X-Git-Url: https://git.gag.com/?a=blobdiff_plain;f=core%2Fsrc%2Fnet%2Fsf%2Fopenrocket%2Fsimulation%2Flisteners%2Fexample%2FDampingMoment.java;fp=core%2Fsrc%2Fnet%2Fsf%2Fopenrocket%2Fsimulation%2Flisteners%2Fexample%2FDampingMoment.java;h=b9d2e463af330f0fa1b264ea3e8c025cafd801ea;hb=c482637086621542ea78ba8818f315dce0a11dc2;hp=0000000000000000000000000000000000000000;hpb=c322e9329373aa7f0b071663874327da7e650082;p=debian%2Fopenrocket

diff --git a/core/src/net/sf/openrocket/simulation/listeners/example/DampingMoment.java b/core/src/net/sf/openrocket/simulation/listeners/example/DampingMoment.java
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index 00000000..b9d2e463
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+++ b/core/src/net/sf/openrocket/simulation/listeners/example/DampingMoment.java
@@ -0,0 +1,129 @@
+package net.sf.openrocket.simulation.listeners.example;
+
+import java.util.List;
+import java.util.Map;
+
+import net.sf.openrocket.aerodynamics.AerodynamicCalculator;
+import net.sf.openrocket.aerodynamics.AerodynamicForces;
+import net.sf.openrocket.aerodynamics.FlightConditions;
+import net.sf.openrocket.motor.MotorId;
+import net.sf.openrocket.motor.MotorInstance;
+import net.sf.openrocket.motor.MotorInstanceConfiguration;
+import net.sf.openrocket.rocketcomponent.MotorMount;
+import net.sf.openrocket.rocketcomponent.RocketComponent;
+import net.sf.openrocket.simulation.FlightDataBranch;
+import net.sf.openrocket.simulation.FlightDataType;
+import net.sf.openrocket.simulation.SimulationStatus;
+import net.sf.openrocket.simulation.exception.SimulationException;
+import net.sf.openrocket.simulation.listeners.AbstractSimulationListener;
+import net.sf.openrocket.unit.UnitGroup;
+import net.sf.openrocket.util.ArrayList;
+import net.sf.openrocket.util.Coordinate;
+import net.sf.openrocket.util.PolyInterpolator;
+
+public class DampingMoment extends AbstractSimulationListener {
+	
+	private static final FlightDataType type = FlightDataType.getType("Damping moment coefficient", "Cdm", UnitGroup.UNITS_COEFFICIENT);
+	private static final FlightDataType[] typeList = {type};
+	
+	public String getName(){
+		return "Damping moment listener";
+	}
+	
+	/**
+	 * Return a list of any flight data types this listener creates.
+	 */
+	public FlightDataType[] getFlightDataTypes(){
+		return typeList;
+	}
+	
+	@Override
+	public FlightConditions postFlightConditions(SimulationStatus status, FlightConditions flightConditions) throws SimulationException {
+		
+		// Save it as a flightdatatype
+		
+		//status.getFlightData().setValue(type, aerodynamicPart + propulsivePart);
+		status.getFlightData().setValue(type, calculate(status, flightConditions));
+
+		return flightConditions;
+	}
+	
+	private double calculate(SimulationStatus status, FlightConditions flightConditions){
+		
+		// Work out the propulsive/jet damping part of the moment.
+		
+		// dm/dt = (thrust - ma)/v
+		FlightDataBranch data = status.getFlightData();
+		
+		List<Double> mpAll = data.get(FlightDataType.TYPE_PROPELLANT_MASS);
+		List<Double> time = data.get(FlightDataType.TYPE_TIME);
+		if (mpAll == null || time == null){
+			return Double.NaN;
+		}
+		
+		int len = mpAll.size();
+		
+		// This isn't as accurate as I would like
+		double mdot=Double.NaN;
+		if (len > 2){
+			// Using polynomial interpolator for derivative. Doesn't help much
+			//double[] x = { time.get(len-5), time.get(len-4), time.get(len-3), time.get(len-2), time.get(len-1) };
+			//double[] y = { mpAll.get(len-5), mpAll.get(len-4), mpAll.get(len-3), mpAll.get(len-2), mpAll.get(len-1) };
+			//PolyInterpolator interp = new PolyInterpolator(x);
+			//double[] coeff = interp.interpolator(y);
+			//double dt = .01;
+			//mdot = (interp.eval(x[4], coeff) - interp.eval(x[4]-dt, coeff))/dt; 
+						
+			mdot = (mpAll.get(len-1) - mpAll.get(len-2)) / (time.get(len-1) - time.get(len-2));
+		}
+		
+		double cg = data.getLast(FlightDataType.TYPE_CG_LOCATION);
+		
+		// find the maximum distance from nose to nozzle. 
+		double nozzleDistance = 0;
+		for (MotorId id: status.getMotorConfiguration().getMotorIDs()){
+			MotorInstanceConfiguration config = status.getMotorConfiguration();
+			Coordinate position = config.getMotorPosition(id);
+			
+			double x = position.x + config.getMotorInstance(id).getParentMotor().getLength();
+			if (x > nozzleDistance){
+				nozzleDistance = x;
+			}			
+		}
+		
+		// now can get the propulsive part
+		double propulsivePart = mdot * Math.pow(nozzleDistance - cg, 2);
+		
+		// Work out the aerodynamic part of the moment.
+		double aerodynamicPart = 0;
+		
+		AerodynamicCalculator aerocalc = status.getSimulationConditions().getAerodynamicCalculator();
+		
+		// Must go through each component ...
+		Map<RocketComponent, AerodynamicForces> forces = aerocalc.getForceAnalysis(status.getConfiguration(), flightConditions, null);
+		for (Map.Entry<RocketComponent, AerodynamicForces> entry : forces.entrySet()){
+			
+			RocketComponent comp = entry.getKey();
+			
+			if (!comp.isAerodynamic()) continue;
+			
+			//System.out.println(comp.toString());
+			
+			double CNa = entry.getValue().getCNa(); //?
+			double Cp = entry.getValue().getCP().length();
+			double z = comp.getPositionValue(); //?
+			
+			aerodynamicPart += CNa*Math.pow(z-Cp, 2);
+		}
+		
+		double v = flightConditions.getVelocity();
+		double rho = flightConditions.getAtmosphericConditions().getDensity();
+		double ar = flightConditions.getRefArea();
+		
+		aerodynamicPart = aerodynamicPart * .5 * rho * v * ar;
+		
+		return aerodynamicPart + propulsivePart;
+	
+	}
+	
+}