public void SimulateAeroProperties(
out Vector3 aeroForce,
out Vector3 aeroTorque,
Vector3 velocityWorldVector,
double altitude
)
{
var center = new FARCenterQuery();
var dummy = new FARCenterQuery();
//Calculate main gas properties
GasProperties properties = FARAtmosphere.GetGasProperties(vessel, altitude, Planetarium.GetUniversalTime());
if (properties.Pressure <= 0 || properties.Temperature <= 0)
{
aeroForce = Vector3.zero;
aeroTorque = Vector3.zero;
return;
}
float velocityMag = velocityWorldVector.magnitude;
float machNumber = (float)(velocityMag / properties.SpeedOfSound);
float reynoldsNumber = (float)FARAeroUtil.CalculateReynoldsNumber(properties.Density,
Length,
velocityMag,
machNumber,
properties.Temperature,
properties.AdiabaticIndex);
float reynoldsPerLength = reynoldsNumber / (float)Length;
float skinFriction = (float)FARAeroUtil.SkinFrictionDrag(reynoldsNumber, machNumber);
float pseudoKnudsenNumber = machNumber / (reynoldsNumber + machNumber);
if (_currentAeroSections != null)
{
foreach (FARAeroSection curSection in _currentAeroSections)
{
curSection?.PredictionCalculateAeroForces((float)properties.Density,
machNumber,
reynoldsPerLength,
pseudoKnudsenNumber,
skinFriction,
velocityWorldVector,
center);
}
foreach (FARWingAerodynamicModel curWing in _legacyWingModels)
{
if (curWing != null)
{
center.AddForce(curWing.transform.position,
curWing.PrecomputeCenterOfLift(velocityWorldVector,
machNumber,
properties.Density,
dummy));
}
}
}
aeroForce = center.force;
aeroTorque = center.TorqueAt(vessel.CoM);
}
public void GetClCdCmSteady(
InstantConditionSimInput input,
out InstantConditionSimOutput output,
bool clear,
bool reset_stall = false
)
{
output = new InstantConditionSimOutput();
double area = 0;
double MAC = 0;
double b_2 = 0;
Vector3d forward = Vector3.forward;
Vector3d up = Vector3.up;
Vector3d right = Vector3.right;
Vector3d CoM = Vector3d.zero;
if (EditorDriver.editorFacility == EditorFacility.VAB)
{
forward = Vector3.up;
up = -Vector3.forward;
}
double mass = 0;
List <Part> partsList = EditorLogic.SortedShipList;
foreach (Part p in partsList)
{
if (FARAeroUtil.IsNonphysical(p))
{
continue;
}
double partMass = p.mass;
if (p.Resources.Count > 0)
{
partMass += p.GetResourceMass();
}
// If you want to use GetModuleMass, you need to start from p.partInfo.mass, not p.mass
CoM += partMass * (Vector3d)p.transform.TransformPoint(p.CoMOffset);
mass += partMass;
}
CoM /= mass;
// Rodhern: The original reference directions (velocity, liftVector, sideways) did not form an orthonormal
// basis. That in turn produced some counterintuitive calculation results, such as coupled yaw and pitch
// derivatives. A more thorough discussion of the topic can be found on the KSP forums:
// https://forum.kerbalspaceprogram.com/index.php?/topic/19321-131-ferram-aerospace-research-v01591-liepmann-4218/&do=findComment&comment=2781270
// The reference directions have been replaced by new ones that are orthonormal by construction.
// In dkavolis branch Vector3.Cross() and Vector3d.Normalize() are used explicitly. There is no apparent
// benefit to this other than possibly improved readability.
double sinAlpha = Math.Sin(input.alpha * Math.PI / 180);
double cosAlpha = Math.Sqrt(Math.Max(1 - sinAlpha * sinAlpha, 0));
double sinBeta = Math.Sin(input.beta * Math.PI / 180);
double cosBeta = Math.Sqrt(Math.Max(1 - sinBeta * sinBeta, 0));
double sinPhi = Math.Sin(input.phi * Math.PI / 180);
double cosPhi = Math.Sqrt(Math.Max(1 - sinPhi * sinPhi, 0));
double alphaDot = input.alphaDot * Math.PI / 180;
double betaDot = input.betaDot * Math.PI / 180;
double phiDot = input.phiDot * Math.PI / 180;
Vector3d velocity = forward * cosAlpha * cosBeta;
velocity += right * (sinPhi * sinAlpha * cosBeta + cosPhi * sinBeta);
velocity += -up * (cosPhi * sinAlpha * cosBeta - sinPhi * sinBeta);
velocity.Normalize();
Vector3d liftDown = -forward * sinAlpha;
liftDown += right * sinPhi * cosAlpha;
liftDown += -up * cosPhi * cosAlpha;
liftDown.Normalize();
Vector3d sideways = Vector3.Cross(velocity, liftDown);
sideways.Normalize();
Vector3d angVel = forward * (phiDot - sinAlpha * betaDot);
angVel += right * (cosPhi * alphaDot + cosAlpha * sinPhi * betaDot);
angVel += up * (sinPhi * alphaDot - cosAlpha * cosPhi * betaDot);
foreach (FARWingAerodynamicModel w in _wingAerodynamicModel)
{
if (!(w && w.part))
{
continue;
}
w.ComputeForceEditor(velocity, input.machNumber, 2);
if (clear)
{
w.EditorClClear(reset_stall);
}
Vector3d relPos = w.GetAerodynamicCenter() - CoM;
Vector3d vel = velocity + Vector3d.Cross(angVel, relPos);
if (w is FARControllableSurface controllableSurface)
{
controllableSurface.SetControlStateEditor(CoM,
vel,
(float)input.pitchValue,
0,
0,
input.flaps,
input.spoilers);
}
else if (w.isShielded)
{
continue;
}
Vector3d force = w.ComputeForceEditor(vel.normalized, input.machNumber, 2) * 1000;
output.Cl += -Vector3d.Dot(force, liftDown);
output.Cy += Vector3d.Dot(force, sideways);
output.Cd += -Vector3d.Dot(force, velocity);
Vector3d moment = -Vector3d.Cross(relPos, force);
output.Cm += Vector3d.Dot(moment, sideways);
output.Cn += Vector3d.Dot(moment, liftDown);
output.C_roll += Vector3d.Dot(moment, velocity);
area += w.S;
MAC += w.GetMAC() * w.S;
b_2 += w.Getb_2() * w.S;
}
var center = new FARCenterQuery();
foreach (FARAeroSection aeroSection in _currentAeroSections)
{
aeroSection.PredictionCalculateAeroForces(2,
(float)input.machNumber,
10000,
0,
0.005f,
velocity.normalized,
center);
}
Vector3d centerForce = center.force * 1000;
output.Cl += -Vector3d.Dot(centerForce, liftDown);
output.Cy += Vector3d.Dot(centerForce, sideways);
output.Cd += -Vector3d.Dot(centerForce, velocity);
Vector3d centerMoment = -center.TorqueAt(CoM) * 1000;
output.Cm += Vector3d.Dot(centerMoment, sideways);
output.Cn += Vector3d.Dot(centerMoment, liftDown);
output.C_roll += Vector3d.Dot(centerMoment, velocity);
if (area.NearlyEqual(0))
{
area = _maxCrossSectionFromBody;
b_2 = 1;
MAC = _bodyLength;
}
double recipArea = 1 / area;
MAC *= recipArea;
b_2 *= recipArea;
output.Cl *= recipArea;
output.Cd *= recipArea;
output.Cm *= recipArea / MAC;
output.Cy *= recipArea;
output.Cn *= recipArea / b_2;
output.C_roll *= recipArea / b_2;
}
void UpdateAerodynamicCenter()
{
FARCenterQuery aeroSection, dummy;
aeroSection = new FARCenterQuery();
dummy = new FARCenterQuery();
if ((object)EditorLogic.RootPart == null)
{
return;
}
Vector3 vel_base, vel_fuzz;
Transform rootPartTrans = EditorLogic.RootPart.partTransform;
if (EditorDriver.editorFacility == EditorFacility.SPH)
{
vel_base = Vector3.forward;
vel_fuzz = 0.02f * Vector3.up;
}
else
{
vel_base = Vector3.up;
vel_fuzz = -0.02f * Vector3.forward;
}
Vector3 vel = (vel_base - vel_fuzz).normalized;
for (int i = 0; i < _currentAeroSections.Count; i++)
{
FARAeroSection section = _currentAeroSections[i];
section.PredictionCalculateAeroForces(1, 0.5f, 100000, 0, 0.005f, vel, aeroSection);
}
FARBaseAerodynamics.PrecomputeGlobalCenterOfLift(aeroSection, dummy, vel);
Vector3 pos = Vector3.zero;//rootPartTrans.position;
float mass = 0;
for (int i = 0; i < EditorLogic.SortedShipList.Count; i++)
{
Part p = EditorLogic.SortedShipList[i];
float tmpMass = p.mass + p.GetResourceMass();
mass += tmpMass;
pos += p.partTransform.position * tmpMass;
}
pos /= mass;
Vector3 avgForcePos = Vector3.zero;
Vector3 force0, moment0;
force0 = aeroSection.force;
moment0 = aeroSection.TorqueAt(pos);
avgForcePos += aeroSection.GetPos();
//aeroSection.force = -aeroSection.force;
//aeroSection.torque = -aeroSection.torque;
aeroSection.ClearAll();
vel = (vel_base + vel_fuzz).normalized;
for (int i = 0; i < _currentAeroSections.Count; i++)
{
FARAeroSection section = _currentAeroSections[i];
section.PredictionCalculateAeroForces(1, 0.5f, 100000, 0, 0.005f, vel, aeroSection);
}
FARBaseAerodynamics.PrecomputeGlobalCenterOfLift(aeroSection, dummy, vel);
Vector3 force1, moment1;
force1 = aeroSection.force;
moment1 = aeroSection.TorqueAt(pos);
avgForcePos += aeroSection.GetPos();
aeroSection.ClearAll();
avgForcePos *= 0.5f;
Vector3 deltaForce = force1 - force0;
Vector3 deltaMoment = moment1 - moment0;
Vector3 deltaForcePerp = Vector3.ProjectOnPlane(deltaForce, vel_base);
float deltaForcePerpMag = deltaForcePerp.magnitude;
Vector3 deltaForcePerpNorm = deltaForcePerp / deltaForcePerpMag;
Vector3 deltaMomentPerp = deltaMoment - Vector3.Dot(deltaMoment, deltaForcePerpNorm) * deltaForcePerpNorm - Vector3.Project(deltaMoment, vel_base);
//float dist = deltaMomentPerp.magnitude / deltaForcePerpMag;
//vesselRootLocalAeroCenter = vel_base * dist;
vesselRootLocalAeroCenter = deltaMomentPerp.magnitude / deltaForcePerpMag * vel_base * Math.Sign(Vector3.Dot(Vector3.Cross(deltaForce, deltaMoment), vel_base));
//FARLogger.Info("" + dist + " " + deltaMomentPerp.magnitude + " " + deltaForcePerpMag);
//vesselRootLocalAeroCenter += avgForcePos;
//avgForcePos = rootPartTrans.worldToLocalMatrix.MultiplyPoint3x4(avgForcePos);
//vesselRootLocalAeroCenter += Vector3.ProjectOnPlane(avgForcePos, Vector3.up);
//vesselRootLocalAeroCenter = aeroSection.GetPos();
vesselRootLocalAeroCenter += pos;//Vector3.ProjectOnPlane(avgForcePos - pos, vesselRootLocalAeroCenter) + pos;
vesselRootLocalAeroCenter = rootPartTrans.worldToLocalMatrix.MultiplyPoint3x4(vesselRootLocalAeroCenter);
}
public void GetClCdCmSteady(InstantConditionSimInput input, out InstantConditionSimOutput output, bool clear, bool reset_stall = false)
{
output = new InstantConditionSimOutput();
double area = 0;
double MAC = 0;
double b_2 = 0;
Vector3d forward = Vector3.forward;
Vector3d up = Vector3.up;
Vector3d right = Vector3.right;
Vector3d CoM = Vector3d.zero;
double mass = 0;
List <Part> partsList = EditorLogic.SortedShipList;
for (int i = 0; i < partsList.Count; i++)
{
Part p = partsList[i];
if (FARAeroUtil.IsNonphysical(p))
{
continue;
}
double partMass = p.mass;
if (p.Resources.Count > 0)
{
partMass += p.GetResourceMass();
}
//partMass += p.GetModuleMass(p.mass);
// If you want to use GetModuleMass, you need to start from p.partInfo.mass, not p.mass
CoM += partMass * (Vector3d)p.transform.TransformPoint(p.CoMOffset);
mass += partMass;
}
CoM /= mass;
if (EditorDriver.editorFacility == EditorFacility.VAB)
{
forward = Vector3.up;
up = -Vector3.forward;
}
double sinAlpha = Math.Sin(input.alpha * Math.PI / 180);
double cosAlpha = Math.Sqrt(Math.Max(1 - sinAlpha * sinAlpha, 0));
double sinBeta = Math.Sin(input.beta * Math.PI / 180);
double cosBeta = Math.Sqrt(Math.Max(1 - sinBeta * sinBeta, 0));
double sinPhi = Math.Sin(input.phi * Math.PI / 180);
double cosPhi = Math.Sqrt(Math.Max(1 - sinPhi * sinPhi, 0));
double alphaDot = input.alphaDot * Math.PI / 180;
double betaDot = input.betaDot * Math.PI / 180;
double phiDot = input.phiDot * Math.PI / 180;
Vector3d AngVel = (phiDot - sinAlpha * betaDot) * forward;
AngVel += (cosPhi * alphaDot + cosAlpha * sinPhi * betaDot) * right;
AngVel += (sinPhi * alphaDot - cosAlpha * cosPhi * betaDot) * up;
Vector3d velocity = forward * cosAlpha * cosBeta;
velocity += right * (sinPhi * cosAlpha * cosBeta + cosPhi * sinBeta);
velocity += -up * cosPhi * (sinAlpha * cosBeta + sinBeta);
velocity.Normalize();
//this is negative wrt the ground
Vector3d liftVector = -forward * sinAlpha + right * sinPhi * cosAlpha - up * cosPhi * cosAlpha;
Vector3d sideways = Vector3.Cross(velocity, liftVector).normalized;
for (int i = 0; i < _wingAerodynamicModel.Count; i++)
{
FARWingAerodynamicModel w = _wingAerodynamicModel[i];
if (!(w && w.part))
{
continue;
}
w.ComputeForceEditor(velocity.normalized, input.machNumber, 2);
if (clear)
{
w.EditorClClear(reset_stall);
}
Vector3d relPos = w.GetAerodynamicCenter() - CoM;
Vector3d vel = velocity + Vector3d.Cross(AngVel, relPos);
if (w is FARControllableSurface)
{
(w as FARControllableSurface).SetControlStateEditor(CoM, vel, (float)input.pitchValue, 0, 0, input.flaps, input.spoilers);
}
else if (w.isShielded)
{
continue;
}
//w.ComputeForceEditor(velocity, input.machNumber); //do this just to get the AC right
Vector3d force = w.ComputeForceEditor(vel.normalized, input.machNumber, 2) * 1000;
output.Cl += -Vector3d.Dot(force, liftVector);
output.Cy += Vector3d.Dot(force, sideways);
output.Cd += -Vector3d.Dot(force, velocity);
Vector3d moment = -Vector3d.Cross(relPos, force);
output.Cm += Vector3d.Dot(moment, sideways);
output.Cn += Vector3d.Dot(moment, liftVector);
output.C_roll += Vector3d.Dot(moment, velocity);
//w.ComputeClCdEditor(vel.normalized, input.machNumber);
/*double tmpCl = w.GetCl() * w.S;
* output.Cl += tmpCl * -Vector3d.Dot(w.GetLiftDirection(), liftVector);
* output.Cy += tmpCl * -Vector3d.Dot(w.GetLiftDirection(), sideways);
* double tmpCd = w.GetCd() * w.S;
* output.Cd += tmpCd;
* output.Cm += tmpCl * Vector3d.Dot((relPos), velocity) * -Vector3d.Dot(w.GetLiftDirection(), liftVector) + tmpCd * -Vector3d.Dot((relPos), liftVector);
* output.Cn += tmpCd * Vector3d.Dot((relPos), sideways) + tmpCl * Vector3d.Dot((relPos), velocity) * -Vector3d.Dot(w.GetLiftDirection(), sideways);
* output.C_roll += tmpCl * Vector3d.Dot((relPos), sideways) * -Vector3d.Dot(w.GetLiftDirection(), liftVector);*/
area += w.S;
MAC += w.GetMAC() * w.S;
b_2 += w.Getb_2() * w.S;
}
FARCenterQuery center = new FARCenterQuery();
for (int i = 0; i < _currentAeroSections.Count; i++)
{
_currentAeroSections[i].PredictionCalculateAeroForces(2, (float)input.machNumber, 10000, 0.005f, velocity.normalized, center);
}
Vector3d centerForce = center.force * 1000;
output.Cl += -Vector3d.Dot(centerForce, liftVector);
output.Cy += Vector3d.Dot(centerForce, sideways);
output.Cd += -Vector3d.Dot(centerForce, velocity);
Vector3d centerMoment = -center.TorqueAt(CoM) * 1000;
output.Cm += Vector3d.Dot(centerMoment, sideways);
output.Cn += Vector3d.Dot(centerMoment, liftVector);
output.C_roll += Vector3d.Dot(centerMoment, velocity);
/*for (int i = 0; i < FARAeroUtil.CurEditorParts.Count; i++)
* {
* Part p = FARAeroUtil.CurEditorParts[i];
* if (FARAeroUtil.IsNonphysical(p))
* continue;
*
* Vector3 part_pos = p.transform.TransformPoint(p.CoMOffset) - CoM;
* double partMass = p.mass;
* if (p.Resources.Count > 0)
* partMass += p.GetResourceMass();
*
* double stock_drag = partMass * p.maximum_drag * FlightGlobals.DragMultiplier * 1000;
* output.Cd += stock_drag;
* output.Cm += stock_drag * -Vector3d.Dot(part_pos, liftVector);
* output.Cn += stock_drag * Vector3d.Dot(part_pos, sideways);
* }*/
if (area == 0)
{
area = _maxCrossSectionFromBody;
b_2 = 1;
MAC = _bodyLength;
}
double recipArea = 1 / area;
MAC *= recipArea;
b_2 *= recipArea;
output.Cl *= recipArea;
output.Cd *= recipArea;
output.Cm *= recipArea / MAC;
output.Cy *= recipArea;
output.Cn *= recipArea / b_2;
output.C_roll *= recipArea / b_2;
}
private void UpdateAerodynamicCenter()
{
var aeroSection = new FARCenterQuery();
var dummy = new FARCenterQuery();
if (EditorLogic.RootPart is null)
{
return;
}
Vector3 vel_base, vel_fuzz;
Transform rootPartTrans = EditorLogic.RootPart.partTransform;
if (EditorDriver.editorFacility == EditorFacility.SPH)
{
vel_base = Vector3.forward;
vel_fuzz = 0.02f * Vector3.up;
}
else
{
vel_base = Vector3.up;
vel_fuzz = -0.02f * Vector3.forward;
}
Vector3 vel = (vel_base - vel_fuzz).normalized;
foreach (FARAeroSection section in _currentAeroSections)
{
section.PredictionCalculateAeroForces(1, 0.5f, 100000, 0, 0.005f, vel, aeroSection);
}
FARBaseAerodynamics.PrecomputeGlobalCenterOfLift(aeroSection, dummy, vel, 1);
Vector3 pos = Vector3.zero;
float mass = 0;
foreach (Part p in EditorLogic.SortedShipList)
{
float tmpMass = p.mass + p.GetResourceMass();
mass += tmpMass;
pos += p.partTransform.position * tmpMass;
}
pos /= mass;
Vector3 force0 = aeroSection.force;
Vector3 moment0 = aeroSection.TorqueAt(pos);
aeroSection.ClearAll();
vel = (vel_base + vel_fuzz).normalized;
foreach (FARAeroSection section in _currentAeroSections)
{
section.PredictionCalculateAeroForces(1, 0.5f, 100000, 0, 0.005f, vel, aeroSection);
}
FARBaseAerodynamics.PrecomputeGlobalCenterOfLift(aeroSection, dummy, vel, 1);
Vector3 force1 = aeroSection.force;
Vector3 moment1 = aeroSection.TorqueAt(pos);
aeroSection.ClearAll();
Vector3 deltaForce = force1 - force0;
Vector3 deltaMoment = moment1 - moment0;
Vector3 deltaForcePerp = Vector3.ProjectOnPlane(deltaForce, vel_base);
float deltaForcePerpMag = deltaForcePerp.magnitude;
Vector3 deltaForcePerpNorm = deltaForcePerp / deltaForcePerpMag;
Vector3 deltaMomentPerp = deltaMoment -
Vector3.Dot(deltaMoment, deltaForcePerpNorm) * deltaForcePerpNorm -
Vector3.Project(deltaMoment, vel_base);
vesselRootLocalAeroCenter = deltaMomentPerp.magnitude /
deltaForcePerpMag *
Math.Sign(Vector3.Dot(Vector3.Cross(deltaForce, deltaMoment), vel_base)) *
vel_base;
vesselRootLocalAeroCenter += pos;
vesselRootLocalAeroCenter = rootPartTrans.worldToLocalMatrix.MultiplyPoint3x4(vesselRootLocalAeroCenter);
}
public void SimulateAeroProperties(
out Vector3 aeroForce,
out Vector3 aeroTorque,
Vector3 velocityWorldVector,
double altitude
)
{
var center = new FARCenterQuery();
var dummy = new FARCenterQuery();
CelestialBody body = vessel.mainBody; //Calculate main gas properties
float pressure = (float)body.GetPressure(altitude);
float temperature = (float)body.GetTemperature(altitude);
float density = (float)body.GetDensity(pressure, temperature);
float speedOfSound = (float)body.GetSpeedOfSound(pressure, density);
if (pressure <= 0 || temperature <= 0 || density <= 0 || speedOfSound <= 0)
{
aeroForce = Vector3.zero;
aeroTorque = Vector3.zero;
return;
}
float velocityMag = velocityWorldVector.magnitude;
float machNumber = velocityMag / speedOfSound;
float reynoldsNumber =
(float)FARAeroUtil.CalculateReynoldsNumber(density,
Length,
velocityMag,
machNumber,
temperature,
body.atmosphereAdiabaticIndex);
float reynoldsPerLength = reynoldsNumber / (float)Length;
float skinFriction = (float)FARAeroUtil.SkinFrictionDrag(reynoldsNumber, machNumber);
float pseudoKnudsenNumber = machNumber / (reynoldsNumber + machNumber);
if (_currentAeroSections != null)
{
foreach (FARAeroSection curSection in _currentAeroSections)
{
curSection?.PredictionCalculateAeroForces(density,
machNumber,
reynoldsPerLength,
pseudoKnudsenNumber,
skinFriction,
velocityWorldVector,
center);
}
foreach (FARWingAerodynamicModel curWing in _legacyWingModels)
{
if (!(curWing is null))
{
center.AddForce(curWing.transform.position,
curWing.PrecomputeCenterOfLift(velocityWorldVector,
machNumber,
density,
dummy));
}
}
}
aeroForce = center.force;
aeroTorque = center.TorqueAt(vessel.CoM);
}