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Merge pull request #1288 from openrocket/revert-1273-normalize-CD-names

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Revert "Refer to drag coefficient consistently as CD"
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Joe Pfeiffer 2022-04-10 09:41:35 -06:00 committed by GitHub
commit 507dbb7c36
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9 changed files with 61 additions and 57 deletions
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22
core/src/net/sf/openrocket/aerodynamics/AerodynamicForces.java
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@ -51,7 +51,7 @@ public class AerodynamicForces implements Cloneable, Monitorable {
/** Axial drag coefficient, CA */ /** Axial drag coefficient, CA */
private double CDaxial = Double.NaN; private double Caxial = Double.NaN;
/** Total drag force coefficient, parallel to the airflow. */ /** Total drag force coefficient, parallel to the airflow. */
private double CD = Double.NaN; private double CD = Double.NaN;
@ -181,13 +181,13 @@ public class AerodynamicForces implements Cloneable, Monitorable {
return CrollForce; return CrollForce;
} }
public void setCDaxial(double cdaxial) { public void setCaxial(double caxial) {
CDaxial = cdaxial; Caxial = caxial;
modID++; modID++;
} }
public double getCDaxial() { public double getCaxial() {
return CDaxial; return Caxial;
} }
public void setCD(double cD) { public void setCD(double cD) {
@ -277,7 +277,7 @@ public class AerodynamicForces implements Cloneable, Monitorable {
setCroll(Double.NaN); setCroll(Double.NaN);
setCrollDamp(Double.NaN); setCrollDamp(Double.NaN);
setCrollForce(Double.NaN); setCrollForce(Double.NaN);
setCDaxial(Double.NaN); setCaxial(Double.NaN);
setCD(Double.NaN); setCD(Double.NaN);
setPitchDampingMoment(Double.NaN); setPitchDampingMoment(Double.NaN);
setYawDampingMoment(Double.NaN); setYawDampingMoment(Double.NaN);
@ -299,7 +299,7 @@ public class AerodynamicForces implements Cloneable, Monitorable {
setCroll(0); setCroll(0);
setCrollDamp(0); setCrollDamp(0);
setCrollForce(0); setCrollForce(0);
setCDaxial(0); setCaxial(0);
setCD(0); setCD(0);
setPitchDampingMoment(0); setPitchDampingMoment(0);
setYawDampingMoment(0); setYawDampingMoment(0);
@ -334,7 +334,7 @@ public class AerodynamicForces implements Cloneable, Monitorable {
MathUtil.equals(this.getCroll(), other.getCroll()) && MathUtil.equals(this.getCroll(), other.getCroll()) &&
MathUtil.equals(this.getCrollDamp(), other.getCrollDamp()) && MathUtil.equals(this.getCrollDamp(), other.getCrollDamp()) &&
MathUtil.equals(this.getCrollForce(), other.getCrollForce()) && MathUtil.equals(this.getCrollForce(), other.getCrollForce()) &&
MathUtil.equals(this.getCDaxial(), other.getCDaxial()) && MathUtil.equals(this.getCaxial(), other.getCaxial()) &&
MathUtil.equals(this.getCD(), other.getCD()) && MathUtil.equals(this.getCD(), other.getCD()) &&
MathUtil.equals(this.getPressureCD(), other.getPressureCD()) && MathUtil.equals(this.getPressureCD(), other.getPressureCD()) &&
MathUtil.equals(this.getBaseCD(), other.getBaseCD()) && MathUtil.equals(this.getBaseCD(), other.getBaseCD()) &&
@ -346,7 +346,7 @@ public class AerodynamicForces implements Cloneable, Monitorable {
@Override @Override
public int hashCode() { public int hashCode() {
return (int) (1000*(this.getCD()+this.getCDaxial()+this.getCNa())) + this.getCP().hashCode(); return (int) (1000*(this.getCD()+this.getCaxial()+this.getCNa())) + this.getCP().hashCode();
} }
@ -373,8 +373,8 @@ public class AerodynamicForces implements Cloneable, Monitorable {
if (!Double.isNaN(getCroll())) if (!Double.isNaN(getCroll()))
text += "Croll:" + getCroll() + ","; text += "Croll:" + getCroll() + ",";
if (!Double.isNaN(getCDaxial())) if (!Double.isNaN(getCaxial()))
text += "CDaxial:" + getCDaxial() + ","; text += "Caxial:" + getCaxial() + ",";
if (!Double.isNaN(getCD())) if (!Double.isNaN(getCD()))
text += "CD:" + getCD() + ","; text += "CD:" + getCD() + ",";

34
core/src/net/sf/openrocket/aerodynamics/BarrowmanCalculator.java
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@ -82,11 +82,11 @@ public class BarrowmanCalculator extends AbstractAerodynamicCalculator {
// Calculate non-axial force data // Calculate non-axial force data
calculateForceAnalysis(conditions, configuration.getRocket(), instMap, eachMap, assemblyMap, warnings); calculateForceAnalysis(conditions, configuration.getRocket(), instMap, eachMap, assemblyMap, warnings);
// Calculate drag coefficient data // Calculate friction data
AerodynamicForces rocketForces = assemblyMap.get(configuration.getRocket()); AerodynamicForces rocketForces = assemblyMap.get(configuration.getRocket());
rocketForces.setFrictionCD(calculateFrictionCD(configuration, conditions, eachMap, warnings)); rocketForces.setFrictionCD(calculateFrictionDrag(configuration, conditions, eachMap, warnings));
rocketForces.setPressureCD(calculatePressureCD(configuration, conditions, eachMap, warnings)); rocketForces.setPressureCD(calculatePressureDrag(configuration, conditions, eachMap, warnings));
rocketForces.setBaseCD(calculateBaseCD(configuration, conditions, eachMap, warnings)); rocketForces.setBaseCD(calculateBaseDrag(configuration, conditions, eachMap, warnings));
Map<RocketComponent, AerodynamicForces> finalMap = new LinkedHashMap<>(); Map<RocketComponent, AerodynamicForces> finalMap = new LinkedHashMap<>();
for(final RocketComponent comp : instMap.keySet()){ for(final RocketComponent comp : instMap.keySet()){
@ -117,7 +117,7 @@ public class BarrowmanCalculator extends AbstractAerodynamicCalculator {
f.setFrictionCD(0); f.setFrictionCD(0);
f.setCD(f.getBaseCD() + f.getPressureCD() + f.getFrictionCD()); f.setCD(f.getBaseCD() + f.getPressureCD() + f.getFrictionCD());
f.setCDaxial(calculateAxialCD(conditions, f.getCD())); f.setCaxial(calculateAxialDrag(conditions, f.getCD()));
finalMap.put(comp, f); finalMap.put(comp, f);
} }
@ -177,13 +177,13 @@ public class BarrowmanCalculator extends AbstractAerodynamicCalculator {
AerodynamicForces total = calculateNonAxialForces(configuration, conditions, warnings); AerodynamicForces total = calculateNonAxialForces(configuration, conditions, warnings);
// Calculate friction data // Calculate friction data
total.setFrictionCD(calculateFrictionCD(configuration, conditions, null, warnings)); total.setFrictionCD(calculateFrictionDrag(configuration, conditions, null, warnings));
total.setPressureCD(calculatePressureCD(configuration, conditions, null, warnings)); total.setPressureCD(calculatePressureDrag(configuration, conditions, null, warnings));
total.setBaseCD(calculateBaseCD(configuration, conditions, null, warnings)); total.setBaseCD(calculateBaseDrag(configuration, conditions, null, warnings));
total.setCD(total.getFrictionCD() + total.getPressureCD() + total.getBaseCD()); total.setCD(total.getFrictionCD() + total.getPressureCD() + total.getBaseCD());
total.setCDaxial(calculateAxialCD(conditions, total.getCD())); total.setCaxial(calculateAxialDrag(conditions, total.getCD()));
// Calculate pitch and yaw damping moments // Calculate pitch and yaw damping moments
calculateDampingMoments(configuration, conditions, total); calculateDampingMoments(configuration, conditions, total);
@ -322,7 +322,7 @@ public class BarrowmanCalculator extends AbstractAerodynamicCalculator {
* @param set Set to handle * @param set Set to handle
* @return friction drag for entire rocket * @return friction drag for entire rocket
*/ */
private double calculateFrictionCD(FlightConfiguration configuration, FlightConditions conditions, private double calculateFrictionDrag(FlightConfiguration configuration, FlightConditions conditions,
Map<RocketComponent, AerodynamicForces> map, WarningSet set) { Map<RocketComponent, AerodynamicForces> map, WarningSet set) {
double c1 = 1.0, c2 = 1.0; double c1 = 1.0, c2 = 1.0;
@ -523,7 +523,9 @@ public class BarrowmanCalculator extends AbstractAerodynamicCalculator {
if (map != null) { if (map != null) {
map.get(c).setFrictionCD(cd / conditions.getRefArea()); map.get(c).setFrictionCD(cd / conditions.getRefArea());
} }
} }
} }
} }
@ -553,7 +555,7 @@ public class BarrowmanCalculator extends AbstractAerodynamicCalculator {
* @param warningSet all current warnings * @param warningSet all current warnings
* @return * @return
*/ */
private double calculatePressureCD(FlightConfiguration configuration, FlightConditions conditions, private double calculatePressureDrag(FlightConfiguration configuration, FlightConditions conditions,
Map<RocketComponent, AerodynamicForces> forceMap, WarningSet warningSet) { Map<RocketComponent, AerodynamicForces> forceMap, WarningSet warningSet) {
double stagnation, base, total; double stagnation, base, total;
@ -576,7 +578,7 @@ public class BarrowmanCalculator extends AbstractAerodynamicCalculator {
for(InstanceContext context: contextList ) { for(InstanceContext context: contextList ) {
// Pressure fore drag // Pressure fore drag
double cd = calcMap.get(c).calculatePressureCD(conditions, stagnation, base, double cd = calcMap.get(c).calculatePressureDragForce(conditions, stagnation, base,
warningSet); warningSet);
total += cd; total += cd;
@ -622,7 +624,7 @@ public class BarrowmanCalculator extends AbstractAerodynamicCalculator {
* @param warnings all current warnings * @param warnings all current warnings
* @return * @return
*/ */
private double calculateBaseCD(FlightConfiguration configuration, FlightConditions conditions, private double calculateBaseDrag(FlightConfiguration configuration, FlightConditions conditions,
Map<RocketComponent, AerodynamicForces> map, WarningSet warnings) { Map<RocketComponent, AerodynamicForces> map, WarningSet warnings) {
double base, total; double base, total;
@ -685,6 +687,8 @@ public class BarrowmanCalculator extends AbstractAerodynamicCalculator {
return total; return total;
} }
/** /**
* gets CD by the speed * gets CD by the speed
* @param m Mach number for calculation * @param m Mach number for calculation
@ -735,13 +739,13 @@ public class BarrowmanCalculator extends AbstractAerodynamicCalculator {
/** /**
* Calculate the axial drag coefficient from the total drag coefficient. * Calculate the axial drag from the total drag coefficient.
* *
* @param conditions * @param conditions
* @param cd * @param cd
* @return * @return
*/ */
private double calculateAxialCD(FlightConditions conditions, double cd) { private double calculateAxialDrag(FlightConditions conditions, double cd) {
double aoa = MathUtil.clamp(conditions.getAOA(), 0, Math.PI); double aoa = MathUtil.clamp(conditions.getAOA(), 0, Math.PI);
double mul; double mul;

22
core/src/net/sf/openrocket/aerodynamics/barrowman/FinSetCalc.java
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@ -623,11 +623,11 @@ public class FinSetCalc extends RocketComponentCalc {
// } // }
@Override @Override
public double calculatePressureCD(FlightConditions conditions, public double calculatePressureDragForce(FlightConditions conditions,
double stagnationCD, double baseCD, WarningSet warnings) { double stagnationCD, double baseCD, WarningSet warnings) {
double mach = conditions.getMach(); double mach = conditions.getMach();
double cd = 0; double drag = 0;
// Pressure fore-drag // Pressure fore-drag
if (crossSection == FinSet.CrossSection.AIRFOIL || if (crossSection == FinSet.CrossSection.AIRFOIL ||
@ -635,34 +635,34 @@ public class FinSetCalc extends RocketComponentCalc {
// Round leading edge // Round leading edge
if (mach < 0.9) { if (mach < 0.9) {
cd = Math.pow(1 - pow2(mach), -0.417) - 1; drag = Math.pow(1 - pow2(mach), -0.417) - 1;
} else if (mach < 1) { } else if (mach < 1) {
cd = 1 - 1.785 * (mach - 0.9); drag = 1 - 1.785 * (mach - 0.9);
} else { } else {
cd = 1.214 - 0.502 / pow2(mach) + 0.1095 / pow2(pow2(mach)); drag = 1.214 - 0.502 / pow2(mach) + 0.1095 / pow2(pow2(mach));
} }
} else if (crossSection == FinSet.CrossSection.SQUARE) { } else if (crossSection == FinSet.CrossSection.SQUARE) {
cd = stagnationCD; drag = stagnationCD;
} else { } else {
throw new UnsupportedOperationException("Unsupported fin profile: " + crossSection); throw new UnsupportedOperationException("Unsupported fin profile: " + crossSection);
} }
// Slanted leading edge // Slanted leading edge
cd *= pow2(cosGammaLead); drag *= pow2(cosGammaLead);
// Trailing edge drag // Trailing edge drag
if (crossSection == FinSet.CrossSection.SQUARE) { if (crossSection == FinSet.CrossSection.SQUARE) {
cd += baseCD; drag += baseCD;
} else if (crossSection == FinSet.CrossSection.ROUNDED) { } else if (crossSection == FinSet.CrossSection.ROUNDED) {
cd += baseCD / 2; drag += baseCD / 2;
} }
// Airfoil assumed to have zero base drag // Airfoil assumed to have zero base drag
// Scale to correct reference area // Scale to correct reference area
cd *= cd * span * thickness / conditions.getRefArea(); drag *= span * thickness / conditions.getRefArea();
return cd; return drag;
} }
private void calculateInterferenceFinCount(FinSet component) { private void calculateInterferenceFinCount(FinSet component) {

2
core/src/net/sf/openrocket/aerodynamics/barrowman/LaunchLugCalc.java
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@ -31,7 +31,7 @@ public class LaunchLugCalc extends RocketComponentCalc {
} }
@Override @Override
public double calculatePressureCD(FlightConditions conditions, public double calculatePressureDragForce(FlightConditions conditions,
double stagnationCD, double baseCD, WarningSet warnings) { double stagnationCD, double baseCD, WarningSet warnings) {
return CDmul*stagnationCD * refArea / conditions.getRefArea(); return CDmul*stagnationCD * refArea / conditions.getRefArea();

2
core/src/net/sf/openrocket/aerodynamics/barrowman/RocketComponentCalc.java
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@ -39,6 +39,6 @@ public abstract class RocketComponentCalc {
* @param warnings set in which to store possible warnings * @param warnings set in which to store possible warnings
* @return the pressure drag of the component * @return the pressure drag of the component
*/ */
public abstract double calculatePressureCD(FlightConditions conditions, public abstract double calculatePressureDragForce(FlightConditions conditions,
double stagnationCD, double baseCD, WarningSet warnings); double stagnationCD, double baseCD, WarningSet warnings);
} }

2
core/src/net/sf/openrocket/aerodynamics/barrowman/SymmetricComponentCalc.java
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@ -179,7 +179,7 @@ public class SymmetricComponentCalc extends RocketComponentCalc {
private LinearInterpolator interpolator = null; private LinearInterpolator interpolator = null;
@Override @Override
public double calculatePressureCD(FlightConditions conditions, public double calculatePressureDragForce(FlightConditions conditions,
double stagnationCD, double baseCD, WarningSet warnings) { double stagnationCD, double baseCD, WarningSet warnings) {
// Check for simple cases first // Check for simple cases first

22
core/src/net/sf/openrocket/aerodynamics/barrowman/TubeFinSetCalc.java
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@ -622,11 +622,11 @@ public class TubeFinSetCalc extends RocketComponentCalc {
// } // }
@Override @Override
public double calculatePressureCD(FlightConditions conditions, public double calculatePressureDragForce(FlightConditions conditions,
double stagnationCD, double baseCD, WarningSet warnings) { double stagnationCD, double baseCD, WarningSet warnings) {
double mach = conditions.getMach(); double mach = conditions.getMach();
double cd = 0; double drag = 0;
// Pressure fore-drag // Pressure fore-drag
if (crossSection == FinSet.CrossSection.AIRFOIL || if (crossSection == FinSet.CrossSection.AIRFOIL ||
@ -634,34 +634,34 @@ public class TubeFinSetCalc extends RocketComponentCalc {
// Round leading edge // Round leading edge
if (mach < 0.9) { if (mach < 0.9) {
cd = Math.pow(1 - pow2(mach), -0.417) - 1; drag = Math.pow(1 - pow2(mach), -0.417) - 1;
} else if (mach < 1) { } else if (mach < 1) {
cd = 1 - 1.785 * (mach - 0.9); drag = 1 - 1.785 * (mach - 0.9);
} else { } else {
cd = 1.214 - 0.502 / pow2(mach) + 0.1095 / pow2(pow2(mach)); drag = 1.214 - 0.502 / pow2(mach) + 0.1095 / pow2(pow2(mach));
} }
} else if (crossSection == FinSet.CrossSection.SQUARE) { } else if (crossSection == FinSet.CrossSection.SQUARE) {
cd = stagnationCD; drag = stagnationCD;
} else { } else {
throw new UnsupportedOperationException("Unsupported fin profile: " + crossSection); throw new UnsupportedOperationException("Unsupported fin profile: " + crossSection);
} }
// Slanted leading edge // Slanted leading edge
cd *= pow2(cosGammaLead); drag *= pow2(cosGammaLead);
// Trailing edge drag // Trailing edge drag
if (crossSection == FinSet.CrossSection.SQUARE) { if (crossSection == FinSet.CrossSection.SQUARE) {
cd += baseCD; drag += baseCD;
} else if (crossSection == FinSet.CrossSection.ROUNDED) { } else if (crossSection == FinSet.CrossSection.ROUNDED) {
cd += baseCD / 2; drag += baseCD / 2;
} }
// Airfoil assumed to have zero base drag // Airfoil assumed to have zero base drag
// Scale to correct reference area // Scale to correct reference area
cd *= finCount * span * thickness / conditions.getRefArea(); drag *= finCount * span * thickness / conditions.getRefArea();
return cd; return drag;
} }
private static int calculateInterferenceFinCount(TubeFinSet component) { private static int calculateInterferenceFinCount(TubeFinSet component) {

4
core/src/net/sf/openrocket/simulation/RK4SimulationStepper.java
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@ -341,7 +341,7 @@ public class RK4SimulationStepper extends AbstractSimulationStepper {
// Linear forces in rocket coordinates // Linear forces in rocket coordinates
store.dragForce = store.forces.getCDaxial() * dynP * refArea; store.dragForce = store.forces.getCaxial() * dynP * refArea;
double fN = store.forces.getCN() * dynP * refArea; double fN = store.forces.getCN() * dynP * refArea;
double fSide = store.forces.getCside() * dynP * refArea; double fSide = store.forces.getCside() * dynP * refArea;
@ -646,7 +646,7 @@ public class RK4SimulationStepper extends AbstractSimulationStepper {
if (store.forces != null) { if (store.forces != null) {
data.setValue(FlightDataType.TYPE_DRAG_COEFF, store.forces.getCD()); data.setValue(FlightDataType.TYPE_DRAG_COEFF, store.forces.getCD());
data.setValue(FlightDataType.TYPE_AXIAL_DRAG_COEFF, store.forces.getCDaxial()); data.setValue(FlightDataType.TYPE_AXIAL_DRAG_COEFF, store.forces.getCaxial());
data.setValue(FlightDataType.TYPE_FRICTION_DRAG_COEFF, store.forces.getFrictionCD()); data.setValue(FlightDataType.TYPE_FRICTION_DRAG_COEFF, store.forces.getFrictionCD());
data.setValue(FlightDataType.TYPE_PRESSURE_DRAG_COEFF, store.forces.getPressureCD()); data.setValue(FlightDataType.TYPE_PRESSURE_DRAG_COEFF, store.forces.getPressureCD());
data.setValue(FlightDataType.TYPE_BASE_DRAG_COEFF, store.forces.getBaseCD()); data.setValue(FlightDataType.TYPE_BASE_DRAG_COEFF, store.forces.getBaseCD());

2
core/test/net/sf/openrocket/aerodynamics/SymmetricComponentCalcTest.java
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@ -136,7 +136,7 @@ public class SymmetricComponentCalcTest {
double m = i/20.0; double m = i/20.0;
String buf = "SymmetricComponentCalc produces bad Cd at index " + i + "(m=" + m +")"; String buf = "SymmetricComponentCalc produces bad Cd at index " + i + "(m=" + m +")";
conditions.setMach(m); conditions.setMach(m);
double testcd = calcObj.calculatePressureCD(conditions, 0.0, 0.0, warnings) * double testcd = calcObj.calculatePressureDragForce(conditions, 0.0, 0.0, warnings) *
conditions.getRefArea() / frontalArea; conditions.getRefArea() / frontalArea;
assertEquals(buf, cd[(int) Math.round(m*20)], testcd, EPSILON); assertEquals(buf, cd[(int) Math.round(m*20)], testcd, EPSILON);
} }