diff --git a/core/resources/l10n/messages.properties b/core/resources/l10n/messages.properties
index 82be3c83b..df4f1f662 100644
--- a/core/resources/l10n/messages.properties
+++ b/core/resources/l10n/messages.properties
@@ -1888,6 +1888,7 @@ Warning.PODSET_FORWARD = In-line podset forward of parent airframe component
Warning.PODSET_OVERLAP = In-line podset overlaps parent airframe component
Warning.THICK_FIN = Thick fins may not simulate accurately.
Warning.JAGGED_EDGED_FIN = Jagged-edged fin predictions may be inaccurate.
+Warning.ZERO_AREA_FIN = Fins with zero area will not affect aerodynamics
Warning.LISTENERS_AFFECTED = Listeners modified the flight simulation
Warning.RECOVERY_DEPLOYMENT_WHILE_BURNING = Recovery device opened while motor still burning.
Warning.FILE_INVALID_PARAMETER = Invalid parameter encountered, ignoring.
diff --git a/core/src/net/sf/openrocket/aerodynamics/Warning.java b/core/src/net/sf/openrocket/aerodynamics/Warning.java
index 3c17c1e17..71946ca5b 100644
--- a/core/src/net/sf/openrocket/aerodynamics/Warning.java
+++ b/core/src/net/sf/openrocket/aerodynamics/Warning.java
@@ -382,6 +382,10 @@ public abstract class Warning {
////Jagged-edged fin predictions may be inaccurate.
public static final Warning JAGGED_EDGED_FIN = new Other(trans.get("Warning.JAGGED_EDGED_FIN"));
+ /** A Warning that the fins have a zero area. */
+ ////Fins with no area will not affect aerodynamics
+ public static final Warning ZERO_AREA_FIN = new Other(trans.get("Warning.ZERO_AREA_FIN"));
+
/** A Warning that simulation listeners have affected the simulation */
////Listeners modified the flight simulation
public static final Warning LISTENERS_AFFECTED = new Other(trans.get("Warning.LISTENERS_AFFECTED"));
diff --git a/core/src/net/sf/openrocket/aerodynamics/barrowman/FinSetCalc.java b/core/src/net/sf/openrocket/aerodynamics/barrowman/FinSetCalc.java
index 53746d2e6..326c73a0d 100644
--- a/core/src/net/sf/openrocket/aerodynamics/barrowman/FinSetCalc.java
+++ b/core/src/net/sf/openrocket/aerodynamics/barrowman/FinSetCalc.java
@@ -84,7 +84,9 @@ public class FinSetCalc extends RocketComponentCalc {
public void calculateNonaxialForces(FlightConditions conditions, Transformation transform,
AerodynamicForces forces, WarningSet warnings) {
- if (span < 0.001) {
+ warnings.addAll(geometryWarnings);
+
+ if (finArea < MathUtil.EPSILON) {
forces.setCm(0);
forces.setCN(0);
forces.setCNa(0);
@@ -96,12 +98,6 @@ public class FinSetCalc extends RocketComponentCalc {
forces.setCyaw(0);
return;
}
-
- if ((bodyRadius > 0) && (thickness > bodyRadius / 2)){
- // Add warnings (radius/2 == diameter/4)
- warnings.add(Warning.THICK_FIN);
- }
- warnings.addAll(geometryWarnings);
//////// Calculate CNa. /////////
@@ -241,18 +237,27 @@ public class FinSetCalc extends RocketComponentCalc {
Coordinate[] points = component.getFinPoints();
- // Check for jagged edges
+ // Check geometry
geometryWarnings.clear();
boolean down = false;
for (int i = 1; i < points.length; i++) {
if ((points[i].y > points[i - 1].y + 0.001) && down) {
- geometryWarnings.add(Warning.JAGGED_EDGED_FIN);
+ geometryWarnings.add(Warning.JAGGED_EDGED_FIN, component.toString());
break;
}
if (points[i].y < points[i - 1].y - 0.001) {
down = true;
}
}
+
+ if (finArea < MathUtil.EPSILON) {
+ geometryWarnings.add(Warning.ZERO_AREA_FIN, component.toString());
+ }
+
+ if ((bodyRadius > 0) && (thickness > bodyRadius / 2)){
+ // Add warnings (radius/2 == diameter/4)
+ geometryWarnings.add(Warning.THICK_FIN, component.toString());
+ }
// Calculate the chord lead and trail positions and length
@@ -365,7 +370,6 @@ public class FinSetCalc extends RocketComponentCalc {
macLead *= dy;
area *= dy;
rollSum *= dy;
-
macLength /= area;
macSpan /= area;
macLead /= area;
@@ -614,6 +618,11 @@ public class FinSetCalc extends RocketComponentCalc {
@Override
public double calculateFrictionCD(FlightConditions conditions, double componentCf, WarningSet warnings) {
+ // a fin with 0 area contributes no drag
+ if (finArea < MathUtil.EPSILON) {
+ return 0.0;
+ }
+
double cd = componentCf * (1 + 2 * thickness / macLength) * 2 * finArea / conditions.getRefArea();
return cd;
}
@@ -622,6 +631,11 @@ public class FinSetCalc extends RocketComponentCalc {
public double calculatePressureCD(FlightConditions conditions,
double stagnationCD, double baseCD, WarningSet warnings) {
+ // a fin with 0 area contributes no drag
+ if (finArea < MathUtil.EPSILON) {
+ return 0.0;
+ }
+
double mach = conditions.getMach();
double cd = 0;