Merge branch 'openrocket-unstable2' into gradle
This commit is contained in:
thzero
commit
a5f94a0b45
@ -0,0 +1,184 @@
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package net.sf.openrocket.simulation;
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import org.slf4j.Logger;
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import org.slf4j.LoggerFactory;
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import net.sf.openrocket.models.atmosphere.AtmosphericConditions;
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import net.sf.openrocket.rocketcomponent.InstanceMap;
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import net.sf.openrocket.rocketcomponent.RecoveryDevice;
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import net.sf.openrocket.simulation.exception.SimulationException;
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import net.sf.openrocket.util.Coordinate;
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import net.sf.openrocket.util.GeodeticComputationStrategy;
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import net.sf.openrocket.util.MathUtil;
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import net.sf.openrocket.util.WorldCoordinate;
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public abstract class AbstractEulerStepper extends AbstractSimulationStepper {
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private static final Logger log = LoggerFactory.getLogger(AbstractEulerStepper.class);
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private static final double RECOVERY_TIME_STEP = 0.5;
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protected double cd;
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@Override
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public SimulationStatus initialize(SimulationStatus status) {
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this.cd = computeCD(status);
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return status;
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}
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private double getCD() {
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return cd;
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}
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protected abstract double computeCD(SimulationStatus status);
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@Override
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public void step(SimulationStatus status, double maxTimeStep) throws SimulationException {
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// Get the atmospheric conditions
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AtmosphericConditions atmosphere = modelAtmosphericConditions(status);
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//// Local wind speed and direction
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Coordinate windSpeed = modelWindVelocity(status);
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Coordinate airSpeed = status.getRocketVelocity().add(windSpeed);
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// Compute drag force
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double mach = airSpeed.length() / atmosphere.getMachSpeed();
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double dynP = (0.5 * atmosphere.getDensity() * airSpeed.length2());
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double dragForce = getCD() * dynP * status.getConfiguration().getReferenceArea();
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// n.b. this is constant, and could be calculated once at the beginning of this simulation branch...
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double rocketMass = calculateStructureMass(status).getMass();
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double motorMass = calculateMotorMass(status).getMass();
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double mass = rocketMass + motorMass;
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// Compute drag acceleration
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Coordinate linearAcceleration;
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if (airSpeed.length() > 0.001) {
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linearAcceleration = airSpeed.normalize().multiply(-dragForce / mass);
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} else {
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linearAcceleration = Coordinate.NUL;
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}
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// Add effect of gravity
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double gravity = modelGravity(status);
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linearAcceleration = linearAcceleration.sub(0, 0, gravity);
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// Add coriolis acceleration
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Coordinate coriolisAcceleration = status.getSimulationConditions().getGeodeticComputation().getCoriolisAcceleration(
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status.getRocketWorldPosition(), status.getRocketVelocity());
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linearAcceleration = linearAcceleration.add(coriolisAcceleration);
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// Select tentative time step
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double timeStep = RECOVERY_TIME_STEP;
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// adjust based on change in acceleration (ie jerk)
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final double jerk = Math.abs(linearAcceleration.sub(status.getRocketAcceleration()).multiply(1.0/status.getPreviousTimeStep()).length());
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if (jerk > MathUtil.EPSILON) {
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timeStep = Math.min(timeStep, 1.0/jerk);
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}
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// but don't let it get *too* small
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timeStep = Math.max(timeStep, MIN_TIME_STEP);
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log.trace("timeStep is " + timeStep);
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// Perform Euler integration
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Coordinate newPosition = status.getRocketPosition().add(status.getRocketVelocity().multiply(timeStep)).
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add(linearAcceleration.multiply(MathUtil.pow2(timeStep) / 2));
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// If I've hit the ground, recalculate time step and position
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if (newPosition.z < 0) {
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final double a = linearAcceleration.z;
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final double v = status.getRocketVelocity().z;
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final double z0 = status.getRocketPosition().z;
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// The new timestep is the solution of
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// 1/2 at^2 + vt + z0 = 0
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timeStep = (-v - Math.sqrt(v*v - 2*a*z0))/a;
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log.trace("ground hit changes timeStep to " + timeStep);
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newPosition = status.getRocketPosition().add(status.getRocketVelocity().multiply(timeStep)).
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add(linearAcceleration.multiply(MathUtil.pow2(timeStep) / 2));
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// avoid rounding error in new altitude
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newPosition = newPosition.setZ(0);
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}
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status.setSimulationTime(status.getSimulationTime() + timeStep);
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status.setPreviousTimeStep(timeStep);
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status.setRocketPosition(newPosition);
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status.setRocketVelocity(status.getRocketVelocity().add(linearAcceleration.multiply(timeStep)));
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status.setRocketAcceleration(linearAcceleration);
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// Update the world coordinate
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WorldCoordinate w = status.getSimulationConditions().getLaunchSite();
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w = status.getSimulationConditions().getGeodeticComputation().addCoordinate(w, status.getRocketPosition());
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status.setRocketWorldPosition(w);
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// Store data
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FlightDataBranch data = status.getFlightData();
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boolean extra = status.getSimulationConditions().isCalculateExtras();
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data.addPoint();
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data.setValue(FlightDataType.TYPE_TIME, status.getSimulationTime());
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data.setValue(FlightDataType.TYPE_ALTITUDE, status.getRocketPosition().z);
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data.setValue(FlightDataType.TYPE_POSITION_X, status.getRocketPosition().x);
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data.setValue(FlightDataType.TYPE_POSITION_Y, status.getRocketPosition().y);
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airSpeed = status.getRocketVelocity().add(windSpeed);
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if (extra) {
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data.setValue(FlightDataType.TYPE_POSITION_XY,
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MathUtil.hypot(status.getRocketPosition().x, status.getRocketPosition().y));
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data.setValue(FlightDataType.TYPE_POSITION_DIRECTION,
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Math.atan2(status.getRocketPosition().y, status.getRocketPosition().x));
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data.setValue(FlightDataType.TYPE_VELOCITY_XY,
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MathUtil.hypot(status.getRocketVelocity().x, status.getRocketVelocity().y));
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data.setValue(FlightDataType.TYPE_ACCELERATION_XY,
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MathUtil.hypot(linearAcceleration.x, linearAcceleration.y));
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data.setValue(FlightDataType.TYPE_ACCELERATION_TOTAL, linearAcceleration.length());
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double Re = airSpeed.length() *
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status.getConfiguration().getLengthAerodynamic() /
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atmosphere.getKinematicViscosity();
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data.setValue(FlightDataType.TYPE_REYNOLDS_NUMBER, Re);
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}
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data.setValue(FlightDataType.TYPE_LATITUDE, status.getRocketWorldPosition().getLatitudeRad());
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data.setValue(FlightDataType.TYPE_LONGITUDE, status.getRocketWorldPosition().getLongitudeRad());
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data.setValue(FlightDataType.TYPE_GRAVITY, gravity);
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if (status.getSimulationConditions().getGeodeticComputation() != GeodeticComputationStrategy.FLAT) {
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data.setValue(FlightDataType.TYPE_CORIOLIS_ACCELERATION, coriolisAcceleration.length());
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}
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data.setValue(FlightDataType.TYPE_VELOCITY_Z, status.getRocketVelocity().z);
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data.setValue(FlightDataType.TYPE_ACCELERATION_Z, linearAcceleration.z);
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data.setValue(FlightDataType.TYPE_VELOCITY_TOTAL, airSpeed.length());
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data.setValue(FlightDataType.TYPE_MACH_NUMBER, mach);
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data.setValue(FlightDataType.TYPE_MASS, mass);
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data.setValue(FlightDataType.TYPE_MOTOR_MASS, motorMass);
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data.setValue(FlightDataType.TYPE_THRUST_FORCE, 0);
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data.setValue(FlightDataType.TYPE_DRAG_FORCE, dragForce);
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data.setValue(FlightDataType.TYPE_WIND_VELOCITY, windSpeed.length());
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data.setValue(FlightDataType.TYPE_AIR_TEMPERATURE, atmosphere.getTemperature());
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data.setValue(FlightDataType.TYPE_AIR_PRESSURE, atmosphere.getPressure());
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data.setValue(FlightDataType.TYPE_SPEED_OF_SOUND, atmosphere.getMachSpeed());
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data.setValue(FlightDataType.TYPE_TIME_STEP, timeStep);
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data.setValue(FlightDataType.TYPE_COMPUTATION_TIME,
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(System.nanoTime() - status.getSimulationStartWallTime()) / 1000000000.0);
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log.trace("time " + data.getLast(FlightDataType.TYPE_TIME) + ", altitude " + data.getLast(FlightDataType.TYPE_ALTITUDE) + ", velocity " + data.getLast(FlightDataType.TYPE_VELOCITY_Z));
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}
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}
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@ -1,185 +1,18 @@
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package net.sf.openrocket.simulation;
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import net.sf.openrocket.models.atmosphere.AtmosphericConditions;
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import net.sf.openrocket.rocketcomponent.InstanceMap;
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import net.sf.openrocket.rocketcomponent.RecoveryDevice;
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import net.sf.openrocket.simulation.exception.SimulationException;
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import net.sf.openrocket.util.Coordinate;
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import net.sf.openrocket.util.GeodeticComputationStrategy;
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import net.sf.openrocket.util.MathUtil;
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import net.sf.openrocket.util.WorldCoordinate;
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import org.slf4j.Logger;
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import org.slf4j.LoggerFactory;
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public class BasicLandingStepper extends AbstractSimulationStepper {
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private static final Logger log = LoggerFactory.getLogger(BasicLandingStepper.class);
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private static final double RECOVERY_TIME_STEP = 0.5;
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public class BasicLandingStepper extends AbstractEulerStepper {
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@Override
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public SimulationStatus initialize(SimulationStatus status) {
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return status;
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}
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@Override
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public void step(SimulationStatus status, double maxTimeStep) throws SimulationException {
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double totalCD = 0;
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double refArea = status.getConfiguration().getReferenceArea();
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// Get the atmospheric conditions
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AtmosphericConditions atmosphere = modelAtmosphericConditions(status);
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//// Local wind speed and direction
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Coordinate windSpeed = modelWindVelocity(status);
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Coordinate airSpeed = status.getRocketVelocity().add(windSpeed);
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// Get total CD
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double mach = airSpeed.length() / atmosphere.getMachSpeed();
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protected double computeCD(SimulationStatus status) {
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// Accumulate CD for all recovery devices
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cd = 0;
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final InstanceMap imap = status.getConfiguration().getActiveInstances();
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for (RecoveryDevice c : status.getDeployedRecoveryDevices()) {
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totalCD += imap.count(c) * c.getCD(mach) * c.getArea() / refArea;
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cd += imap.count(c) * c.getCD() * c.getArea() / status.getConfiguration().getReferenceArea();
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}
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// Compute drag force
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double dynP = (0.5 * atmosphere.getDensity() * airSpeed.length2());
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double dragForce = totalCD * dynP * refArea;
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// Calculate mass data
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double rocketMass = calculateStructureMass(status).getMass();
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double motorMass = calculateMotorMass(status).getMass();
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double mass = rocketMass + motorMass;
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// Compute drag acceleration
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Coordinate linearAcceleration;
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if (airSpeed.length() > 0.001) {
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linearAcceleration = airSpeed.normalize().multiply(-dragForce / mass);
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} else {
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linearAcceleration = Coordinate.NUL;
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}
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// Add effect of gravity
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double gravity = modelGravity(status);
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linearAcceleration = linearAcceleration.sub(0, 0, gravity);
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// Add coriolis acceleration
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Coordinate coriolisAcceleration = status.getSimulationConditions().getGeodeticComputation().getCoriolisAcceleration(
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status.getRocketWorldPosition(), status.getRocketVelocity());
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linearAcceleration = linearAcceleration.add(coriolisAcceleration);
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// Select tentative time step
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double timeStep = RECOVERY_TIME_STEP;
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// adjust based on change in acceleration (ie jerk)
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final double jerk = Math.abs(linearAcceleration.sub(status.getRocketAcceleration()).multiply(1.0/status.getPreviousTimeStep()).length());
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if (jerk > MathUtil.EPSILON) {
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timeStep = Math.min(timeStep, 1.0/jerk);
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}
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// but don't let it get *too* small
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timeStep = Math.max(timeStep, MIN_TIME_STEP);
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log.trace("timeStep is " + timeStep);
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// Perform Euler integration
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Coordinate newPosition = status.getRocketPosition().add(status.getRocketVelocity().multiply(timeStep)).
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add(linearAcceleration.multiply(MathUtil.pow2(timeStep) / 2));
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// If I've hit the ground, recalculate time step and position
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if (newPosition.z < 0) {
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final double a = linearAcceleration.z;
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final double v = status.getRocketVelocity().z;
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final double z0 = status.getRocketPosition().z;
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// The new timestep is the solution of
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// 1/2 at^2 + vt + z0 = 0
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timeStep = (-v - Math.sqrt(v*v - 2*a*z0))/a;
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log.trace("ground hit changes timeStep to " + timeStep);
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newPosition = status.getRocketPosition().add(status.getRocketVelocity().multiply(timeStep)).
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add(linearAcceleration.multiply(MathUtil.pow2(timeStep) / 2));
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// avoid rounding error in new altitude
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newPosition = newPosition.setZ(0);
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}
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status.setSimulationTime(status.getSimulationTime() + timeStep);
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status.setPreviousTimeStep(timeStep);
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status.setRocketPosition(newPosition);
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status.setRocketVelocity(status.getRocketVelocity().add(linearAcceleration.multiply(timeStep)));
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status.setRocketAcceleration(linearAcceleration);
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// Update the world coordinate
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WorldCoordinate w = status.getSimulationConditions().getLaunchSite();
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w = status.getSimulationConditions().getGeodeticComputation().addCoordinate(w, status.getRocketPosition());
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status.setRocketWorldPosition(w);
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// Store data
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FlightDataBranch data = status.getFlightData();
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boolean extra = status.getSimulationConditions().isCalculateExtras();
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data.addPoint();
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data.setValue(FlightDataType.TYPE_TIME, status.getSimulationTime());
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data.setValue(FlightDataType.TYPE_ALTITUDE, status.getRocketPosition().z);
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data.setValue(FlightDataType.TYPE_POSITION_X, status.getRocketPosition().x);
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data.setValue(FlightDataType.TYPE_POSITION_Y, status.getRocketPosition().y);
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airSpeed = status.getRocketVelocity().add(windSpeed);
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if (extra) {
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data.setValue(FlightDataType.TYPE_POSITION_XY,
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MathUtil.hypot(status.getRocketPosition().x, status.getRocketPosition().y));
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data.setValue(FlightDataType.TYPE_POSITION_DIRECTION,
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Math.atan2(status.getRocketPosition().y, status.getRocketPosition().x));
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data.setValue(FlightDataType.TYPE_VELOCITY_XY,
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MathUtil.hypot(status.getRocketVelocity().x, status.getRocketVelocity().y));
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data.setValue(FlightDataType.TYPE_ACCELERATION_XY,
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MathUtil.hypot(linearAcceleration.x, linearAcceleration.y));
|
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data.setValue(FlightDataType.TYPE_ACCELERATION_TOTAL, linearAcceleration.length());
|
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|
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double Re = airSpeed.length() *
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status.getConfiguration().getLengthAerodynamic() /
|
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atmosphere.getKinematicViscosity();
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data.setValue(FlightDataType.TYPE_REYNOLDS_NUMBER, Re);
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}
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data.setValue(FlightDataType.TYPE_LATITUDE, status.getRocketWorldPosition().getLatitudeRad());
|
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data.setValue(FlightDataType.TYPE_LONGITUDE, status.getRocketWorldPosition().getLongitudeRad());
|
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data.setValue(FlightDataType.TYPE_GRAVITY, gravity);
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if (status.getSimulationConditions().getGeodeticComputation() != GeodeticComputationStrategy.FLAT) {
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data.setValue(FlightDataType.TYPE_CORIOLIS_ACCELERATION, coriolisAcceleration.length());
|
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}
|
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|
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|
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data.setValue(FlightDataType.TYPE_VELOCITY_Z, status.getRocketVelocity().z);
|
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data.setValue(FlightDataType.TYPE_ACCELERATION_Z, linearAcceleration.z);
|
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|
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data.setValue(FlightDataType.TYPE_VELOCITY_TOTAL, airSpeed.length());
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data.setValue(FlightDataType.TYPE_MACH_NUMBER, mach);
|
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|
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data.setValue(FlightDataType.TYPE_MASS, mass);
|
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data.setValue(FlightDataType.TYPE_MOTOR_MASS, motorMass);
|
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|
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data.setValue(FlightDataType.TYPE_THRUST_FORCE, 0);
|
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data.setValue(FlightDataType.TYPE_DRAG_FORCE, dragForce);
|
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|
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data.setValue(FlightDataType.TYPE_WIND_VELOCITY, windSpeed.length());
|
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data.setValue(FlightDataType.TYPE_AIR_TEMPERATURE, atmosphere.getTemperature());
|
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data.setValue(FlightDataType.TYPE_AIR_PRESSURE, atmosphere.getPressure());
|
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data.setValue(FlightDataType.TYPE_SPEED_OF_SOUND, atmosphere.getMachSpeed());
|
||||
|
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data.setValue(FlightDataType.TYPE_TIME_STEP, timeStep);
|
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data.setValue(FlightDataType.TYPE_COMPUTATION_TIME,
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(System.nanoTime() - status.getSimulationStartWallTime()) / 1000000000.0);
|
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log.trace("time " + data.getLast(FlightDataType.TYPE_TIME) + ", altitude " + data.getLast(FlightDataType.TYPE_ALTITUDE) + ", velocity " + data.getLast(FlightDataType.TYPE_VELOCITY_Z));
|
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return cd;
|
||||
}
|
||||
|
||||
}
|
||||
|
||||
@ -1,85 +0,0 @@
|
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package net.sf.openrocket.simulation;
|
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|
||||
import java.util.ArrayList;
|
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import java.util.Iterator;
|
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import java.util.Map;
|
||||
|
||||
import net.sf.openrocket.rocketcomponent.FinSet;
|
||||
import net.sf.openrocket.rocketcomponent.FlightConfiguration;
|
||||
import net.sf.openrocket.rocketcomponent.InstanceContext;
|
||||
import net.sf.openrocket.rocketcomponent.InstanceMap;
|
||||
import net.sf.openrocket.rocketcomponent.Rocket;
|
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import net.sf.openrocket.rocketcomponent.RocketComponent;
|
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import net.sf.openrocket.rocketcomponent.SymmetricComponent;
|
||||
|
||||
public class BasicTumbleStatus extends SimulationStatus {
|
||||
|
||||
// Magic constants from techdoc.pdf
|
||||
private final static double cDFin = 1.42;
|
||||
private final static double cDBt = 0.56;
|
||||
// Fin efficiency. Index is number of fins. The 0th entry is arbitrary and used to
|
||||
// offset the indexes so finEff[1] is the coefficient for one fin from the table in techdoc.pdf
|
||||
private final static double[] finEff = { 0.0, 0.5, 1.0, 1.41, 1.81, 1.73, 1.90, 1.85 };
|
||||
|
||||
private final double drag;
|
||||
|
||||
public BasicTumbleStatus(FlightConfiguration configuration,
|
||||
SimulationConditions simulationConditions) {
|
||||
super(configuration, simulationConditions);
|
||||
this.drag = computeTumbleDrag();
|
||||
}
|
||||
|
||||
public BasicTumbleStatus(SimulationStatus orig) {
|
||||
super(orig);
|
||||
if (orig instanceof BasicTumbleStatus) {
|
||||
this.drag = ((BasicTumbleStatus) orig).drag;
|
||||
} else {
|
||||
this.drag = computeTumbleDrag();
|
||||
}
|
||||
}
|
||||
|
||||
public double getTumbleDrag() {
|
||||
return drag;
|
||||
}
|
||||
|
||||
|
||||
private double computeTumbleDrag() {
|
||||
|
||||
// Computed based on Sampo's experimentation as documented in the pdf.
|
||||
|
||||
// compute the fin and body tube projected areas
|
||||
double aFins = 0.0;
|
||||
double aBt = 0.0;
|
||||
final InstanceMap imap = this.getConfiguration().getActiveInstances();
|
||||
for(Map.Entry<RocketComponent, ArrayList<InstanceContext>> entry: imap.entrySet() ) {
|
||||
final RocketComponent component = entry.getKey();
|
||||
|
||||
if (!component.isAerodynamic()) {
|
||||
continue;
|
||||
}
|
||||
|
||||
// iterate across component instances
|
||||
final ArrayList<InstanceContext> contextList = entry.getValue();
|
||||
for(InstanceContext context: contextList ) {
|
||||
|
||||
if (component instanceof FinSet) {
|
||||
final FinSet finComponent = ((FinSet) component);
|
||||
final double finArea = finComponent.getPlanformArea();
|
||||
int finCount = finComponent.getFinCount();
|
||||
|
||||
// check bounds on finCount.
|
||||
if (finCount >= finEff.length) {
|
||||
finCount = finEff.length - 1;
|
||||
}
|
||||
|
||||
aFins += finArea * finEff[finCount] / finComponent.getFinCount();
|
||||
|
||||
} else if (component instanceof SymmetricComponent) {
|
||||
aBt += ((SymmetricComponent) component).getComponentPlanformArea();
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
return (cDFin * aFins + cDBt * aBt);
|
||||
}
|
||||
}
|
||||
@ -1,165 +1,62 @@
|
||||
package net.sf.openrocket.simulation;
|
||||
|
||||
import java.util.ArrayList;
|
||||
import java.util.Iterator;
|
||||
import java.util.Map;
|
||||
|
||||
import net.sf.openrocket.models.atmosphere.AtmosphericConditions;
|
||||
import net.sf.openrocket.simulation.exception.SimulationException;
|
||||
import net.sf.openrocket.util.Coordinate;
|
||||
import net.sf.openrocket.util.GeodeticComputationStrategy;
|
||||
import net.sf.openrocket.util.MathUtil;
|
||||
import net.sf.openrocket.util.WorldCoordinate;
|
||||
import net.sf.openrocket.rocketcomponent.FinSet;
|
||||
import net.sf.openrocket.rocketcomponent.InstanceContext;
|
||||
import net.sf.openrocket.rocketcomponent.InstanceMap;
|
||||
import net.sf.openrocket.rocketcomponent.RocketComponent;
|
||||
import net.sf.openrocket.rocketcomponent.SymmetricComponent;
|
||||
|
||||
public class BasicTumbleStepper extends AbstractSimulationStepper {
|
||||
public class BasicTumbleStepper extends AbstractEulerStepper {
|
||||
|
||||
private static final double RECOVERY_TIME_STEP = 0.5;
|
||||
public double computeCD(SimulationStatus status) {
|
||||
|
||||
@Override
|
||||
public SimulationStatus initialize(SimulationStatus original) {
|
||||
BasicTumbleStatus status = new BasicTumbleStatus(original);
|
||||
status.setWarnings(original.getWarnings());
|
||||
// Computed based on Sampo's experimentation as documented in techdoc.pdf.
|
||||
|
||||
return status;
|
||||
}
|
||||
// Magic constants from techdoc.pdf
|
||||
final double cDFin = 1.42;
|
||||
final double cDBt = 0.56;
|
||||
// Fin efficiency. Index is number of fins. The 0th entry is arbitrary and used to
|
||||
// offset the indexes so finEff[1] is the coefficient for one fin from the table in techdoc.pdf
|
||||
final double[] finEff = { 0.0, 0.5, 1.0, 1.41, 1.81, 1.73, 1.90, 1.85 };
|
||||
|
||||
@Override
|
||||
public void step(SimulationStatus status, double maxTimeStep) throws SimulationException {
|
||||
// compute the fin and body tube projected areas
|
||||
double aFins = 0.0;
|
||||
double aBt = 0.0;
|
||||
final InstanceMap imap = status.getConfiguration().getActiveInstances();
|
||||
for(Map.Entry<RocketComponent, ArrayList<InstanceContext>> entry: imap.entrySet() ) {
|
||||
final RocketComponent component = entry.getKey();
|
||||
|
||||
// Get the atmospheric conditions
|
||||
AtmosphericConditions atmosphere = modelAtmosphericConditions(status);
|
||||
if (!component.isAerodynamic()) {
|
||||
continue;
|
||||
}
|
||||
|
||||
//// Local wind speed and direction
|
||||
Coordinate windSpeed = modelWindVelocity(status);
|
||||
Coordinate airSpeed = status.getRocketVelocity().add(windSpeed);
|
||||
// iterate across component instances
|
||||
final ArrayList<InstanceContext> contextList = entry.getValue();
|
||||
for(InstanceContext context: contextList ) {
|
||||
|
||||
// Get total CD
|
||||
double mach = airSpeed.length() / atmosphere.getMachSpeed();
|
||||
if (component instanceof FinSet) {
|
||||
final FinSet finComponent = ((FinSet) component);
|
||||
final double finArea = finComponent.getPlanformArea();
|
||||
int finCount = finComponent.getFinCount();
|
||||
|
||||
double tumbleDrag = ((BasicTumbleStatus)status).getTumbleDrag();
|
||||
// check bounds on finCount.
|
||||
if (finCount >= finEff.length) {
|
||||
finCount = finEff.length - 1;
|
||||
}
|
||||
|
||||
// Compute drag force
|
||||
double dynP = (0.5 * atmosphere.getDensity() * airSpeed.length2());
|
||||
double dragForce = tumbleDrag * dynP;
|
||||
aFins += finArea * finEff[finCount] / finComponent.getFinCount();
|
||||
|
||||
// n.b. this is constant, and could be calculated once at the beginning of this simulation branch...
|
||||
double rocketMass = calculateStructureMass(status).getMass();
|
||||
double motorMass = calculateMotorMass(status).getMass();
|
||||
|
||||
double mass = rocketMass + motorMass;
|
||||
|
||||
// Compute drag acceleration
|
||||
Coordinate linearAcceleration;
|
||||
if (airSpeed.length() > 0.001) {
|
||||
linearAcceleration = airSpeed.normalize().multiply(-dragForce / mass);
|
||||
} else {
|
||||
linearAcceleration = Coordinate.NUL;
|
||||
} else if (component instanceof SymmetricComponent) {
|
||||
aBt += ((SymmetricComponent) component).getComponentPlanformArea();
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// Add effect of gravity
|
||||
double gravity = modelGravity(status);
|
||||
linearAcceleration = linearAcceleration.sub(0, 0, gravity);
|
||||
|
||||
|
||||
// Add coriolis acceleration
|
||||
Coordinate coriolisAcceleration = status.getSimulationConditions().getGeodeticComputation().getCoriolisAcceleration(
|
||||
status.getRocketWorldPosition(), status.getRocketVelocity());
|
||||
linearAcceleration = linearAcceleration.add(coriolisAcceleration);
|
||||
|
||||
|
||||
|
||||
// Select time step
|
||||
double timeStep = MathUtil.min(0.5 / linearAcceleration.length(), RECOVERY_TIME_STEP);
|
||||
|
||||
// Perform Euler integration
|
||||
Coordinate newPosition = status.getRocketPosition().add(status.getRocketVelocity().multiply(timeStep)).
|
||||
add(linearAcceleration.multiply(MathUtil.pow2(timeStep) / 2));
|
||||
|
||||
// If I've hit the ground, recalculate time step and position
|
||||
if (newPosition.z < 0) {
|
||||
|
||||
final double a = linearAcceleration.z;
|
||||
final double v = status.getRocketVelocity().z;
|
||||
final double z0 = status.getRocketPosition().z;
|
||||
|
||||
// The new timestep is the solution of
|
||||
// 1/2 at^2 + vt + z0 = 0
|
||||
timeStep = (-v - Math.sqrt(v*v - 2*a*z0))/a;
|
||||
|
||||
newPosition = status.getRocketPosition().add(status.getRocketVelocity().multiply(timeStep)).
|
||||
add(linearAcceleration.multiply(MathUtil.pow2(timeStep) / 2));
|
||||
|
||||
// avoid rounding error in new altitude
|
||||
newPosition = newPosition.setZ(0);
|
||||
}
|
||||
|
||||
status.setRocketPosition(status.getRocketPosition().add(status.getRocketVelocity().multiply(timeStep)).
|
||||
add(linearAcceleration.multiply(MathUtil.pow2(timeStep) / 2)));
|
||||
status.setRocketVelocity(status.getRocketVelocity().add(linearAcceleration.multiply(timeStep)));
|
||||
status.setSimulationTime(status.getSimulationTime() + timeStep);
|
||||
|
||||
|
||||
// Update the world coordinate
|
||||
WorldCoordinate w = status.getSimulationConditions().getLaunchSite();
|
||||
w = status.getSimulationConditions().getGeodeticComputation().addCoordinate(w, status.getRocketPosition());
|
||||
status.setRocketWorldPosition(w);
|
||||
|
||||
|
||||
// Store data
|
||||
FlightDataBranch data = status.getFlightData();
|
||||
boolean extra = status.getSimulationConditions().isCalculateExtras();
|
||||
data.addPoint();
|
||||
|
||||
data.setValue(FlightDataType.TYPE_TIME, status.getSimulationTime());
|
||||
data.setValue(FlightDataType.TYPE_ALTITUDE, status.getRocketPosition().z);
|
||||
data.setValue(FlightDataType.TYPE_POSITION_X, status.getRocketPosition().x);
|
||||
data.setValue(FlightDataType.TYPE_POSITION_Y, status.getRocketPosition().y);
|
||||
if (extra) {
|
||||
data.setValue(FlightDataType.TYPE_POSITION_XY,
|
||||
MathUtil.hypot(status.getRocketPosition().x, status.getRocketPosition().y));
|
||||
data.setValue(FlightDataType.TYPE_POSITION_DIRECTION,
|
||||
Math.atan2(status.getRocketPosition().y, status.getRocketPosition().x));
|
||||
|
||||
data.setValue(FlightDataType.TYPE_VELOCITY_XY,
|
||||
MathUtil.hypot(status.getRocketVelocity().x, status.getRocketVelocity().y));
|
||||
data.setValue(FlightDataType.TYPE_ACCELERATION_XY,
|
||||
MathUtil.hypot(linearAcceleration.x, linearAcceleration.y));
|
||||
|
||||
data.setValue(FlightDataType.TYPE_ACCELERATION_TOTAL, linearAcceleration.length());
|
||||
|
||||
double Re = airSpeed.length() *
|
||||
status.getConfiguration().getLengthAerodynamic() /
|
||||
atmosphere.getKinematicViscosity();
|
||||
data.setValue(FlightDataType.TYPE_REYNOLDS_NUMBER, Re);
|
||||
}
|
||||
|
||||
|
||||
data.setValue(FlightDataType.TYPE_LATITUDE, status.getRocketWorldPosition().getLatitudeRad());
|
||||
data.setValue(FlightDataType.TYPE_LONGITUDE, status.getRocketWorldPosition().getLongitudeRad());
|
||||
data.setValue(FlightDataType.TYPE_GRAVITY, gravity);
|
||||
|
||||
if (status.getSimulationConditions().getGeodeticComputation() != GeodeticComputationStrategy.FLAT) {
|
||||
data.setValue(FlightDataType.TYPE_CORIOLIS_ACCELERATION, coriolisAcceleration.length());
|
||||
}
|
||||
|
||||
|
||||
data.setValue(FlightDataType.TYPE_VELOCITY_Z, status.getRocketVelocity().z);
|
||||
data.setValue(FlightDataType.TYPE_ACCELERATION_Z, linearAcceleration.z);
|
||||
|
||||
data.setValue(FlightDataType.TYPE_VELOCITY_TOTAL, airSpeed.length());
|
||||
data.setValue(FlightDataType.TYPE_MACH_NUMBER, mach);
|
||||
|
||||
data.setValue(FlightDataType.TYPE_MASS, mass);
|
||||
data.setValue(FlightDataType.TYPE_MOTOR_MASS, motorMass);
|
||||
|
||||
data.setValue(FlightDataType.TYPE_THRUST_FORCE, 0);
|
||||
data.setValue(FlightDataType.TYPE_DRAG_FORCE, dragForce);
|
||||
|
||||
data.setValue(FlightDataType.TYPE_WIND_VELOCITY, windSpeed.length());
|
||||
data.setValue(FlightDataType.TYPE_AIR_TEMPERATURE, atmosphere.getTemperature());
|
||||
data.setValue(FlightDataType.TYPE_AIR_PRESSURE, atmosphere.getPressure());
|
||||
data.setValue(FlightDataType.TYPE_SPEED_OF_SOUND, atmosphere.getMachSpeed());
|
||||
|
||||
data.setValue(FlightDataType.TYPE_TIME_STEP, timeStep);
|
||||
data.setValue(FlightDataType.TYPE_COMPUTATION_TIME,
|
||||
(System.nanoTime() - status.getSimulationStartWallTime()) / 1000000000.0);
|
||||
return (cDFin * aFins + cDBt * aBt)/status.getConfiguration().getReferenceArea();
|
||||
}
|
||||
|
||||
}
|
||||
|
||||
Loading…
x
Reference in New Issue
Block a user