Purpose: Models the atmosphere
Called by: FGSimExec
- ------------- Copyright (C) 1999 Jon S. Berndt (jsb@hal-pc.org) -------------
+ ------------- Copyright (C) 1999 Jon S. Berndt (jon@jsbsim.org) -------------
This program is free software; you can redistribute it and/or modify it under
the terms of the GNU Lesser General Public License as published by the Free Software
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
#include "FGAtmosphere.h"
-#include <FGState.h>
-#include <FGFDMExec.h>
#include "FGAircraft.h"
#include "FGPropagate.h"
#include "FGInertial.h"
-#include <input_output/FGPropertyManager.h>
+#include "FGAuxiliary.h"
+#include "FGFDMExec.h"
+#include "input_output/FGPropertyManager.h"
+#include <iostream>
+#include <cstdlib>
+
+using namespace std;
namespace JSBSim {
-static const char *IdSrc = "$Id$";
+static const char *IdSrc = "$Id: FGAtmosphere.cpp,v 1.38 2010/09/16 11:01:24 jberndt Exp $";
static const char *IdHdr = ID_ATMOSPHERE;
/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
CLASS IMPLEMENTATION
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
-
FGAtmosphere::FGAtmosphere(FGFDMExec* fdmex) : FGModel(fdmex)
{
Name = "FGAtmosphere";
h = 0.0;
psiw = 0.0;
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.
+ htab[1]= 36089.0;
+ htab[2]= 65617.0;
+ htab[3]=104987.0;
+ htab[4]=154199.0;
+ htab[5]=167322.0;
+ htab[6]=232940.0;
+ htab[7]=278385.0; //ft.
MagnitudedAccelDt = MagnitudeAccel = Magnitude = 0.0;
-// turbType = ttNone;
- turbType = ttStandard;
-// turbType = ttBerndt;
- TurbGain = 0.0;
- TurbRate = 1.0;
+// SetTurbType( ttCulp );
+ SetTurbType( ttNone );
+ TurbGain = 1.0;
+ TurbRate = 10.0;
+ Rhythmicity = 0.1;
+ spike = target_time = strength = 0.0;
+ wind_from_clockwise = 0.0;
+ SutherlandConstant = 198.72; // deg Rankine
+ Beta = 2.269690E-08; // slug/(sec ft R^0.5)
T_dev_sl = T_dev = delta_T = 0.0;
StandardTempOnly = false;
+ first_pass = true;
+ vGustNED.InitMatrix();
+ vTurbulenceNED.InitMatrix();
+
+ // Milspec turbulence model
+ windspeed_at_20ft = 0.;
+ probability_of_exceedence_index = 0;
+ POE_Table = new FGTable(7,12);
+ // this is Figure 7 from p. 49 of MIL-F-8785C
+ // rows: probability of exceedance curve index, cols: altitude in ft
+ *POE_Table
+ << 500.0 << 1750.0 << 3750.0 << 7500.0 << 15000.0 << 25000.0 << 35000.0 << 45000.0 << 55000.0 << 65000.0 << 75000.0 << 80000.0
+ << 1 << 3.2 << 2.2 << 1.5 << 0.0 << 0.0 << 0.0 << 0.0 << 0.0 << 0.0 << 0.0 << 0.0 << 0.0
+ << 2 << 4.2 << 3.6 << 3.3 << 1.6 << 0.0 << 0.0 << 0.0 << 0.0 << 0.0 << 0.0 << 0.0 << 0.0
+ << 3 << 6.6 << 6.9 << 7.4 << 6.7 << 4.6 << 2.7 << 0.4 << 0.0 << 0.0 << 0.0 << 0.0 << 0.0
+ << 4 << 8.6 << 9.6 << 10.6 << 10.1 << 8.0 << 6.6 << 5.0 << 4.2 << 2.7 << 0.0 << 0.0 << 0.0
+ << 5 << 11.8 << 13.0 << 16.0 << 15.1 << 11.6 << 9.7 << 8.1 << 8.2 << 7.9 << 4.9 << 3.2 << 2.1
+ << 6 << 15.6 << 17.6 << 23.0 << 23.6 << 22.1 << 20.0 << 16.0 << 15.1 << 12.1 << 7.9 << 6.2 << 5.1
+ << 7 << 18.7 << 21.5 << 28.4 << 30.2 << 30.7 << 31.0 << 25.2 << 23.1 << 17.5 << 10.7 << 8.4 << 7.2;
bind();
Debug(0);
FGAtmosphere::~FGAtmosphere()
{
- unbind();
Debug(1);
}
bool FGAtmosphere::InitModel(void)
{
- FGModel::InitModel();
+ if (!FGModel::InitModel()) return false;
UseInternal(); // this is the default
if (FGModel::Run()) return true;
if (FDMExec->Holding()) return false;
+ RunPreFunctions();
+
T_dev = 0.0;
- h = Propagate->Geth();
+ h = Propagate->GetAltitudeASL();
if (!useExternal) {
Calculate(h);
CalculateDerived();
}
+ RunPostFunctions();
+
Debug(2);
return false;
}
void FGAtmosphere::Calculate(double altitude)
{
double slope, reftemp, refpress;
- int i = 0;
+ int i = lastIndex;
- i = lastIndex;
if (altitude < htab[lastIndex]) {
if (altitude <= 0) {
i = 0;
}
switch(i) {
- case 1: // 36089 ft.
+ case 0: // Sea level
+ slope = -0.00356616; // R/ft.
+ reftemp = 518.67; // in degrees Rankine, 288.15 Kelvin
+ refpress = 2116.22; // psf
+ //refdens = 0.00237767; // slugs/cubic ft.
+ break;
+ case 1: // 36089 ft. or 11 km
slope = 0;
- reftemp = 389.97;
- refpress = 472.452;
+ reftemp = 389.97; // in degrees Rankine, 216.65 Kelvin
+ refpress = 472.763;
//refdens = 0.000706032;
break;
- case 2: // 65616 ft.
+ case 2: // 65616 ft. or 20 km
slope = 0.00054864;
- reftemp = 389.97;
+ reftemp = 389.97; // in degrees Rankine, 216.65 Kelvin
refpress = 114.636;
//refdens = 0.000171306;
break;
- case 3: // 104986 ft.
- slope = 0.00153619;
- reftemp = 411.57;
- refpress = 8.36364;
+ case 3: // 104986 ft. or 32 km
+ slope = 0.001536192;
+ reftemp = 411.57; // in degrees Rankine, 228.65 Kelvin
+ refpress = 18.128;
//refdens = 1.18422e-05;
break;
- case 4: // 154199 ft.
+ case 4: // 154199 ft. 47 km
slope = 0;
- reftemp = 487.17;
- refpress = 0.334882;
+ reftemp = 487.17; // in degrees Rankine, 270.65 Kelvin
+ refpress = 2.316;
//refdens = 4.00585e-7;
break;
- case 5: // 170603 ft.
- slope = -0.00109728;
- reftemp = 487.17;
- refpress = 0.683084;
+ case 5: // 167322 ft. or 51 km
+ slope = -0.001536192;
+ reftemp = 487.17; // in degrees Rankine, 270.65 Kelvin
+ refpress = 1.398;
//refdens = 8.17102e-7;
break;
- case 6: // 200131 ft.
- slope = -0.00219456;
- reftemp = 454.17;
- refpress = 0.00684986;
+ case 6: // 232940 ft. or 71 km
+ slope = -0.00109728;
+ reftemp = 386.368; // in degrees Rankine, 214.649 Kelvin
+ refpress = 0.0826;
//refdens = 8.77702e-9;
break;
- case 7: // 259186 ft.
+ case 7: // 278385 ft. or 84.8520 km
slope = 0;
- reftemp = 325.17;
- refpress = 0.000122276;
+ reftemp = 336.5; // in degrees Rankine, 186.94 Kelvin
+ refpress = 0.00831;
//refdens = 2.19541e-10;
break;
- case 0:
default: // sea level
slope = -0.00356616; // R/ft.
- reftemp = 518.67; // R
+ reftemp = 518.67; // in degrees Rankine, 288.15 Kelvin
refpress = 2116.22; // psf
//refdens = 0.00237767; // slugs/cubic ft.
break;
intPressure = refpress*pow(intTemperature/reftemp,-Inertial->SLgravity()/(slope*Reng));
intDensity = intPressure/(Reng*intTemperature);
}
-
+
lastIndex=i;
}
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
// Calculate parameters derived from T, P and rho
+// Sum gust and turbulence values in NED frame into the wind vector.
void FGAtmosphere::CalculateDerived(void)
{
T_dev = (*temperature) - GetTemperature(h);
- density_altitude = h + T_dev * 66.7;
- if (turbType == ttStandard) {
- Turbulence();
- vWindNED += vTurbulence;
- }
- if (vWindNED(1) != 0.0) psiw = atan2( vWindNED(2), vWindNED(1) );
+ if (T_dev == 0.0) density_altitude = h;
+ else density_altitude = 518.67/0.00356616 * (1.0 - pow(GetDensityRatio(),0.235));
+
+ if (turbType != ttNone) Turbulence();
+
+ vTotalWindNED = vWindNED + vGustNED + vTurbulenceNED;
+
+ // psiw (Wind heading) is the direction the wind is blowing towards
+ if (vWindNED(eX) != 0.0) psiw = atan2( vWindNED(eY), vWindNED(eX) );
if (psiw < 0) psiw += 2*M_PI;
soundspeed = sqrt(SHRatio*Reng*(*temperature));
+
+ intViscosity = Beta * pow(intTemperature, 1.5) / (SutherlandConstant + intTemperature);
+ intKinematicViscosity = intViscosity / intDensity;
}
return value * value;
}
+/// simply square a value
+static inline double sqr(double x) { return x*x; }
+
+//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+//
+// psi is the angle that the wind is blowing *towards*
+
+void FGAtmosphere::SetWindspeed(double speed)
+{
+ if (vWindNED.Magnitude() == 0.0) {
+ psiw = 0.0;
+ vWindNED(eNorth) = speed;
+ } else {
+ vWindNED(eNorth) = speed * cos(psiw);
+ vWindNED(eEast) = speed * sin(psiw);
+ vWindNED(eDown) = 0.0;
+ }
+}
+
+//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+double FGAtmosphere::GetWindspeed(void) const
+{
+ return vWindNED.Magnitude();
+}
+
+//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+//
+// psi is the angle that the wind is blowing *towards*
+
+void FGAtmosphere::SetWindPsi(double dir)
+{
+ double mag = GetWindspeed();
+ psiw = dir;
+ SetWindspeed(mag);
+}
+
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
void FGAtmosphere::Turbulence(void)
{
+ double DeltaT = rate*FDMExec->GetDeltaT();
+
switch (turbType) {
case ttStandard: {
+ // TurbGain = TurbGain * TurbGain * 100.0; // what is this!?
+
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));
// away from the peaks
MagnitudedAccelDt = ((MagnitudedAccelDt - Magnitude) /
(1 + fabs(Magnitude)));
- MagnitudeAccel += MagnitudedAccelDt*rate*TurbRate*State->Getdt();
- Magnitude += MagnitudeAccel*rate*State->Getdt();
+ MagnitudeAccel += MagnitudedAccelDt*TurbRate*DeltaT;
+ Magnitude += MagnitudeAccel*DeltaT;
+ Magnitude = fabs(Magnitude);
vDirectiondAccelDt.Normalize();
vDirectiondAccelDt(eX) = square_signed(vDirectiondAccelDt(eX));
vDirectiondAccelDt(eY) = square_signed(vDirectiondAccelDt(eY));
- vDirectionAccel += vDirectiondAccelDt*rate*TurbRate*State->Getdt();
+ vDirectionAccel += vDirectiondAccelDt*TurbRate*DeltaT;
vDirectionAccel.Normalize();
- vDirection += vDirectionAccel*rate*State->Getdt();
+ vDirection += vDirectionAccel*DeltaT;
vDirection.Normalize();
// Diminish turbulence within three wingspans
// of the ground
- vTurbulence = TurbGain * Magnitude * vDirection;
+ vTurbulenceNED = TurbGain * Magnitude * vDirection;
double HOverBMAC = Auxiliary->GetHOverBMAC();
if (HOverBMAC < 3.0)
- vTurbulence *= (HOverBMAC / 3.0) * (HOverBMAC / 3.0);
+ vTurbulenceNED *= (HOverBMAC / 3.0) * (HOverBMAC / 3.0);
- vTurbulenceGrad = TurbGain*MagnitudeAccel * vDirection;
+ // I don't believe these next two statements calculate the proper gradient over
+ // the aircraft body. One reason is because this has no relationship with the
+ // orientation or velocity of the aircraft, which it must have. What is vTurbulenceGrad
+ // supposed to represent? And the direction and magnitude of the turbulence can change,
+ // so both accelerations need to be accounted for, no?
+ // Need to determine the turbulence change in body axes between two time points.
+
+ vTurbulenceGrad = TurbGain*MagnitudeAccel * vDirection;
vBodyTurbGrad = Propagate->GetTl2b()*vTurbulenceGrad;
if (Aircraft->GetWingSpan() > 0) {
// actually felt by the plane, now
// that we've used them to calculate
// moments.
- vTurbulence(eX) = 0.0;
- vTurbulence(eY) = 0.0;
+ // Why? (JSB)
+// vTurbulenceNED(eX) = 0.0;
+// vTurbulenceNED(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();
+ case ttBerndt: { // This is very experimental and incomplete at the moment.
+
+ vDirectiondAccelDt(eX) = GaussianRandomNumber();
+ vDirectiondAccelDt(eY) = GaussianRandomNumber();
+ vDirectiondAccelDt(eZ) = GaussianRandomNumber();
+/*
+ MagnitudedAccelDt = GaussianRandomNumber();
+ MagnitudeAccel += MagnitudedAccelDt * DeltaT;
+ Magnitude += MagnitudeAccel * DeltaT;
+*/
+ Magnitude += GaussianRandomNumber() * DeltaT;
vDirectiondAccelDt.Normalize();
- vDirectionAccel += vDirectiondAccelDt*rate*State->Getdt();
+ vDirectionAccel += TurbRate * vDirectiondAccelDt * DeltaT;
vDirectionAccel.Normalize();
- vDirection += vDirectionAccel*rate*State->Getdt();
+ vDirection += vDirectionAccel*DeltaT;
- // Diminish z-vector within two wingspans
- // of the ground
+ // Diminish z-vector within two wingspans of the ground
double HOverBMAC = Auxiliary->GetHOverBMAC();
- if (HOverBMAC < 2.0)
- vDirection(eZ) *= HOverBMAC / 2.0;
+ if (HOverBMAC < 2.0) vDirection(eZ) *= HOverBMAC / 2.0;
vDirection.Normalize();
- vTurbulence = TurbGain*Magnitude * vDirection;
+ vTurbulenceNED = TurbGain*Magnitude * vDirection;
vTurbulenceGrad = TurbGain*MagnitudeAccel * vDirection;
- vBodyTurbGrad = Propagate->GetTl2b()*vTurbulenceGrad;
- vTurbPQR(eP) = vBodyTurbGrad(eY)/Aircraft->GetWingSpan();
+ vBodyTurbGrad = Propagate->GetTl2b() * vTurbulenceGrad;
+ vTurbPQR(eP) = vBodyTurbGrad(eY) / Aircraft->GetWingSpan();
if (Aircraft->GetHTailArm() > 0)
- vTurbPQR(eQ) = vBodyTurbGrad(eZ)/Aircraft->GetHTailArm();
+ vTurbPQR(eQ) = vBodyTurbGrad(eZ) / Aircraft->GetHTailArm();
else
- vTurbPQR(eQ) = vBodyTurbGrad(eZ)/10.0;
+ vTurbPQR(eQ) = vBodyTurbGrad(eZ) / 10.0;
if (Aircraft->GetVTailArm() > 0)
- vTurbPQR(eR) = vBodyTurbGrad(eX)/Aircraft->GetVTailArm();
+ vTurbPQR(eR) = vBodyTurbGrad(eX) / Aircraft->GetVTailArm();
else
vTurbPQR(eR) = vBodyTurbGrad(eX)/10.0;
break;
}
+ case ttCulp: {
+
+ vTurbPQR(eP) = wind_from_clockwise;
+ if (TurbGain == 0.0) return;
+
+ // keep the inputs within allowable limts for this model
+ if (TurbGain < 0.0) TurbGain = 0.0;
+ if (TurbGain > 1.0) TurbGain = 1.0;
+ if (TurbRate < 0.0) TurbRate = 0.0;
+ if (TurbRate > 30.0) TurbRate = 30.0;
+ if (Rhythmicity < 0.0) Rhythmicity = 0.0;
+ if (Rhythmicity > 1.0) Rhythmicity = 1.0;
+
+ // generate a sine wave corresponding to turbulence rate in hertz
+ double time = FDMExec->GetSimTime();
+ double sinewave = sin( time * TurbRate * 6.283185307 );
+
+ double random = 0.0;
+ if (target_time == 0.0) {
+ strength = random = 1 - 2.0*(double(rand())/double(RAND_MAX));
+ target_time = time + 0.71 + (random * 0.5);
+ }
+ if (time > target_time) {
+ spike = 1.0;
+ target_time = 0.0;
+ }
+
+ // max vertical wind speed in fps, corresponds to TurbGain = 1.0
+ double max_vs = 40;
+
+ vTurbulenceNED(1) = vTurbulenceNED(2) = vTurbulenceNED(3) = 0.0;
+ double delta = strength * max_vs * TurbGain * (1-Rhythmicity) * spike;
+
+ // Vertical component of turbulence.
+ vTurbulenceNED(3) = sinewave * max_vs * TurbGain * Rhythmicity;
+ vTurbulenceNED(3)+= delta;
+ double HOverBMAC = Auxiliary->GetHOverBMAC();
+ if (HOverBMAC < 3.0)
+ vTurbulenceNED(3) *= HOverBMAC * 0.3333;
+
+ // Yaw component of turbulence.
+ vTurbulenceNED(1) = sin( delta * 3.0 );
+ vTurbulenceNED(2) = cos( delta * 3.0 );
+
+ // Roll component of turbulence. Clockwise vortex causes left roll.
+ vTurbPQR(eP) += delta * 0.04;
+
+ spike = spike * 0.9;
+ break;
+ }
+ case ttMilspec:
+ case ttTustin: {
+ // an index of zero means turbulence is disabled
+ if (probability_of_exceedence_index == 0) {
+ vTurbulenceNED(1) = vTurbulenceNED(2) = vTurbulenceNED(3) = 0.0;
+ vTurbPQR(1) = vTurbPQR(2) = vTurbPQR(3) = 0.0;
+ return;
+ }
+
+ // Turbulence model according to MIL-F-8785C (Flying Qualities of Piloted Aircraft)
+ double
+ h = Propagate->GetDistanceAGL(),
+ V = Auxiliary->GetVt(), // true airspeed in ft/s
+ b_w = Aircraft->GetWingSpan(),
+ L_u, L_w, sig_u, sig_w;
+
+ // clip height functions at 10 ft
+ if (h <= 10.) h = 10;
+
+ // Scale lengths L and amplitudes sigma as function of height
+ if (h <= 1000) {
+ L_u = h/pow(0.177 + 0.000823*h, 1.2); // MIL-F-8785c, Fig. 10, p. 55
+ L_w = h;
+ sig_w = 0.1*windspeed_at_20ft;
+ sig_u = sig_w/pow(0.177 + 0.000823*h, 0.4); // MIL-F-8785c, Fig. 11, p. 56
+ } else if (h <= 2000) {
+ // linear interpolation between low altitude and high altitude models
+ L_u = L_w = 1000 + (h-1000.)/1000.*750.;
+ sig_u = sig_w = 0.1*windspeed_at_20ft
+ + (h-1000.)/1000.*(POE_Table->GetValue(probability_of_exceedence_index, h) - 0.1*windspeed_at_20ft);
+ } else {
+ L_u = L_w = 1750.; // MIL-F-8785c, Sec. 3.7.2.1, p. 48
+ sig_u = sig_w = POE_Table->GetValue(probability_of_exceedence_index, h);
+ }
+
+ // keep values from last timesteps
+ // TODO maybe use deque?
+ static double
+ xi_u_km1 = 0, nu_u_km1 = 0,
+ xi_v_km1 = 0, xi_v_km2 = 0, nu_v_km1 = 0, nu_v_km2 = 0,
+ xi_w_km1 = 0, xi_w_km2 = 0, nu_w_km1 = 0, nu_w_km2 = 0,
+ xi_p_km1 = 0, nu_p_km1 = 0,
+ xi_q_km1 = 0, xi_r_km1 = 0;
+
+
+ double
+ T_V = DeltaT, // for compatibility of nomenclature
+ sig_p = 1.9/sqrt(L_w*b_w)*sig_w, // Yeager1998, eq. (8)
+ sig_q = sqrt(M_PI/2/L_w/b_w), // eq. (14)
+ sig_r = sqrt(2*M_PI/3/L_w/b_w), // eq. (17)
+ L_p = sqrt(L_w*b_w)/2.6, // eq. (10)
+ tau_u = L_u/V, // eq. (6)
+ tau_w = L_w/V, // eq. (3)
+ tau_p = L_p/V, // eq. (9)
+ tau_q = 4*b_w/M_PI/V, // eq. (13)
+ tau_r =3*b_w/M_PI/V, // eq. (17)
+ nu_u = GaussianRandomNumber(),
+ nu_v = GaussianRandomNumber(),
+ nu_w = GaussianRandomNumber(),
+ nu_p = GaussianRandomNumber(),
+ xi_u, xi_v, xi_w, xi_p, xi_q, xi_r;
+
+ // values of turbulence NED velocities
+
+ if (turbType == ttTustin) {
+ // the following is the Tustin formulation of Yeager's report
+ double
+ omega_w = V/L_w, // hidden in nomenclature p. 3
+ omega_v = V/L_u, // this is defined nowhere
+ C_BL = 1/tau_u/tan(T_V/2/tau_u), // eq. (19)
+ C_BLp = 1/tau_p/tan(T_V/2/tau_p), // eq. (22)
+ C_BLq = 1/tau_q/tan(T_V/2/tau_q), // eq. (24)
+ C_BLr = 1/tau_r/tan(T_V/2/tau_r); // eq. (26)
+
+ xi_u = -(1 - C_BL*tau_u)/(1 + C_BL*tau_u)*xi_u_km1
+ + sig_u*sqrt(2*tau_u/T_V)/(1 + C_BL*tau_u)*(nu_u + nu_u_km1); // eq. (18)
+ xi_v = -2*(sqr(omega_v) - sqr(C_BL))/sqr(omega_v + C_BL)*xi_v_km1
+ - sqr(omega_v - C_BL)/sqr(omega_v + C_BL) * xi_v_km2
+ + sig_u*sqrt(3*omega_v/T_V)/sqr(omega_v + C_BL)*(
+ (C_BL + omega_v/sqrt(3.))*nu_v
+ + 2/sqrt(3.)*omega_v*nu_v_km1
+ + (omega_v/sqrt(3.) - C_BL)*nu_v_km2); // eq. (20) for v
+ xi_w = -2*(sqr(omega_w) - sqr(C_BL))/sqr(omega_w + C_BL)*xi_w_km1
+ - sqr(omega_w - C_BL)/sqr(omega_w + C_BL) * xi_w_km2
+ + sig_w*sqrt(3*omega_w/T_V)/sqr(omega_w + C_BL)*(
+ (C_BL + omega_w/sqrt(3.))*nu_w
+ + 2/sqrt(3.)*omega_w*nu_w_km1
+ + (omega_w/sqrt(3.) - C_BL)*nu_w_km2); // eq. (20) for w
+ xi_p = -(1 - C_BLp*tau_p)/(1 + C_BLp*tau_p)*xi_p_km1
+ + sig_p*sqrt(2*tau_p/T_V)/(1 + C_BLp*tau_p) * (nu_p + nu_p_km1); // eq. (21)
+ xi_q = -(1 - 4*b_w*C_BLq/M_PI/V)/(1 + 4*b_w*C_BLq/M_PI/V) * xi_q_km1
+ + C_BLq/V/(1 + 4*b_w*C_BLq/M_PI/V) * (xi_w - xi_w_km1); // eq. (23)
+ xi_r = - (1 - 3*b_w*C_BLr/M_PI/V)/(1 + 3*b_w*C_BLr/M_PI/V) * xi_r_km1
+ + C_BLr/V/(1 + 3*b_w*C_BLr/M_PI/V) * (xi_v - xi_v_km1); // eq. (25)
+
+ } else if (turbType == ttMilspec) {
+ // the following is the MIL-STD-1797A formulation
+ // as cited in Yeager's report
+ xi_u = (1 - T_V/tau_u) *xi_u_km1 + sig_u*sqrt(2*T_V/tau_u)*nu_u; // eq. (30)
+ xi_v = (1 - 2*T_V/tau_u)*xi_v_km1 + sig_u*sqrt(4*T_V/tau_u)*nu_v; // eq. (31)
+ xi_w = (1 - 2*T_V/tau_w)*xi_w_km1 + sig_w*sqrt(4*T_V/tau_w)*nu_w; // eq. (32)
+ xi_p = (1 - T_V/tau_p) *xi_p_km1 + sig_p*sqrt(2*T_V/tau_p)*nu_p; // eq. (33)
+ xi_q = (1 - T_V/tau_q) *xi_q_km1 + M_PI/4/b_w*(xi_w - xi_w_km1); // eq. (34)
+ xi_r = (1 - T_V/tau_r) *xi_r_km1 + M_PI/3/b_w*(xi_v - xi_v_km1); // eq. (35)
+ }
+
+ // rotate by wind azimuth and assign the velocities
+ double cospsi = cos(psiw), sinpsi = sin(psiw);
+ vTurbulenceNED(1) = cospsi*xi_u + sinpsi*xi_v;
+ vTurbulenceNED(2) = -sinpsi*xi_u + cospsi*xi_v;
+ vTurbulenceNED(3) = xi_w;
+
+ vTurbPQR(1) = cospsi*xi_p + sinpsi*xi_q;
+ vTurbPQR(2) = -sinpsi*xi_p + cospsi*xi_q;
+ vTurbPQR(3) = xi_r;
+
+ // vTurbPQR is in the body fixed frame, not NED
+ vTurbPQR = Propagate->GetTl2b()*vTurbPQR;
+
+ // hand on the values for the next timestep
+ xi_u_km1 = xi_u; nu_u_km1 = nu_u;
+ xi_v_km2 = xi_v_km1; xi_v_km1 = xi_v; nu_v_km2 = nu_v_km1; nu_v_km1 = nu_v;
+ xi_w_km2 = xi_w_km1; xi_w_km1 = xi_w; nu_w_km2 = nu_w_km1; nu_w_km1 = nu_w;
+ xi_p_km1 = xi_p; nu_p_km1 = nu_p;
+ xi_q_km1 = xi_q;
+ xi_r_km1 = xi_r;
+
+ }
default:
break;
}
{
typedef double (FGAtmosphere::*PMF)(int) const;
typedef double (FGAtmosphere::*PMFv)(void) const;
+ typedef int (FGAtmosphere::*PMFt)(void) const;
+ typedef void (FGAtmosphere::*PMFd)(int,double);
+ typedef void (FGAtmosphere::*PMFi)(int);
PropertyManager->Tie("atmosphere/T-R", this, (PMFv)&FGAtmosphere::GetTemperature);
PropertyManager->Tie("atmosphere/rho-slugs_ft3", this, (PMFv)&FGAtmosphere::GetDensity);
PropertyManager->Tie("atmosphere/P-psf", this, (PMFv)&FGAtmosphere::GetPressure);
PropertyManager->Tie("atmosphere/sigma", this, &FGAtmosphere::GetDensityRatio);
PropertyManager->Tie("atmosphere/delta", this, &FGAtmosphere::GetPressureRatio);
PropertyManager->Tie("atmosphere/a-ratio", this, &FGAtmosphere::GetSoundSpeedRatio);
- PropertyManager->Tie("atmosphere/psiw-rad", this, &FGAtmosphere::GetWindPsi);
+ PropertyManager->Tie("atmosphere/psiw-rad", this, &FGAtmosphere::GetWindPsi, &FGAtmosphere::SetWindPsi);
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/wind-north-fps", this, eNorth, (PMF)&FGAtmosphere::GetWindNED,
+ (PMFd)&FGAtmosphere::SetWindNED);
+ PropertyManager->Tie("atmosphere/wind-east-fps", this, eEast, (PMF)&FGAtmosphere::GetWindNED,
+ (PMFd)&FGAtmosphere::SetWindNED);
+ PropertyManager->Tie("atmosphere/wind-down-fps", this, eDown, (PMF)&FGAtmosphere::GetWindNED,
+ (PMFd)&FGAtmosphere::SetWindNED);
+ PropertyManager->Tie("atmosphere/wind-mag-fps", this, &FGAtmosphere::GetWindspeed,
+ &FGAtmosphere::SetWindspeed);
+ PropertyManager->Tie("atmosphere/total-wind-north-fps", this, eNorth, (PMF)&FGAtmosphere::GetTotalWindNED);
+ PropertyManager->Tie("atmosphere/total-wind-east-fps", this, eEast, (PMF)&FGAtmosphere::GetTotalWindNED);
+ PropertyManager->Tie("atmosphere/total-wind-down-fps", this, eDown, (PMF)&FGAtmosphere::GetTotalWindNED);
+
+ PropertyManager->Tie("atmosphere/gust-north-fps", this, eNorth, (PMF)&FGAtmosphere::GetGustNED,
+ (PMFd)&FGAtmosphere::SetGustNED);
+ PropertyManager->Tie("atmosphere/gust-east-fps", this, eEast, (PMF)&FGAtmosphere::GetGustNED,
+ (PMFd)&FGAtmosphere::SetGustNED);
+ PropertyManager->Tie("atmosphere/gust-down-fps", this, eDown, (PMF)&FGAtmosphere::GetGustNED,
+ (PMFd)&FGAtmosphere::SetGustNED);
+
+ PropertyManager->Tie("atmosphere/turb-north-fps", this, eNorth, (PMF)&FGAtmosphere::GetTurbNED,
+ (PMFd)&FGAtmosphere::SetTurbNED);
+ PropertyManager->Tie("atmosphere/turb-east-fps", this, eEast, (PMF)&FGAtmosphere::GetTurbNED,
+ (PMFd)&FGAtmosphere::SetTurbNED);
+ PropertyManager->Tie("atmosphere/turb-down-fps", this, eDown, (PMF)&FGAtmosphere::GetTurbNED,
+ (PMFd)&FGAtmosphere::SetTurbNED);
+
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);
-}
-
-//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+ PropertyManager->Tie("atmosphere/turb-type", this, (PMFt)&FGAtmosphere::GetTurbType, (PMFi)&FGAtmosphere::SetTurbType);
+ PropertyManager->Tie("atmosphere/turb-rate", this, &FGAtmosphere::GetTurbRate, &FGAtmosphere::SetTurbRate);
+ PropertyManager->Tie("atmosphere/turb-gain", this, &FGAtmosphere::GetTurbGain, &FGAtmosphere::SetTurbGain);
+ PropertyManager->Tie("atmosphere/turb-rhythmicity", this, &FGAtmosphere::GetRhythmicity,
+ &FGAtmosphere::SetRhythmicity);
+
+ PropertyManager->Tie("atmosphere/turbulence/milspec/windspeed_at_20ft_AGL-fps",
+ this, &FGAtmosphere::GetWindspeed20ft,
+ &FGAtmosphere::SetWindspeed20ft);
+ PropertyManager->Tie("atmosphere/turbulence/milspec/severity",
+ this, &FGAtmosphere::GetProbabilityOfExceedence,
+ &FGAtmosphere::SetProbabilityOfExceedence);
-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");
- PropertyManager->Untie("atmosphere/sigma");
- PropertyManager->Untie("atmosphere/delta");
- PropertyManager->Untie("atmosphere/a-ratio");
- 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");
}
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
if (debug_lvl & 16) { // Sanity checking
}
if (debug_lvl & 128) { // Turbulence
- if (frame == 0 && from == 2) {
- cout << "vTurbulence(X), vTurbulence(Y), vTurbulence(Z), "
+ if (first_pass && from == 2) {
+ first_pass = false;
+ cout << "vTurbulenceNED(X), vTurbulenceNED(Y), vTurbulenceNED(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 (from == 2) {
+ cout << vTurbulenceNED << ", " << vTurbulenceGrad << ", " << vDirection << ", " << Magnitude << ", " << vTurbPQR << endl;
}
}
if (debug_lvl & 64) {
projects / flightgear.git / blobdiff