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adjusted cp to change based on a component's instance count

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This commit is contained in:
Daniel_M_Williams 2015-08-20 15:05:52 -04:00
parent 29ec764b61
commit 7882304839
1 changed files with 39 additions and 33 deletions
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72
core/src/net/sf/openrocket/aerodynamics/BarrowmanCalculator.java
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@ -32,14 +32,14 @@ public class BarrowmanCalculator extends AbstractAerodynamicCalculator {
private static final String BARROWMAN_PACKAGE = "net.sf.openrocket.aerodynamics.barrowman"; private static final String BARROWMAN_PACKAGE = "net.sf.openrocket.aerodynamics.barrowman";
private static final String BARROWMAN_SUFFIX = "Calc"; private static final String BARROWMAN_SUFFIX = "Calc";
private Map<RocketComponent, RocketComponentCalc> calcMap = null; private Map<RocketComponent, RocketComponentCalc> calcMap = null;
private double cacheDiameter = -1; private double cacheDiameter = -1;
private double cacheLength = -1; private double cacheLength = -1;
public BarrowmanCalculator() { public BarrowmanCalculator() {
} }
@ -63,7 +63,7 @@ public class BarrowmanCalculator extends AbstractAerodynamicCalculator {
} }
@Override @Override
public Map<RocketComponent, AerodynamicForces> getForceAnalysis(Configuration configuration, public Map<RocketComponent, AerodynamicForces> getForceAnalysis(Configuration configuration,
FlightConditions conditions, WarningSet warnings) { FlightConditions conditions, WarningSet warnings) {
@ -81,11 +81,11 @@ public class BarrowmanCalculator extends AbstractAerodynamicCalculator {
map.put(c, f); map.put(c, f);
} }
// Calculate non-axial force data // Calculate non-axial force data
AerodynamicForces total = calculateNonAxialForces(configuration, conditions, map, warnings); AerodynamicForces total = calculateNonAxialForces(configuration, conditions, map, warnings);
// Calculate friction data // Calculate friction data
total.setFrictionCD(calculateFrictionDrag(configuration, conditions, map, warnings)); total.setFrictionCD(calculateFrictionDrag(configuration, conditions, map, warnings));
total.setPressureCD(calculatePressureDrag(configuration, conditions, map, warnings)); total.setPressureCD(calculatePressureDrag(configuration, conditions, map, warnings));
@ -94,7 +94,7 @@ public class BarrowmanCalculator extends AbstractAerodynamicCalculator {
total.setComponent(configuration.getRocket()); total.setComponent(configuration.getRocket());
map.put(total.getComponent(), total); map.put(total.getComponent(), total);
for (RocketComponent c : map.keySet()) { for (RocketComponent c : map.keySet()) {
f = map.get(c); f = map.get(c);
if (Double.isNaN(f.getBaseCD()) && Double.isNaN(f.getPressureCD()) && if (Double.isNaN(f.getBaseCD()) && Double.isNaN(f.getPressureCD()) &&
@ -114,7 +114,7 @@ public class BarrowmanCalculator extends AbstractAerodynamicCalculator {
} }
@Override @Override
public AerodynamicForces getAerodynamicForces(Configuration configuration, public AerodynamicForces getAerodynamicForces(Configuration configuration,
FlightConditions conditions, WarningSet warnings) { FlightConditions conditions, WarningSet warnings) {
@ -140,13 +140,13 @@ public class BarrowmanCalculator extends AbstractAerodynamicCalculator {
total.setCm(total.getCm() - total.getPitchDampingMoment()); total.setCm(total.getCm() - total.getPitchDampingMoment());
total.setCyaw(total.getCyaw() - total.getYawDampingMoment()); total.setCyaw(total.getCyaw() - total.getYawDampingMoment());
return total; return total;
} }
/* /*
* Perform the actual CP calculation. * Perform the actual CP calculation.
*/ */
@ -168,7 +168,7 @@ public class BarrowmanCalculator extends AbstractAerodynamicCalculator {
if (conditions.getAOA() > 17.5 * Math.PI / 180) if (conditions.getAOA() > 17.5 * Math.PI / 180)
warnings.add(new Warning.LargeAOA(conditions.getAOA())); warnings.add(new Warning.LargeAOA(conditions.getAOA()));
if (calcMap == null) if (calcMap == null)
buildCalcMap(configuration); buildCalcMap(configuration);
@ -204,8 +204,14 @@ public class BarrowmanCalculator extends AbstractAerodynamicCalculator {
// Call calculation method // Call calculation method
forces.zero(); forces.zero();
calcMap.get(component).calculateNonaxialForces(conditions, forces, warnings); calcMap.get(component).calculateNonaxialForces(conditions, forces, warnings);
forces.setCP(component.toAbsolute(forces.getCP())[0]);
forces.setCm(forces.getCN() * forces.getCP().x / conditions.getRefLength()); int instanceCount = component.getLocation().length;
Coordinate x_cp_comp = forces.getCP();
Coordinate x_cp_weighted = x_cp_comp.setWeight(x_cp_comp.weight * instanceCount);
Coordinate x_cp_absolute = component.toAbsolute(x_cp_weighted)[0];
forces.setCP(x_cp_absolute);
double CN_instanced = forces.getCN() * instanceCount;
forces.setCm(CN_instanced * forces.getCP().x / conditions.getRefLength());
if (map != null) { if (map != null) {
AerodynamicForces f = map.get(component); AerodynamicForces f = map.get(component);
@ -236,11 +242,11 @@ public class BarrowmanCalculator extends AbstractAerodynamicCalculator {
} }
//////////////// DRAG CALCULATIONS //////////////// //////////////// DRAG CALCULATIONS ////////////////
private double calculateFrictionDrag(Configuration configuration, FlightConditions conditions, private double calculateFrictionDrag(Configuration 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;
@ -301,7 +307,7 @@ public class BarrowmanCalculator extends AbstractAerodynamicCalculator {
Cf *= c2; Cf *= c2;
} }
} else { } else {
// Assume fully turbulent. Roughness-limitation is checked later. // Assume fully turbulent. Roughness-limitation is checked later.
@ -344,8 +350,8 @@ public class BarrowmanCalculator extends AbstractAerodynamicCalculator {
roughnessCorrection = c2 * (mach - 0.9) / 0.2 + c1 * (1.1 - mach) / 0.2; roughnessCorrection = c2 * (mach - 0.9) / 0.2 + c1 * (1.1 - mach) / 0.2;
} }
/* /*
* Calculate the friction drag coefficient. * Calculate the friction drag coefficient.
* *
@ -353,7 +359,7 @@ public class BarrowmanCalculator extends AbstractAerodynamicCalculator {
* fineness ratio (calculated in the same iteration). The fins are corrected * fineness ratio (calculated in the same iteration). The fins are corrected
* for thickness as we go on. * for thickness as we go on.
*/ */
double finFriction = 0; double finFriction = 0;
double bodyFriction = 0; double bodyFriction = 0;
double maxR = 0, len = 0; double maxR = 0, len = 0;
@ -397,8 +403,8 @@ public class BarrowmanCalculator extends AbstractAerodynamicCalculator {
} }
// Calculate the friction drag: // Calculate the friction drag:
if (c instanceof SymmetricComponent) { if (c instanceof SymmetricComponent) {
@ -449,7 +455,7 @@ public class BarrowmanCalculator extends AbstractAerodynamicCalculator {
} }
private double calculatePressureDrag(Configuration configuration, FlightConditions conditions, private double calculatePressureDrag(Configuration configuration, FlightConditions conditions,
Map<RocketComponent, AerodynamicForces> map, WarningSet warnings) { Map<RocketComponent, AerodynamicForces> map, WarningSet warnings) {
@ -476,7 +482,7 @@ public class BarrowmanCalculator extends AbstractAerodynamicCalculator {
map.get(c).setPressureCD(cd); map.get(c).setPressureCD(cd);
} }
// Stagnation drag // Stagnation drag
if (c instanceof SymmetricComponent) { if (c instanceof SymmetricComponent) {
SymmetricComponent s = (SymmetricComponent) c; SymmetricComponent s = (SymmetricComponent) c;
@ -543,7 +549,7 @@ public class BarrowmanCalculator extends AbstractAerodynamicCalculator {
} }
public static double calculateStagnationCD(double m) { public static double calculateStagnationCD(double m) {
double pressure; double pressure;
if (m <= 1) { if (m <= 1) {
@ -564,7 +570,7 @@ public class BarrowmanCalculator extends AbstractAerodynamicCalculator {
} }
private static final double[] axialDragPoly1, axialDragPoly2; private static final double[] axialDragPoly1, axialDragPoly2;
static { static {
PolyInterpolator interpolator; PolyInterpolator interpolator;
@ -597,7 +603,7 @@ public class BarrowmanCalculator extends AbstractAerodynamicCalculator {
// double sinaoa = conditions.getSinAOA(); // double sinaoa = conditions.getSinAOA();
// return cd * (1 + Math.min(sinaoa, 0.25)); // return cd * (1 + Math.min(sinaoa, 0.25));
if (aoa > Math.PI / 2) if (aoa > Math.PI / 2)
aoa = Math.PI - aoa; aoa = Math.PI - aoa;
if (aoa < 17 * Math.PI / 180) if (aoa < 17 * Math.PI / 180)
@ -632,7 +638,7 @@ public class BarrowmanCalculator extends AbstractAerodynamicCalculator {
// TODO: MEDIUM: Are the rotation etc. being added correctly? sin/cos theta? // TODO: MEDIUM: Are the rotation etc. being added correctly? sin/cos theta?
private double getDampingMultiplier(Configuration configuration, FlightConditions conditions, private double getDampingMultiplier(Configuration configuration, FlightConditions conditions,
double cgx) { double cgx) {
if (cacheDiameter < 0) { if (cacheDiameter < 0) {
@ -664,9 +670,9 @@ public class BarrowmanCalculator extends AbstractAerodynamicCalculator {
FinSet f = (FinSet) c; FinSet f = (FinSet) c;
mul += 0.6 * Math.min(f.getFinCount(), 4) * f.getFinArea() * mul += 0.6 * Math.min(f.getFinCount(), 4) * f.getFinArea() *
MathUtil.pow3(Math.abs(f.toAbsolute(new Coordinate( MathUtil.pow3(Math.abs(f.toAbsolute(new Coordinate(
((FinSetCalc) calcMap.get(f)).getMidchordPos()))[0].x ((FinSetCalc) calcMap.get(f)).getMidchordPos()))[0].x
- cgx)) / - cgx)) /
(conditions.getRefArea() * conditions.getRefLength()); (conditions.getRefArea() * conditions.getRefLength());
} }
} }
@ -674,7 +680,7 @@ public class BarrowmanCalculator extends AbstractAerodynamicCalculator {
} }
//////// The calculator map //////// The calculator map
@Override @Override
@ -711,5 +717,5 @@ public class BarrowmanCalculator extends AbstractAerodynamicCalculator {
return 0; return 0;
} }
} }