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Instead of iterating through all instances of components in calculating drag, just multiply the component's pressure, friction, and base drag by the number of instances.

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JoePfeiffer 2022-08-02 19:53:57 -06:00
parent e70b737fe1
commit 24b316655e
1 changed files with 95 additions and 98 deletions
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193
core/src/net/sf/openrocket/aerodynamics/BarrowmanCalculator.java
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@ -10,6 +10,7 @@ import org.slf4j.LoggerFactory;
import net.sf.openrocket.aerodynamics.barrowman.FinSetCalc; import net.sf.openrocket.aerodynamics.barrowman.FinSetCalc;
import net.sf.openrocket.aerodynamics.barrowman.RocketComponentCalc; import net.sf.openrocket.aerodynamics.barrowman.RocketComponentCalc;
import net.sf.openrocket.rocketcomponent.position.AxialMethod;
import net.sf.openrocket.rocketcomponent.ComponentAssembly; import net.sf.openrocket.rocketcomponent.ComponentAssembly;
import net.sf.openrocket.rocketcomponent.ExternalComponent; import net.sf.openrocket.rocketcomponent.ExternalComponent;
import net.sf.openrocket.rocketcomponent.ExternalComponent.Finish; import net.sf.openrocket.rocketcomponent.ExternalComponent.Finish;
@ -370,9 +371,10 @@ public class BarrowmanCalculator extends AbstractAerodynamicCalculator {
for(Map.Entry<RocketComponent, ArrayList<InstanceContext>> entry: imap.entrySet() ) { for(Map.Entry<RocketComponent, ArrayList<InstanceContext>> entry: imap.entrySet() ) {
final RocketComponent c = entry.getKey(); final RocketComponent c = entry.getKey();
if (!c.isAerodynamic()) if (!c.isAerodynamic()) {
continue; continue;
}
// Handle Overriden CD for Whole Rocket // Handle Overriden CD for Whole Rocket
if(c.isCDOverridden()) { if(c.isCDOverridden()) {
continue; continue;
@ -406,35 +408,30 @@ public class BarrowmanCalculator extends AbstractAerodynamicCalculator {
componentCf = Math.max(Cf, roughnessLimited[finish.ordinal()]); componentCf = Math.max(Cf, roughnessLimited[finish.ordinal()]);
} }
// iterate across component instances
double componentFrictionCDTotal = 0; // Total friction drag of the component
final ArrayList<InstanceContext> contextList = entry.getValue();
for(InstanceContext context: contextList ) {
double componentFrictionCD = calcMap.get(c).calculateFrictionCD(conditions, componentCf, warningSet);
if (c instanceof SymmetricComponent) { double componentFrictionCD = calcMap.get(c).calculateFrictionCD(conditions, componentCf, warningSet);
SymmetricComponent s = (SymmetricComponent) c;
bodyFrictionCD += componentFrictionCD;
final double componentMinX = context.getLocation().x; int instanceCount = entry.getValue().size();
minX = Math.min(minX, componentMinX); if (c instanceof SymmetricComponent) {
SymmetricComponent s = (SymmetricComponent) c;
final double componentMaxX = componentMinX + c.getLength(); bodyFrictionCD += instanceCount * componentFrictionCD;
maxX = Math.max(maxX, componentMaxX);
final double componentMinX = c.getAxialOffset(AxialMethod.ABSOLUTE);
minX = Math.min(minX, componentMinX);
final double componentMaxR = Math.max(s.getForeRadius(), s.getAftRadius()); final double componentMaxX = componentMinX + c.getLength();
maxR = Math.max(maxR, componentMaxR); maxX = Math.max(maxX, componentMaxX);
} else {
otherFrictionCD += componentFrictionCD;
}
componentFrictionCDTotal += componentFrictionCD; final double componentMaxR = Math.max(s.getForeRadius(), s.getAftRadius());
maxR = Math.max(maxR, componentMaxR);
} else {
otherFrictionCD += instanceCount * componentFrictionCD;
} }
if (map != null) { if (map != null) {
map.get(c).setFrictionCD(componentFrictionCDTotal); map.get(c).setFrictionCD(componentFrictionCD);
} }
} }
@ -450,7 +447,7 @@ public class BarrowmanCalculator extends AbstractAerodynamicCalculator {
} }
} }
} }
return otherFrictionCD + correction * bodyFrictionCD; return otherFrictionCD + correction * bodyFrictionCD;
} }
@ -593,59 +590,59 @@ public class BarrowmanCalculator extends AbstractAerodynamicCalculator {
*/ */
private double calculatePressureCD(FlightConfiguration configuration, FlightConditions conditions, private double calculatePressureCD(FlightConfiguration configuration, FlightConditions conditions,
Map<RocketComponent, AerodynamicForces> forceMap, WarningSet warningSet) { Map<RocketComponent, AerodynamicForces> forceMap, WarningSet warningSet) {
double stagnation, base, total; double total, stagnation, base;
if (calcMap == null) if (calcMap == null)
buildCalcMap(configuration); buildCalcMap(configuration);
stagnation = calculateStagnationCD(conditions.getMach()); stagnation = calculateStagnationCD(conditions.getMach());
base = calculateBaseCD(conditions.getMach()); base = calculateBaseCD(conditions.getMach());
total = 0; total = 0;
final InstanceMap imap = configuration.getActiveInstances(); final InstanceMap imap = configuration.getActiveInstances();
for(Map.Entry<RocketComponent, ArrayList<InstanceContext>> entry: imap.entrySet() ) { for(Map.Entry<RocketComponent, ArrayList<InstanceContext>> entry: imap.entrySet() ) {
final RocketComponent c = entry.getKey(); final RocketComponent c = entry.getKey();
if (!c.isAerodynamic()) if (!c.isAerodynamic()) {
continue; continue;
// iterate across component instances
double pressureCDTotal = 0; // Total pressure drag for this component
final ArrayList<InstanceContext> contextList = entry.getValue();
for(InstanceContext context: contextList ) {
// Pressure drag
double pressureCD = calcMap.get(c).calculatePressureCD(conditions, stagnation, base,
warningSet);
pressureCDTotal += pressureCD;
// Total pressure drag of the rocket
total += pressureCD;
if(c.isCDOverridden())
continue;
// Stagnation drag
if (c instanceof SymmetricComponent) {
SymmetricComponent s = (SymmetricComponent) c;
double radius = 0;
final SymmetricComponent prevComponent = s.getPreviousSymmetricComponent();
if (prevComponent != null && configuration.isComponentActive(prevComponent))
radius = prevComponent.getAftRadius();
if (radius < s.getForeRadius()) {
double area = Math.PI * (pow2(s.getForeRadius()) - pow2(radius));
pressureCD = stagnation * area / conditions.getRefArea();
pressureCDTotal += pressureCD;
total += pressureCD;
}
}
} }
if(c.isCDOverridden()) {
continue;
}
int instanceCount = entry.getValue().size();
// Pressure drag of this component
double cd = calcMap.get(c).calculatePressureCD(conditions, stagnation, base,
warningSet);
if (forceMap != null) { if (forceMap != null) {
forceMap.get(c).setPressureCD(pressureCDTotal); forceMap.get(c).setPressureCD(cd);
}
total += cd * instanceCount;
// Stagnation drag caused by difference in radius between this component
// and previous component (increasing radii. Decreasing radii handled in
// base drag calculation
if (c instanceof SymmetricComponent) {
SymmetricComponent s = (SymmetricComponent) c;
double radius = 0;
final SymmetricComponent prevComponent = s.getPreviousSymmetricComponent();
if (prevComponent != null && configuration.isComponentActive(prevComponent))
radius = prevComponent.getAftRadius();
if (radius < s.getForeRadius()) {
double area = Math.PI * (pow2(s.getForeRadius()) - pow2(radius));
cd = stagnation * area / conditions.getRefArea();
total += instanceCount * cd;
if (forceMap != null) {
forceMap.get(c).setPressureCD(forceMap.get(c).getPressureCD() + cd);
}
}
} }
} }
@ -677,47 +674,46 @@ public class BarrowmanCalculator extends AbstractAerodynamicCalculator {
for(Map.Entry<RocketComponent, ArrayList<InstanceContext>> entry: imap.entrySet() ) { for(Map.Entry<RocketComponent, ArrayList<InstanceContext>> entry: imap.entrySet() ) {
final RocketComponent c = entry.getKey(); final RocketComponent c = entry.getKey();
if (!(c instanceof SymmetricComponent)) if (!(c instanceof SymmetricComponent)) {
continue; continue;
}
SymmetricComponent s = (SymmetricComponent) c; SymmetricComponent s = (SymmetricComponent) c;
int instanceCount = entry.getValue().size();
// iterate across component instances if(c.isCDOverridden()) {
final ArrayList<InstanceContext> contextList = entry.getValue(); total += instanceCount * c.getOverrideCD();
for(InstanceContext context: contextList ) { continue;
if(c.isCDOverridden()) { }
total += c.getOverrideCD();
continue;
}
// if aft radius of previous component is greater than my forward radius, set // if aft radius of previous component is greater than my forward radius, set
// its aft CD // its aft CD
double radius = 0; double radius = 0;
final SymmetricComponent prevComponent = s.getPreviousSymmetricComponent(); final SymmetricComponent prevComponent = s.getPreviousSymmetricComponent();
if (prevComponent != null && configuration.isComponentActive(prevComponent)) { if (prevComponent != null && configuration.isComponentActive(prevComponent)) {
radius = prevComponent.getAftRadius(); radius = prevComponent.getAftRadius();
}
if (radius > s.getForeRadius()) {
double area = Math.PI * (pow2(radius) - pow2(s.getForeRadius()));
double cd = base * area / conditions.getRefArea();
total += instanceCount * cd;
if ((map != null) && (prevComponent != null)) {
map.get(prevComponent).setBaseCD(cd);
} }
}
if (radius > s.getForeRadius()) { // if I'm the last component, set my base CD
double area = Math.PI * (pow2(radius) - pow2(s.getForeRadius())); // note: the iterator *should* serve up the next component.... buuuut ....
double baseCD = base * area / conditions.getRefArea(); // this code has is tested, and there's no compelling reason to change.
total += baseCD; final SymmetricComponent n = s.getNextSymmetricComponent();
if ((map != null) && (prevComponent != null)) { if ((n == null) || !configuration.isStageActive(n.getStageNumber())) {
map.get(prevComponent).setBaseCD(baseCD); double area = Math.PI * pow2(s.getAftRadius());
} double cd = base * area / conditions.getRefArea();
} total += instanceCount * cd;
if (map != null) {
// if I'm the last component, set my base CD map.get(s).setBaseCD(cd);
// note: the iterator *should* serve up the next component.... buuuut ....
// this code has is tested, and there's no compelling reason to change.
final SymmetricComponent n = s.getNextSymmetricComponent();
if ((n == null) || !configuration.isStageActive(n.getStageNumber())) {
double area = Math.PI * pow2(s.getAftRadius());
double baseCD = base * area / conditions.getRefArea();
total += baseCD;
if (map != null) {
map.get(s).setBaseCD(baseCD);
}
} }
} }
} }
@ -889,8 +885,9 @@ public class BarrowmanCalculator extends AbstractAerodynamicCalculator {
calcMap = new HashMap<>(); calcMap = new HashMap<>();
for (RocketComponent comp: configuration.getAllComponents()) { for (RocketComponent comp: configuration.getAllComponents()) {
if (!comp.isAerodynamic()) if (!comp.isAerodynamic()) {
continue; continue;
}
RocketComponentCalc calcObj = (RocketComponentCalc) Reflection.construct(BARROWMAN_PACKAGE, comp, BARROWMAN_SUFFIX, comp); RocketComponentCalc calcObj = (RocketComponentCalc) Reflection.construct(BARROWMAN_PACKAGE, comp, BARROWMAN_SUFFIX, comp);