bool FGAerodynamics::Run(bool Holding)
{
if (FGModel::Run(Holding)) return true;
if (Holding) return false; // if paused don't execute
unsigned int axis_ctr, ctr;
const double twovel=2*in.Vt;
RunPreFunctions();
// calculate some oft-used quantities for speed
if (twovel != 0) {
bi2vel = in.Wingspan / twovel;
ci2vel = in.Wingchord / twovel;
}
alphaw = in.Alpha + in.Wingincidence;
qbar_area = in.Wingarea * in.Qbar;
if (alphaclmax != 0) {
if (in.Alpha > 0.85*alphaclmax) {
impending_stall = 10*(in.Alpha/alphaclmax - 0.85);
} else {
impending_stall = 0;
}
}
if (alphahystmax != 0.0 && alphahystmin != 0.0) {
if (in.Alpha > alphahystmax) {
stall_hyst = 1;
} else if (in.Alpha < alphahystmin) {
stall_hyst = 0;
}
}
vFw.InitMatrix();
vFnative.InitMatrix();
for (axis_ctr = 0; axis_ctr < 3; axis_ctr++) {
for (ctr=0; ctr < AeroFunctions[axis_ctr].size(); ctr++) {
vFnative(axis_ctr+1) += AeroFunctions[axis_ctr][ctr]->GetValue();
}
}
// Note that we still need to convert to wind axes here, because it is
// used in the L/D calculation, and we still may want to look at Lift
// and Drag.
switch (axisType) {
case atBodyXYZ: // Forces already in body axes; no manipulation needed
vFw = in.Tb2w*vFnative;
vForces = vFnative;
break;
case atLiftDrag: // Copy forces into wind axes
vFw = vFnative;
vFw(eDrag)*=-1; vFw(eLift)*=-1;
vForces = in.Tw2b*vFw;
break;
case atAxialNormal: // Convert native forces into Axial|Normal|Side system
vFw = in.Tb2w*vFnative;
vFnative(eX)*=-1; vFnative(eZ)*=-1;
vForces = vFnative;
break;
default:
cerr << endl << " A proper axis type has NOT been selected. Check "
<< "your aerodynamics definition." << endl;
exit(-1);
}
// Calculate lift coefficient squared
if ( in.Qbar > 0) {
clsq = vFw(eLift) / (in.Wingarea*in.Qbar);
clsq *= clsq;
}
// Calculate lift Lift over Drag
if ( fabs(vFw(eDrag)) > 0.0) lod = fabs( vFw(eLift) / vFw(eDrag) );
// Calculate aerodynamic reference point shift, if any. The shift
// takes place in the structual axis. That is, if the shift is positive,
// it is towards the back (tail) of the vehicle. The AeroRPShift
// function should be non-dimensionalized by the wing chord. The
// calculated vDeltaRP will be in feet.
if (AeroRPShift) vDeltaRP(eX) = AeroRPShift->GetValue()*in.Wingchord;
vDXYZcg(eX) = in.RPBody(eX) - vDeltaRP(eX); // vDeltaRP is given in the structural frame
vDXYZcg(eY) = in.RPBody(eY) + vDeltaRP(eY);
vDXYZcg(eZ) = in.RPBody(eZ) - vDeltaRP(eZ);
vMoments = vDXYZcg*vForces; // M = r X F
for (axis_ctr = 0; axis_ctr < 3; axis_ctr++) {
for (ctr = 0; ctr < AeroFunctions[axis_ctr+3].size(); ctr++) {
vMoments(axis_ctr+1) += AeroFunctions[axis_ctr+3][ctr]->GetValue();
}
}
RunPostFunctions();
return false;
}
bool FGAerodynamics::Run(bool Holding)
{
if (FGModel::Run(Holding)) return true;
if (Holding) return false; // if paused don't execute
unsigned int axis_ctr, ctr;
const double twovel=2*in.Vt;
RunPreFunctions();
// calculate some oft-used quantities for speed
if (twovel != 0) {
bi2vel = in.Wingspan / twovel;
ci2vel = in.Wingchord / twovel;
}
alphaw = in.Alpha + in.Wingincidence;
qbar_area = in.Wingarea * in.Qbar;
if (alphaclmax != 0) {
if (in.Alpha > 0.85*alphaclmax) {
impending_stall = 10*(in.Alpha/alphaclmax - 0.85);
} else {
impending_stall = 0;
}
}
if (alphahystmax != 0.0 && alphahystmin != 0.0) {
if (in.Alpha > alphahystmax) {
stall_hyst = 1;
} else if (in.Alpha < alphahystmin) {
stall_hyst = 0;
}
}
vFw.InitMatrix();
vFwAtCG.InitMatrix();
vFnative.InitMatrix();
vFnativeAtCG.InitMatrix();
for (axis_ctr = 0; axis_ctr < 3; axis_ctr++) {
for (ctr=0; ctr < AeroFunctions[axis_ctr].size(); ctr++) {
vFnative(axis_ctr+1) += AeroFunctions[axis_ctr][ctr]->GetValue();
}
}
for (axis_ctr = 0; axis_ctr < 3; axis_ctr++) {
for (ctr=0; ctr < AeroFunctionsAtCG[axis_ctr].size(); ctr++) {
vFnativeAtCG(axis_ctr+1) += AeroFunctionsAtCG[axis_ctr][ctr]->GetValue();
}
}
// Note that we still need to convert to wind axes here, because it is
// used in the L/D calculation, and we still may want to look at Lift
// and Drag.
// JSB 4/27/12 - After use, convert wind axes to produce normal lift
// and drag values - not negative ones!
// As a clarification, JSBSim assumes that drag and lift values are defined
// in wind axes - BUT with a 180 rotation about the Y axis. That is, lift and
// drag will be positive up and aft, respectively, so that they are reported
// as positive numbers. However, the wind axes themselves assume that the X
// and Z forces are positive forward and down.
switch (axisType) {
case atBodyXYZ: // Forces already in body axes; no manipulation needed
vFw = in.Tb2w*vFnative;
vForces = vFnative;
vFw(eDrag)*=-1; vFw(eLift)*=-1;
vFwAtCG = in.Tb2w*vFnativeAtCG;
vForcesAtCG = vFnativeAtCG;
vFwAtCG(eDrag)*=-1; vFwAtCG(eLift)*=-1;
break;
case atLiftDrag: // Copy forces into wind axes
vFw = vFnative;
vFw(eDrag)*=-1; vFw(eLift)*=-1;
vForces = in.Tw2b*vFw;
vFw(eDrag)*=-1; vFw(eLift)*=-1;
vFwAtCG = vFnativeAtCG;
vFwAtCG(eDrag)*=-1; vFwAtCG(eLift)*=-1;
vForcesAtCG = in.Tw2b*vFwAtCG;
vFwAtCG(eDrag)*=-1; vFwAtCG(eLift)*=-1;
break;
case atAxialNormal: // Convert native forces into Axial|Normal|Side system
vFw = in.Tb2w*vFnative;
vFnative(eX)*=-1; vFnative(eZ)*=-1;
vForces = vFnative;
vFwAtCG = in.Tb2w*vFnativeAtCG;
vFnativeAtCG(eX)*=-1; vFnativeAtCG(eZ)*=-1;
vForcesAtCG = vFnativeAtCG;
break;
default:
cerr << endl << " A proper axis type has NOT been selected. Check "
<< "your aerodynamics definition." << endl;
exit(-1);
}
// Calculate lift coefficient squared
if ( in.Qbar > 0) {
clsq = (vFw(eLift) + vFwAtCG(eLift))/ (in.Wingarea*in.Qbar);
clsq *= clsq;
}
// Calculate lift Lift over Drag
if ( fabs(vFw(eDrag) + vFwAtCG(eDrag)) > 0.0)
lod = fabs( (vFw(eLift) + vFwAtCG(eLift))/ (vFw(eDrag) + vFwAtCG(eDrag)));
// Calculate aerodynamic reference point shift, if any. The shift
// takes place in the structual axis. That is, if the shift is positive,
// it is towards the back (tail) of the vehicle. The AeroRPShift
// function should be non-dimensionalized by the wing chord. The
// calculated vDeltaRP will be in feet.
if (AeroRPShift) vDeltaRP(eX) = AeroRPShift->GetValue()*in.Wingchord;
vDXYZcg(eX) = in.RPBody(eX) - vDeltaRP(eX); // vDeltaRP is given in the structural frame
vDXYZcg(eY) = in.RPBody(eY) + vDeltaRP(eY);
vDXYZcg(eZ) = in.RPBody(eZ) - vDeltaRP(eZ);
vMomentsMRC.InitMatrix();
for (axis_ctr = 0; axis_ctr < 3; axis_ctr++) {
for (ctr = 0; ctr < AeroFunctions[axis_ctr+3].size(); ctr++) {
vMomentsMRC(axis_ctr+1) += AeroFunctions[axis_ctr+3][ctr]->GetValue();
}
}
vMoments = vMomentsMRC + vDXYZcg*vForces; // M = r X F
// Now add the "at CG" values to base forces - after the moments have been transferred
vForces += vForcesAtCG;
vFnative += vFnativeAtCG;
vFw += vFwAtCG;
RunPostFunctions();
return false;
}
