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Merge pull request #2214 from SiboVG/issue-2209

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[#2209] Average segment centroids
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Sibo Van Gool 2023-05-15 19:24:01 +02:00 committed by GitHub
commit b8895a1ea0
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2 changed files with 63 additions and 9 deletions
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19
core/src/net/sf/openrocket/rocketcomponent/FinSet.java
View File

@ -544,7 +544,7 @@ public abstract class FinSet extends ExternalComponent implements AxialPositiona
return centerOfMass;
}
private static Coordinate calculateFilletCrossSection(final double filletRadius, final double bodyRadius){
private static Coordinate calculateFilletCrossSection(final double filletRadius, final double bodyRadius) {
final double hypotenuse = filletRadius + bodyRadius;
final double innerArcAngle = Math.asin(filletRadius / hypotenuse);
final double outerArcAngle = Math.acos(filletRadius / hypotenuse);
@ -554,17 +554,17 @@ public abstract class FinSet extends ExternalComponent implements AxialPositiona
- outerArcAngle * filletRadius * filletRadius / 2
- innerArcAngle * bodyRadius * bodyRadius / 2);
if(Double.isNaN(crossSectionArea)) {
if (Double.isNaN(crossSectionArea)) {
crossSectionArea = 0.;
}else {
} else {
// each fin has a fillet on each side
crossSectionArea *= 2;
}
// heuristic, relTo the body center
double yCentroid = bodyRadius + filletRadius /5;
double yCentroid = bodyRadius + filletRadius / 5;
return new Coordinate(0,yCentroid,0,crossSectionArea);
return new Coordinate(0, yCentroid, 0, crossSectionArea);
}
/*
@ -581,7 +581,8 @@ public abstract class FinSet extends ExternalComponent implements AxialPositiona
* 5. Return twice that since there is a fillet on each side of the fin.
*/
protected Coordinate calculateFilletVolumeCentroid() {
if((null == this.parent) || (!SymmetricComponent.class.isAssignableFrom(this.parent.getClass()))){
if ((this.filletRadius == 0) || (this.parent == null) ||
(!SymmetricComponent.class.isAssignableFrom(this.parent.getClass()))) {
return Coordinate.ZERO;
}
Coordinate[] mountPoints = this.getRootPoints();
@ -594,7 +595,7 @@ public abstract class FinSet extends ExternalComponent implements AxialPositiona
final Coordinate finLead = getFinFront();
final double xFinEnd = finLead.x + getLength();
final Coordinate[] rootPoints = getMountPoints( finLead.x, xFinEnd, -finLead.x, -finLead.y);
if (0 == rootPoints.length) {
if (rootPoints.length == 0) {
return Coordinate.ZERO;
}
@ -616,7 +617,7 @@ public abstract class FinSet extends ExternalComponent implements AxialPositiona
final Coordinate segmentCentroid = segmentCrossSection.setWeight(segmentVolume);
filletVolumeCentroid = filletVolumeCentroid.add(segmentCentroid);
filletVolumeCentroid = filletVolumeCentroid.average(segmentCentroid);
prev = cur;
}
@ -624,7 +625,7 @@ public abstract class FinSet extends ExternalComponent implements AxialPositiona
if (finCount == 1) {
Transformation rotation = Transformation.rotate_x( getAngleOffset());
return rotation.transform(filletVolumeCentroid);
}else{
} else{
return filletVolumeCentroid.setY(0.);
}
}

53
core/test/net/sf/openrocket/rocketcomponent/TrapezoidFinSetTest.java
View File

@ -52,6 +52,32 @@ public class TrapezoidFinSetTest extends BaseTestCase {
return rkt;
}
private Rocket createFreeformFinOnTransition() {
final Rocket rkt = new Rocket();
final AxialStage stg = new AxialStage();
rkt.addChild(stg);
Transition transition = new Transition();
transition.setLength(0.2);
transition.setForeRadius(0.1);
transition.setAftRadius(0.3);
transition.setShapeType(Transition.Shape.OGIVE);
stg.addChild(transition);
FreeformFinSet fins = new FreeformFinSet();
fins.setFinCount(1);
fins.setAxialOffset(AxialMethod.MIDDLE, 0.0);
fins.setMaterial(Material.newMaterial(Material.Type.BULK, "Fin-Test-Material", 1.0, true));
fins.setThickness(0.005); // == 5 mm
transition.addChild(fins);
fins.setTabLength(0.00);
fins.setFilletRadius(0.0);
rkt.enableEvents();
return rkt;
}
@Test
public void testMultiplicity() {
final TrapezoidFinSet trapFins = new TrapezoidFinSet();
@ -187,6 +213,33 @@ public class TrapezoidFinSetTest extends BaseTestCase {
}
}
@Test
public void testFilletCalculationsOnTransition() {
final Rocket rkt = createFreeformFinOnTransition();
Transition transition = (Transition) rkt.getChild(0).getChild(0);
FinSet fins = (FinSet) rkt.getChild(0).getChild(0).getChild(0);
fins.setFilletRadius(0.005);
fins.setFilletMaterial(Material.newMaterial(Material.Type.BULK, "Fillet-Test-Material", 1.0, true));
// used for fillet and edge calculations:
//
// [1] +--+ [2]
// / \
// / \
// [0] +--------+ [3]
//
assertEquals(0.05, fins.getLength(), EPSILON);
assertEquals("Transition fore radius doesn't match: ", 0.1, transition.getForeRadius(), EPSILON);
assertEquals("Transition aft radius doesn't match: ", 0.3, transition.getAftRadius(), EPSILON);
final Coordinate actVolume = fins.calculateFilletVolumeCentroid();
assertEquals("Fin volume doesn't match: ", 5.973e-07, actVolume.weight, EPSILON);
assertEquals("Fin mass center.x doesn't match: ", 0.024393025, actVolume.x, EPSILON);
assertEquals("Fin mass center.y doesn't match: ", 0.190479957, actVolume.y, EPSILON);
}
@Test
public void testTrapezoidCGComputation() {
{