bug fixes and rocket optimization

[debian/openrocket] / src / net / sf / openrocket / aerodynamics / barrowman / SymmetricComponentCalc.java

diff --git a/src/net/sf/openrocket/aerodynamics/barrowman/SymmetricComponentCalc.java b/src/net/sf/openrocket/aerodynamics/barrowman/SymmetricComponentCalc.java
index 446b97ea455639dbd2d7e7651dbc0b2bb2d324b6..42bce5474dbf68c302f02c03c60964930322d659 100644 (file)
--- a/src/net/sf/openrocket/aerodynamics/barrowman/SymmetricComponentCalc.java
+++ b/src/net/sf/openrocket/aerodynamics/barrowman/SymmetricComponentCalc.java
@@ -32,37 +32,45 @@ public class SymmetricComponentCalc extends RocketComponentCalc {
        
        public static final double BODY_LIFT_K = 1.1;
        
-       private final SymmetricComponent component;
-       
        private final double length;
-       private final double r1, r2;
+       private final double foreRadius, aftRadius;
        private final double fineness;
        private final Transition.Shape shape;
        private final double param;
-       private final double area;
+       private final double frontalArea;
+       private final double fullVolume;
+       private final double planformArea, planformCenter;
+       private final double sinphi;
        
        public SymmetricComponentCalc(RocketComponent c) {
                super(c);
                if (!(c instanceof SymmetricComponent)) {
                        throw new IllegalArgumentException("Illegal component type " + c);
                }
-               this.component = (SymmetricComponent) c;
+               SymmetricComponent component = (SymmetricComponent) c;
                
 
                length = component.getLength();
-               r1 = component.getForeRadius();
-               r2 = component.getAftRadius();
+               foreRadius = component.getForeRadius();
+               aftRadius = component.getAftRadius();
                
-               fineness = length / (2 * Math.abs(r2 - r1));
+               fineness = length / (2 * Math.abs(aftRadius - foreRadius));
+               fullVolume = component.getFullVolume();
+               planformArea = component.getComponentPlanformArea();
+               planformCenter = component.getComponentPlanformCenter();
                
                if (component instanceof BodyTube) {
                        shape = null;
                        param = 0;
-                       area = 0;
+                       frontalArea = 0;
+                       sinphi = 0;
                } else if (component instanceof Transition) {
                        shape = ((Transition) component).getType();
                        param = ((Transition) component).getShapeParameter();
-                       area = Math.abs(Math.PI * (r1 * r1 - r2 * r2));
+                       frontalArea = Math.abs(Math.PI * (foreRadius * foreRadius - aftRadius * aftRadius));
+                       
+                       double r = component.getRadius(0.99 * length);
+                       sinphi = (aftRadius - r) / MathUtil.hypot(aftRadius - r, 0.01 * length);
                } else {
                        throw new UnsupportedOperationException("Unknown component type " +
                                        component.getComponentName());
@@ -91,8 +99,8 @@ public class SymmetricComponentCalc extends RocketComponentCalc {
                
                // Pre-calculate and store the results
                if (Double.isNaN(cnaCache)) {
-                       final double r0 = component.getForeRadius();
-                       final double r1 = component.getAftRadius();
+                       final double r0 = foreRadius;
+                       final double r1 = aftRadius;
                        
                        if (MathUtil.equals(r0, r1)) {
                                isTube = true;
@@ -104,8 +112,8 @@ public class SymmetricComponentCalc extends RocketComponentCalc {
                                final double A1 = Math.PI * pow2(r1);
                                
                                cnaCache = 2 * (A1 - A0);
-                               System.out.println("cnaCache = " + cnaCache);
-                               cpCache = (component.getLength() * A1 - component.getFullVolume()) / (A1 - A0);
+                               //                              System.out.println("cnaCache = " + cnaCache);
+                               cpCache = (length * A1 - fullVolume) / (A1 - A0);
                        }
                }
                
@@ -143,8 +151,6 @@ public class SymmetricComponentCalc extends RocketComponentCalc {
         * Calculate the body lift effect according to Galejs.
         */
        protected Coordinate getLiftCP(FlightConditions conditions, WarningSet warnings) {
-               double area = component.getComponentPlanformArea();
-               double center = component.getComponentPlanformCenter();
                
                /*
                 * Without this extra multiplier the rocket may become unstable at apogee
@@ -159,7 +165,7 @@ public class SymmetricComponentCalc extends RocketComponentCalc {
                        mul = pow2(conditions.getMach() / 0.05);
                }
                
-               return new Coordinate(center, 0, 0, mul * BODY_LIFT_K * area / conditions.getRefArea() *
+               return new Coordinate(planformCenter, 0, 0, mul * BODY_LIFT_K * planformArea / conditions.getRefArea() *
                                conditions.getSinAOA() * conditions.getSincAOA()); // sin(aoa)^2 / aoa
        }
        
@@ -171,47 +177,36 @@ public class SymmetricComponentCalc extends RocketComponentCalc {
        public double calculatePressureDragForce(FlightConditions conditions,
                        double stagnationCD, double baseCD, WarningSet warnings) {
                
-               if (component instanceof BodyTube)
-                       return 0;
-               
-               if (!(component instanceof Transition)) {
-                       throw new BugException("Pressure calculation of unknown type: " +
-                                       component.getComponentName());
-               }
-               
                // Check for simple cases first
-               if (r1 == r2)
+               if (MathUtil.equals(foreRadius, aftRadius))
                        return 0;
                
                if (length < 0.001) {
-                       if (r1 < r2) {
-                               return stagnationCD * area / conditions.getRefArea();
+                       if (foreRadius < aftRadius) {
+                               return stagnationCD * frontalArea / conditions.getRefArea();
                        } else {
-                               return baseCD * area / conditions.getRefArea();
+                               return baseCD * frontalArea / conditions.getRefArea();
                        }
                }
                
 
                // Boattail drag computed directly from base drag
-               if (r2 < r1) {
+               if (aftRadius < foreRadius) {
                        if (fineness >= 3)
                                return 0;
-                       double cd = baseCD * area / conditions.getRefArea();
+                       double cd = baseCD * frontalArea / conditions.getRefArea();
                        if (fineness <= 1)
                                return cd;
                        return cd * (3 - fineness) / 2;
                }
                
 
-               assert (r1 < r2); // Tube and boattail have been checked already
-               
-
                // All nose cones and shoulders from pre-calculated and interpolating 
                if (interpolator == null) {
                        calculateNoseInterpolator();
                }
                
-               return interpolator.getValue(conditions.getMach()) * area / conditions.getRefArea();
+               return interpolator.getValue(conditions.getMach()) * frontalArea / conditions.getRefArea();
        }
        
        
@@ -287,9 +282,7 @@ public class SymmetricComponentCalc extends RocketComponentCalc {
                
                interpolator = new LinearInterpolator();
                
-               double r = component.getRadius(0.99 * length);
-               double sinphi = (r2 - r) / MathUtil.hypot(r2 - r, 0.01 * length);
-               
+
                /*
                 * Take into account nose cone shape.  Conical and ogive generate the interpolator
                 * directly.  Others store a interpolator for fineness ratio 3 into int1, or
@@ -355,8 +348,9 @@ public class SymmetricComponentCalc extends RocketComponentCalc {
                        throw new UnsupportedOperationException("Unknown transition shape: " + shape);
                }
                
-               assert (p >= 0);
-               assert (p <= 1.001);
+               if (p < 0 || p > 1.00001) {
+                       throw new BugException("Inconsistent parameter value p=" + p + " shape=" + shape);
+               }
                
 
                // Check for parameterized shape and interpolate if necessary