rSLsoundspeed = 1.0/StdSLsoundspeed;
131 : :
132 : 1 : return true;
133 : : }
134 : :
135 : : //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
136 : :
137 : 54008 : bool FGAtmosphere::Run(void)
138 : : {
139 [ - + ]: 54008 : if (FGModel::Run()) return true;
140 [ - + ]: 54008 : if (FDMExec->Holding()) return false;
141 : :
142 : 54008 : RunPreFunctions();
143 : :
144 : 54008 : T_dev = 0.0;
145 : 108016 : h = Propagate->GetAltitudeASL();
146 : :
147 [ + - ]: 54008 : if (!useExternal) {
148 : 54008 : Calculate(h);
149 : 54008 : CalculateDerived();
150 : : } else {
151 : 0 : CalculateDerived();
152 : : }
153 : :
154 : 54008 : RunPostFunctions();
155 : :
156 : 54008 : Debug(2);
157 : 54008 : return false;
158 : : }
159 : :
160 : : //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
161 : : //
162 : : // See reference 1
163 : :
164 : 162025 : void FGAtmosphere::Calculate(double altitude)
165 : : {
166 : : double slope, reftemp, refpress;
167 : 162025 : int i = lastIndex;
168 : :
169 [ - + ]: 162025 : if (altitude < htab[lastIndex]) {
170 [ # # ]: 0 : if (altitude <= 0) {
171 : 0 : i = 0;
172 : 0 : altitude=0;
173 : : } else {
174 : 0 : i = lastIndex-1;
175 [ # # ]: 0 : while (htab[i] > altitude) i--;
176 : : }
177 [ + + ]: 162025 : } else if (altitude > htab[lastIndex+1]) {
178 [ + + ]: 107565 : if (altitude >= htab[7]) {
179 : 107559 : i = 7;
180 : 107559 : altitude = htab[7];
181 : : } else {
182 : 6 : i = lastIndex+1;
183 [ - + ]: 6 : while (htab[i+1] < altitude) i++;
184 : : }
185 : : }
186 : :
187 [ + + + + : 162025 : switch(i) {
+ + + +
- ]
188 : : case 0: // Sea level
189 : 24106 : slope = -0.00356616; // R/ft.
190 : 24106 : reftemp = 518.67; // in degrees Rankine, 288.15 Kelvin
191 : 24106 : refpress = 2116.22; // psf
192 : : //refdens = 0.00237767; // slugs/cubic ft.
193 : 24106 : break;
194 : : case 1: // 36089 ft. or 11 km
195 : 6366 : slope = 0;
196 : 6366 : reftemp = 389.97; // in degrees Rankine, 216.65 Kelvin
197 : 6366 : refpress = 472.763;
198 : : //refdens = 0.000706032;
199 : 6366 : break;
200 : : case 2: // 65616 ft. or 20 km
201 : 5994 : slope = 0.00054864;
202 : 5994 : reftemp = 389.97; // in degrees Rankine, 216.65 Kelvin
203 : 5994 : refpress = 114.636;
204 : : //refdens = 0.000171306;
205 : 5994 : break;
206 : : case 3: // 104986 ft. or 32 km
207 : 5784 : slope = 0.001536192;
208 : 5784 : reftemp = 411.57; // in degrees Rankine, 228.65 Kelvin
209 : 5784 : refpress = 18.128;
210 : : //refdens = 1.18422e-05;
211 : 5784 : break;
212 : : case 4: // 154199 ft. 47 km
213 : 1365 : slope = 0;
214 : 1365 : reftemp = 487.17; // in degrees Rankine, 270.65 Kelvin
215 : 1365 : refpress = 2.316;
216 : : //refdens = 4.00585e-7;
217 : 1365 : break;
218 : : case 5: // 167322 ft. or 51 km
219 : 6435 : slope = -0.001536192;
220 : 6435 : reftemp = 487.17; // in degrees Rankine, 270.65 Kelvin
221 : 6435 : refpress = 1.398;
222 : : //refdens = 8.17102e-7;
223 : 6435 : break;
224 : : case 6: // 232940 ft. or 71 km
225 : 4416 : slope = -0.00109728;
226 : 4416 : reftemp = 386.368; // in degrees Rankine, 214.649 Kelvin
227 : 4416 : refpress = 0.0826;
228 : : //refdens = 8.77702e-9;
229 : 4416 : break;
230 : : case 7: // 278385 ft. or 84.8520 km
231 : 107559 : slope = 0;
232 : 107559 : reftemp = 336.5; // in degrees Rankine, 186.94 Kelvin
233 : 107559 : refpress = 0.00831;
234 : : //refdens = 2.19541e-10;
235 : 107559 : break;
236 : : default: // sea level
237 : 0 : slope = -0.00356616; // R/ft.
238 : 0 : reftemp = 518.67; // in degrees Rankine, 288.15 Kelvin
239 : 0 : refpress = 2116.22; // psf
240 : : //refdens = 0.00237767; // slugs/cubic ft.
241 : : break;
242 : :
243 : : }
244 : :
245 : : // If delta_T is set, then that is our temperature deviation at any altitude.
246 : : // If not, then we'll estimate a deviation based on the sea level deviation (if set).
247 : :
248 [ + + ]: 162025 : if(!StandardTempOnly) {
249 : 108017 : T_dev = 0.0;
250 [ - + ]: 108017 : if (delta_T != 0.0) {
251 : 0 : T_dev = delta_T;
252 : : } else {
253 [ + + ][ - + ]: 108017 : if ((altitude < 36089.239) && (T_dev_sl != 0.0)) {
254 : 0 : T_dev = T_dev_sl * ( 1.0 - (altitude/36089.239));
255 : : }
256 : : }
257 : 108017 : reftemp+=T_dev;
258 : : }
259 : :
260 [ + + ]: 162025 : if (slope == 0) {
261 : 115290 : intTemperature = reftemp;
262 : 115290 : intPressure = refpress*exp(-Inertial->SLgravity()/(reftemp*Reng)*(altitude-htab[i]));
263 : 115290 : intDensity = intPressure/(Reng*intTemperature);
264 : : } else {
265 : 46735 : intTemperature = reftemp+slope*(altitude-htab[i]);
266 : 46735 : intPressure = refpress*pow(intTemperature/reftemp,-Inertial->SLgravity()/(slope*Reng));
267 : 46735 : intDensity = intPressure/(Reng*intTemperature);
268 : : }
269 : :
270 : 162025 : lastIndex=i;
271 : 162025 : }
272 : :
273 : : //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
274 : : // Calculate parameters derived from T, P and rho
275 : : // Sum gust and turbulence values in NED frame into the wind vector.
276 : :
277 : 54008 : void FGAtmosphere::CalculateDerived(void)
278 : : {
279 : 108016 : T_dev = (*temperature) - GetTemperature(h);
280 : :
281 [ + - ]: 54008 : if (T_dev == 0.0) density_altitude = h;
282 : 0 : else density_altitude = 518.67/0.00356616 * (1.0 - pow(GetDensityRatio(),0.235));
283 : :
284 [ - + ]: 54008 : if (turbType != ttNone) Turbulence();
285 : :
286 : 108016 : vTotalWindNED = vWindNED + vGustNED + vTurbulenceNED;
287 : :
288 : : // psiw (Wind heading) is the direction the wind is blowing towards
289 [ - + ]: 54008 : if (vWindNED(eX) != 0.0) psiw = atan2( vWindNED(eY), vWindNED(eX) );
290 [ - + ]: 54008 : if (psiw < 0) psiw += 2*M_PI;
291 : :
292 : 54008 : soundspeed = sqrt(SHRatio*Reng*(*temperature));
293 : :
294 : 54008 : intViscosity = Beta * pow(intTemperature, 1.5) / (SutherlandConstant + intTemperature);
295 : 54008 : intKinematicViscosity = intViscosity / intDensity;
296 : 54008 : }
297 : :
298 : :
299 : : //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
300 : : // Get the standard atmospheric properties at a specified altitude
301 : :
302 : 54008 : void FGAtmosphere::GetStdAtmosphere(double altitude) {
303 : 54008 : StandardTempOnly = true;
304 : 54008 : Calculate(altitude);
305 : 54008 : StandardTempOnly = false;
306 : 54008 : atmosphere.Temperature = intTemperature;
307 : 54008 : atmosphere.Pressure = intPressure;
308 : 54008 : atmosphere.Density = intDensity;
309 : :
310 : : // Reset the internal atmospheric state
311 : 54008 : Calculate(h);
312 : 54008 : }
313 : :
314 : : //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
315 : : // Get the standard pressure at a specified altitude
316 : :
317 : 0 : double FGAtmosphere::GetPressure(double altitude) {
318 : 0 : GetStdAtmosphere(altitude);
319 : 0 : return atmosphere.Pressure;
320 : : }
321 : :
322 : : //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
323 : : // Get the standard temperature at a specified altitude
324 : :
325 : 0 : double FGAtmosphere::GetTemperature(double altitude) {
326 : 54008 : GetStdAtmosphere(altitude);
327 : 0 : return atmosphere.Temperature;
328 : : }
329 : :
330 : : //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
331 : : // Get the standard density at a specified altitude
332 : :
333 : 0 : double FGAtmosphere::GetDensity(double altitude) {
334 : 0 : GetStdAtmosphere(altitude);
335 : 0 : return atmosphere.Density;
336 : : }
337 : :
338 : :
339 : : //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
340 : : // square a value, but preserve the original sign
341 : :
342 : : static inline double square_signed (double value)
343 : : {
344 [ # # ][ # # ]: 0 : if (value < 0)
345 : 0 : return value * value * -1;
346 : : else
347 : 0 : return value * value;
348 : : }
349 : :
350 : : //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
351 : : //
352 : : // psi is the angle that the wind is blowing *towards*
353 : :
354 : 0 : void FGAtmosphere::SetWindspeed(double speed)
355 : : {
356 [ # # ]: 0 : if (vWindNED.Magnitude() == 0.0) {
357 : 0 : psiw = 0.0;
358 : 0 : vWindNED(eNorth) = speed;
359 : : } else {
360 : 0 : vWindNED(eNorth) = speed * cos(psiw);
361 : 0 : vWindNED(eEast) = speed * sin(psiw);
362 : 0 : vWindNED(eDown) = 0.0;
363 : : }
364 : 0 : }
365 : :
366 : : //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
367 : :
368 : 1 : double FGAtmosphere::GetWindspeed(void) const
369 : : {
370 : 1 : return vWindNED.Magnitude();
371 : : }
372 : :
373 : : //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
374 : : //
375 : : // psi is the angle that the wind is blowing *towards*
376 : :
377 : 0 : void FGAtmosphere::SetWindPsi(double dir)
378 : : {
379 : 0 : double mag = GetWindspeed();
380 : 0 : psiw = dir;
381 : 0 : SetWindspeed(mag);
382 : 0 : }
383 : :
384 : : //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
385 : :
386 : 0 : void FGAtmosphere::Turbulence(void)
387 : : {
388 : 0 : double DeltaT = rate*FDMExec->GetDeltaT();
389 : :
390 [ # # # # ]: 0 : switch (turbType) {
391 : : case ttStandard: {
392 : : // TurbGain = TurbGain * TurbGain * 100.0; // what is this!?
393 : :
394 : 0 : vDirectiondAccelDt(eX) = 1 - 2.0*(double(rand())/double(RAND_MAX));
395 : 0 : vDirectiondAccelDt(eY) = 1 - 2.0*(double(rand())/double(RAND_MAX));
396 : 0 : vDirectiondAccelDt(eZ) = 1 - 2.0*(double(rand())/double(RAND_MAX));
397 : :
398 : 0 : MagnitudedAccelDt = 1 - 2.0*(double(rand())/double(RAND_MAX)) - Magnitude;
399 : : // Scale the magnitude so that it moves
400 : : // away from the peaks
401 : : MagnitudedAccelDt = ((MagnitudedAccelDt - Magnitude) /
402 : 0 : (1 + fabs(Magnitude)));
403 : 0 : MagnitudeAccel += MagnitudedAccelDt*TurbRate*DeltaT;
404 : 0 : Magnitude += MagnitudeAccel*DeltaT;
405 : 0 : Magnitude = fabs(Magnitude);
406 : :
407 : 0 : vDirectiondAccelDt.Normalize();
408 : :
409 : : // deemphasise non-vertical forces
410 : 0 : vDirectiondAccelDt(eX) = square_signed(vDirectiondAccelDt(eX));
411 : 0 : vDirectiondAccelDt(eY) = square_signed(vDirectiondAccelDt(eY));
412 : :
413 : 0 : vDirectionAccel += vDirectiondAccelDt*TurbRate*DeltaT;
414 : 0 : vDirectionAccel.Normalize();
415 : 0 : vDirection += vDirectionAccel*DeltaT;
416 : :
417 : 0 : vDirection.Normalize();
418 : :
419 : : // Diminish turbulence within three wingspans
420 : : // of the ground
421 : 0 : vTurbulenceNED = TurbGain * Magnitude * vDirection;
422 : 0 : double HOverBMAC = Auxiliary->GetHOverBMAC();
423 [ # # ]: 0 : if (HOverBMAC < 3.0)
424 : 0 : vTurbulenceNED *= (HOverBMAC / 3.0) * (HOverBMAC / 3.0);
425 : :
426 : : // I don't believe these next two statements calculate the proper gradient over
427 : : // the aircraft body. One reason is because this has no relationship with the
428 : : // orientation or velocity of the aircraft, which it must have. What is vTurbulenceGrad
429 : : // supposed to represent? And the direction and magnitude of the turbulence can change,
430 : : // so both accelerations need to be accounted for, no?
431 : :
432 : : // Need to determine the turbulence change in body axes between two time points.
433 : :
434 : 0 : vTurbulenceGrad = TurbGain*MagnitudeAccel * vDirection;
435 : 0 : vBodyTurbGrad = Propagate->GetTl2b()*vTurbulenceGrad;
436 : :
437 [ # # ]: 0 : if (Aircraft->GetWingSpan() > 0) {
438 : 0 : vTurbPQR(eP) = vBodyTurbGrad(eY)/Aircraft->GetWingSpan();
439 : : } else {
440 : 0 : vTurbPQR(eP) = vBodyTurbGrad(eY)/30.0;
441 : : }
442 : : // if (Aircraft->GetHTailArm() != 0.0)
443 : : // vTurbPQR(eQ) = vBodyTurbGrad(eZ)/Aircraft->GetHTailArm();
444 : : // else
445 : : // vTurbPQR(eQ) = vBodyTurbGrad(eZ)/10.0;
446 : :
447 [ # # ]: 0 : if (Aircraft->GetVTailArm() > 0)
448 : 0 : vTurbPQR(eR) = vBodyTurbGrad(eX)/Aircraft->GetVTailArm();
449 : : else
450 : 0 : vTurbPQR(eR) = vBodyTurbGrad(eX)/10.0;
451 : :
452 : : // Clear the horizontal forces
453 : : // actually felt by the plane, now
454 : : // that we've used them to calculate
455 : : // moments.
456 : : // Why? (JSB)
457 : : // vTurbulenceNED(eX) = 0.0;
458 : : // vTurbulenceNED(eY) = 0.0;
459 : :
460 : : break;
461 : : }
462 : : case ttBerndt: { // This is very experimental and incomplete at the moment.
463 : :
464 : 0 : vDirectiondAccelDt(eX) = GaussianRandomNumber();
465 : 0 : vDirectiondAccelDt(eY) = GaussianRandomNumber();
466 : 0 : vDirectiondAccelDt(eZ) = GaussianRandomNumber();
467 : : /*
468 : : MagnitudedAccelDt = GaussianRandomNumber();
469 : : MagnitudeAccel += MagnitudedAccelDt * DeltaT;
470 : : Magnitude += MagnitudeAccel * DeltaT;
471 : : */
472 : 0 : Magnitude += GaussianRandomNumber() * DeltaT;
473 : :
474 : 0 : vDirectiondAccelDt.Normalize();
475 : 0 : vDirectionAccel += TurbRate * vDirectiondAccelDt * DeltaT;
476 : 0 : vDirectionAccel.Normalize();
477 : 0 : vDirection += vDirectionAccel*DeltaT;
478 : :
479 : : // Diminish z-vector within two wingspans of the ground
480 : 0 : double HOverBMAC = Auxiliary->GetHOverBMAC();
481 [ # # ]: 0 : if (HOverBMAC < 2.0) vDirection(eZ) *= HOverBMAC / 2.0;
482 : :
483 : 0 : vDirection.Normalize();
484 : :
485 : 0 : vTurbulenceNED = TurbGain*Magnitude * vDirection;
486 : 0 : vTurbulenceGrad = TurbGain*MagnitudeAccel * vDirection;
487 : :
488 : 0 : vBodyTurbGrad = Propagate->GetTl2b() * vTurbulenceGrad;
489 : 0 : vTurbPQR(eP) = vBodyTurbGrad(eY) / Aircraft->GetWingSpan();
490 [ # # ]: 0 : if (Aircraft->GetHTailArm() > 0)
491 : 0 : vTurbPQR(eQ) = vBodyTurbGrad(eZ) / Aircraft->GetHTailArm();
492 : : else
493 : 0 : vTurbPQR(eQ) = vBodyTurbGrad(eZ) / 10.0;
494 : :
495 [ # # ]: 0 : if (Aircraft->GetVTailArm() > 0)
496 : 0 : vTurbPQR(eR) = vBodyTurbGrad(eX) / Aircraft->GetVTailArm();
497 : : else
498 : 0 : vTurbPQR(eR) = vBodyTurbGrad(eX)/10.0;
499 : :
500 : : break;
501 : : }
502 : : case ttCulp: {
503 : :
504 : 0 : vTurbPQR(eP) = wind_from_clockwise;
505 [ # # ]: 0 : if (TurbGain == 0.0) return;
506 : :
507 : : // keep the inputs within allowable limts for this model
508 [ # # ]: 0 : if (TurbGain < 0.0) TurbGain = 0.0;
509 [ # # ]: 0 : if (TurbGain > 1.0) TurbGain = 1.0;
510 [ # # ]: 0 : if (TurbRate < 0.0) TurbRate = 0.0;
511 [ # # ]: 0 : if (TurbRate > 30.0) TurbRate = 30.0;
512 [ # # ]: 0 : if (Rhythmicity < 0.0) Rhythmicity = 0.0;
513 [ # # ]: 0 : if (Rhythmicity > 1.0) Rhythmicity = 1.0;
514 : :
515 : : // generate a sine wave corresponding to turbulence rate in hertz
516 : 0 : double time = FDMExec->GetSimTime();
517 : 0 : double sinewave = sin( time * TurbRate * 6.283185307 );
518 : :
519 : 0 : double random = 0.0;
520 [ # # ]: 0 : if (target_time == 0.0) {
521 : 0 : strength = random = 1 - 2.0*(double(rand())/double(RAND_MAX));
522 : 0 : target_time = time + 0.71 + (random * 0.5);
523 : : }
524 [ # # ]: 0 : if (time > target_time) {
525 : 0 : spike = 1.0;
526 : 0 : target_time = 0.0;
527 : : }
528 : :
529 : : // max vertical wind speed in fps, corresponds to TurbGain = 1.0
530 : 0 : double max_vs = 40;
531 : :
532 : 0 : vTurbulenceNED(1) = vTurbulenceNED(2) = vTurbulenceNED(3) = 0.0;
533 : 0 : double delta = strength * max_vs * TurbGain * (1-Rhythmicity) * spike;
534 : :
535 : : // Vertical component of turbulence.
536 : 0 : vTurbulenceNED(3) = sinewave * max_vs * TurbGain * Rhythmicity;
537 : 0 : vTurbulenceNED(3)+= delta;
538 : 0 : double HOverBMAC = Auxiliary->GetHOverBMAC();
539 [ # # ]: 0 : if (HOverBMAC < 3.0)
540 : 0 : vTurbulenceNED(3) *= HOverBMAC * 0.3333;
541 : :
542 : : // Yaw component of turbulence.
543 : 0 : vTurbulenceNED(1) = sin( delta * 3.0 );
544 : 0 : vTurbulenceNED(2) = cos( delta * 3.0 );
545 : :
546 : : // Roll component of turbulence. Clockwise vortex causes left roll.
547 : 0 : vTurbPQR(eP) += delta * 0.04;
548 : :
549 : 0 : spike = spike * 0.9;
550 : : break;
551 : : }
552 : : default:
553 : : break;
554 : : }
555 : : }
556 : :
557 : : //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
558 : :
559 : 0 : void FGAtmosphere::UseExternal(void)
560 : : {
561 : 0 : temperature=&exTemperature;
562 : 0 : pressure=&exPressure;
563 : 0 : density=&exDensity;
564 : 0 : useExternal=true;
565 : 0 : }
566 : :
567 : : //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
568 : :
569 : 0 : void FGAtmosphere::UseInternal(void)
570 : : {
571 : 1 : temperature=&intTemperature;
572 : 1 : pressure=&intPressure;
573 : 1 : density=&intDensity;
574 : 1 : useExternal=false;
575 : 0 : }
576 : :
577 : : //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
578 : :
579 : 1 : void FGAtmosphere::bind(void)
580 : : {
581 : : typedef double (FGAtmosphere::*PMF)(int) const;
582 : : typedef double (FGAtmosphere::*PMFv)(void) const;
583 : : typedef int (FGAtmosphere::*PMFt)(void) const;
584 : : typedef void (FGAtmosphere::*PMFd)(int,double);
585 : : typedef void (FGAtmosphere::*PMFi)(int);
586 : 1 : PropertyManager->Tie("atmosphere/T-R", this, (PMFv)&FGAtmosphere::GetTemperature);
587 : 1 : PropertyManager->Tie("atmosphere/rho-slugs_ft3", this, (PMFv)&FGAtmosphere::GetDensity);
588 : 1 : PropertyManager->Tie("atmosphere/P-psf", this, (PMFv)&FGAtmosphere::GetPressure);
589 : 1 : PropertyManager->Tie("atmosphere/a-fps", this, &FGAtmosphere::GetSoundSpeed);
590 : 1 : PropertyManager->Tie("atmosphere/T-sl-R", this, &FGAtmosphere::GetTemperatureSL);
591 : 1 : PropertyManager->Tie("atmosphere/rho-sl-slugs_ft3", this, &FGAtmosphere::GetDensitySL);
592 : 1 : PropertyManager->Tie("atmosphere/P-sl-psf", this, &FGAtmosphere::GetPressureSL);
593 : 1 : PropertyManager->Tie("atmosphere/a-sl-fps", this, &FGAtmosphere::GetSoundSpeedSL);
594 : 1 : PropertyManager->Tie("atmosphere/theta", this, &FGAtmosphere::GetTemperatureRatio);
595 : 1 : PropertyManager->Tie("atmosphere/sigma", this, &FGAtmosphere::GetDensityRatio);
596 : 1 : PropertyManager->Tie("atmosphere/delta", this, &FGAtmosphere::GetPressureRatio);
597 : 1 : PropertyManager->Tie("atmosphere/a-ratio", this, &FGAtmosphere::GetSoundSpeedRatio);
598 : 1 : PropertyManager->Tie("atmosphere/psiw-rad", this, &FGAtmosphere::GetWindPsi, &FGAtmosphere::SetWindPsi);
599 : 1 : PropertyManager->Tie("atmosphere/delta-T", this, &FGAtmosphere::GetDeltaT, &FGAtmosphere::SetDeltaT);
600 : 1 : PropertyManager->Tie("atmosphere/T-sl-dev-F", this, &FGAtmosphere::GetSLTempDev, &FGAtmosphere::SetSLTempDev);
601 : 1 : PropertyManager->Tie("atmosphere/density-altitude", this, &FGAtmosphere::GetDensityAltitude);
602 : :
603 : : PropertyManager->Tie("atmosphere/wind-north-fps", this, eNorth, (PMF)&FGAtmosphere::GetWindNED,
604 : 1 : (PMFd)&FGAtmosphere::SetWindNED);
605 : : PropertyManager->Tie("atmosphere/wind-east-fps", this, eEast, (PMF)&FGAtmosphere::GetWindNED,
606 : 1 : (PMFd)&FGAtmosphere::SetWindNED);
607 : : PropertyManager->Tie("atmosphere/wind-down-fps", this, eDown, (PMF)&FGAtmosphere::GetWindNED,
608 : 1 : (PMFd)&FGAtmosphere::SetWindNED);
609 : : PropertyManager->Tie("atmosphere/wind-mag-fps", this, &FGAtmosphere::GetWindspeed,
610 : 1 : &FGAtmosphere::SetWindspeed);
611 : 1 : PropertyManager->Tie("atmosphere/total-wind-north-fps", this, eNorth, (PMF)&FGAtmosphere::GetTotalWindNED);
612 : 1 : PropertyManager->Tie("atmosphere/total-wind-east-fps", this, eEast, (PMF)&FGAtmosphere::GetTotalWindNED);
613 : 1 : PropertyManager->Tie("atmosphere/total-wind-down-fps", this, eDown, (PMF)&FGAtmosphere::GetTotalWindNED);
614 : :
615 : : PropertyManager->Tie("atmosphere/gust-north-fps", this, eNorth, (PMF)&FGAtmosphere::GetGustNED,
616 : 1 : (PMFd)&FGAtmosphere::SetGustNED);
617 : : PropertyManager->Tie("atmosphere/gust-east-fps", this, eEast, (PMF)&FGAtmosphere::GetGustNED,
618 : 1 : (PMFd)&FGAtmosphere::SetGustNED);
619 : : PropertyManager->Tie("atmosphere/gust-down-fps", this, eDown, (PMF)&FGAtmosphere::GetGustNED,
620 : 1 : (PMFd)&FGAtmosphere::SetGustNED);
621 : :
622 : : PropertyManager->Tie("atmosphere/turb-north-fps", this, eNorth, (PMF)&FGAtmosphere::GetTurbNED,
623 : 1 : (PMFd)&FGAtmosphere::SetTurbNED);
624 : : PropertyManager->Tie("atmosphere/turb-east-fps", this, eEast, (PMF)&FGAtmosphere::GetTurbNED,
625 : 1 : (PMFd)&FGAtmosphere::SetTurbNED);
626 : : PropertyManager->Tie("atmosphere/turb-down-fps", this, eDown, (PMF)&FGAtmosphere::GetTurbNED,
627 : 1 : (PMFd)&FGAtmosphere::SetTurbNED);
628 : :
629 : 1 : PropertyManager->Tie("atmosphere/p-turb-rad_sec", this,1, (PMF)&FGAtmosphere::GetTurbPQR);
630 : 1 : PropertyManager->Tie("atmosphere/q-turb-rad_sec", this,2, (PMF)&FGAtmosphere::GetTurbPQR);
631 : 1 : PropertyManager->Tie("atmosphere/r-turb-rad_sec", this,3, (PMF)&FGAtmosphere::GetTurbPQR);
632 : 2 : PropertyManager->Tie("atmosphere/turb-type", this, (PMFt)&FGAtmosphere::GetTurbType, (PMFi)&FGAtmosphere::SetTurbType);
633 : 1 : PropertyManager->Tie("atmosphere/turb-rate", this, &FGAtmosphere::GetTurbRate, &FGAtmosphere::SetTurbRate);
634 : 1 : PropertyManager->Tie("atmosphere/turb-gain", this, &FGAtmosphere::GetTurbGain, &FGAtmosphere::SetTurbGain);
635 : : PropertyManager->Tie("atmosphere/turb-rhythmicity", this, &FGAtmosphere::GetRhythmicity,
636 : 1 : &FGAtmosphere::SetRhythmicity);
637 : 1 : }
638 : :
639 : : //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
640 : : // The bitmasked value choices are as follows:
641 : : // unset: In this case (the default) JSBSim would only print
642 : : // out the normally expected messages, essentially echoing
643 : : // the config files as they are read. If the environment
644 : : // variable is not set, debug_lvl is set to 1 internally
645 : : // 0: This requests JSBSim not to output any messages
646 : : // whatsoever.
647 : : // 1: This value explicity requests the normal JSBSim
648 : : // startup messages
649 : : // 2: This value asks for a message to be printed out when
650 : : // a class is instantiated
651 : : // 4: When this value is set, a message is displayed when a
652 : : // FGModel object executes its Run() method
653 : : // 8: When this value is set, various runtime state variables
654 : : // are printed out periodically
655 : : // 16: When set various parameters are sanity checked and
656 : : // a message is printed out when they go out of bounds
657 : :
658 : 54010 : void FGAtmosphere::Debug(int from)
659 : : {
660 [ + - ]: 54010 : if (debug_lvl <= 0) return;
661 : :
662 : 54010 : if (debug_lvl & 1) { // Standard console startup message output
663 : : if (from == 0) { // Constructor
664 : : }
665 : : }
666 [ - + ]: 54010 : if (debug_lvl & 2 ) { // Instantiation/Destruction notification
667 [ # # ]: 0 : if (from == 0) cout << "Instantiated: FGAtmosphere" << endl;
668 [ # # ]: 0 : if (from == 1) cout << "Destroyed: FGAtmosphere" << endl;
669 : : }
670 : 54010 : if (debug_lvl & 4 ) { // Run() method entry print for FGModel-derived objects
671 : : }
672 : 54010 : if (debug_lvl & 8 ) { // Runtime state variables
673 : : }
674 : 54010 : if (debug_lvl & 16) { // Sanity checking
675 : : }
676 [ - + ]: 54010 : if (debug_lvl & 128) { // Turbulence
677 [ # # ][ # # ]: 0 : if (first_pass && from == 2) {
678 : 0 : first_pass = false;
679 : : cout << "vTurbulenceNED(X), vTurbulenceNED(Y), vTurbulenceNED(Z), "
680 : : << "vTurbulenceGrad(X), vTurbulenceGrad(Y), vTurbulenceGrad(Z), "
681 : : << "vDirection(X), vDirection(Y), vDirection(Z), "
682 : : << "Magnitude, "
683 : 0 : << "vTurbPQR(P), vTurbPQR(Q), vTurbPQR(R), " << endl;
684 : : }
685 [ # # ]: 0 : if (from == 2) {
686 : 0 : cout << vTurbulenceNED << ", " << vTurbulenceGrad << ", " << vDirection << ", " << Magnitude << ", " << vTurbPQR << endl;
687 : : }
688 : : }
689 [ - + ]: 54010 : if (debug_lvl & 64) {
690 [ # # ]: 0 : if (from == 0) { // Constructor
691 : 0 : cout << IdSrc << endl;
692 : 0 : cout << IdHdr << endl;
693 : : }
694 : : }
695 : : }
696 : :
697 [ + + ][ + - ]: 12 : } // namespace JSBSim
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