/// <summary>
/// All cells belonging to the same LTS cluster (clusters 0..n) are
/// assigned to the same performance class. The cluster performing the
/// largest time-steps corresponds to performance class 0, the cluster with
/// the smallest time-steps to performance class n.
/// </summary>
/// <param name="program"></param>
/// <returns></returns>
public (int noOfClasses, int[] cellToPerformanceClassMap) ClassifyCells(IProgram <CNSControl> program)
{
AdamsBashforthLTS ltsTimeStepper = program.TimeStepper as AdamsBashforthLTS;
if (ltsTimeStepper == null)
{
throw new Exception("LTS cell classifier is only sensible for LTS runs.");
}
int noOfClasses = ltsTimeStepper.CurrentClustering.NumberOfClusters;
int[] cellToPerformanceClassMap = new int[program.Grid.NoOfUpdateCells];
for (int i = 0; i < ltsTimeStepper.CurrentClustering.NumberOfClusters; i++)
{
foreach (Chunk chunk in ltsTimeStepper.CurrentClustering.Clusters[i].VolumeMask)
{
foreach (int cell in chunk.Elements)
{
cellToPerformanceClassMap[cell] = i;
}
}
}
return(noOfClasses, cellToPerformanceClassMap);
}
protected override void CreateEquationsAndSolvers(GridUpdateDataVaultBase L)
{
SpatialOperator diffOp = new SpatialOperator(1, 0, 1, QuadOrderFunc.MaxDegTimesTwo(), "u", "codom1");
diffOp.EquationComponents["codom1"].Add(new ScalarTransportFlux());
diffOp.Commit();
CustomTimestepConstraint = new SurrogateConstraint(GridData, dt_input, dt_input, double.MaxValue, endTime);
if (LTS)
{
AdamsBashforthLTS ltsTimeStepper = new AdamsBashforthLTS(
diffOp,
new CoordinateMapping(u),
null,
ABorder,
numOfSubgrids,
fluxCorrection: true,
reclusteringInterval: 0,
timeStepConstraints: new List <TimeStepConstraint>()
{
CustomTimestepConstraint
});
timeStepper = ltsTimeStepper;
}
else if (ALTS)
{
AdamsBashforthLTS ltsTimeStepper = new AdamsBashforthLTS(
diffOp,
new CoordinateMapping(u),
null,
ABorder,
numOfSubgrids,
fluxCorrection: false,
reclusteringInterval: 1,
timeStepConstraints: new List <TimeStepConstraint>()
{
CustomTimestepConstraint
});
timeStepper = ltsTimeStepper;
}
else
{
timeStepper = new AdamsBashforth(diffOp, new CoordinateMapping(u), null, ABorder);
//timeStepper = new RungeKutta(RungeKutta.RungeKuttaScheme.Heun, diffOp, new CoordinateMapping(u),null);
//timeStepper = RungeKutta.Factory(ABorder, diffOp, new CoordinateMapping(u));
}
}
/// <summary>
/// Creates the appropriate time-stepper for a given
/// <paramref name="timeStepperType"/>
/// </summary>
/// <param name="timeStepperType">
/// The type of the time-stepper (e.g., Runge-Kutta) to be created
/// </param>
/// <param name="control">
/// Configuration options
/// </param>
/// <param name="equationSystem">
/// The equation system to be solved
/// </param>
/// <param name="fieldSet">
/// Fields affected by the time-stepper
/// </param>
/// <param name="parameterMap">
/// Fields serving as parameter for the time-stepper.
/// </param>
/// <param name="speciesMap">
/// Mapping of different species inside the domain
/// </param>
/// <param name="program"></param>
/// <returns>
/// Depending on <paramref name="timeStepperType"/>, an appropriate
/// implementation of <see cref="ITimeStepper"/>.
/// </returns>
/// <remarks>
/// Currently limiting is not supported for Adams-Bashforth methods
/// </remarks>
public static ITimeStepper Instantiate <T>(
this ExplicitSchemes timeStepperType,
CNSControl control,
OperatorFactory equationSystem,
CNSFieldSet fieldSet,
CoordinateMapping parameterMap,
ISpeciesMap speciesMap,
IProgram <T> program)
where T : CNSControl, new()
{
CoordinateMapping variableMap = new CoordinateMapping(fieldSet.ConservativeVariables);
IBMControl ibmControl = control as IBMControl;
IBMOperatorFactory ibmFactory = equationSystem as IBMOperatorFactory;
if (control.DomainType != DomainTypes.Standard &&
(ibmFactory == null || ibmControl == null))
{
throw new Exception();
}
ITimeStepper timeStepper;
switch (timeStepperType)
{
case ExplicitSchemes.RungeKutta when control.DomainType == DomainTypes.Standard:
timeStepper = new RungeKutta(
RungeKutta.GetDefaultScheme(control.ExplicitOrder),
equationSystem.GetJoinedOperator().ToSpatialOperator(fieldSet),
variableMap,
parameterMap,
equationSystem.GetJoinedOperator().CFLConstraints);
break;
case ExplicitSchemes.RungeKutta:
timeStepper = ibmControl.TimesteppingStrategy.CreateRungeKuttaTimeStepper(
ibmControl,
equationSystem,
fieldSet,
parameterMap,
speciesMap,
equationSystem.GetJoinedOperator().CFLConstraints);
break;
case ExplicitSchemes.AdamsBashforth when control.DomainType == DomainTypes.Standard:
timeStepper = new AdamsBashforth(
equationSystem.GetJoinedOperator().ToSpatialOperator(fieldSet),
variableMap,
parameterMap,
control.ExplicitOrder,
equationSystem.GetJoinedOperator().CFLConstraints);
break;
case ExplicitSchemes.AdamsBashforth:
timeStepper = new IBMAdamsBashforth(
ibmFactory.GetJoinedOperator().ToSpatialOperator(fieldSet),
ibmFactory.GetImmersedBoundaryOperator().ToSpatialOperator(fieldSet),
variableMap,
parameterMap,
speciesMap,
ibmControl,
equationSystem.GetJoinedOperator().CFLConstraints);
break;
case ExplicitSchemes.LTS when control.DomainType == DomainTypes.Standard:
timeStepper = new AdamsBashforthLTS(
equationSystem.GetJoinedOperator().ToSpatialOperator(fieldSet),
variableMap,
parameterMap,
control.ExplicitOrder,
control.NumberOfSubGrids,
equationSystem.GetJoinedOperator().CFLConstraints,
reclusteringInterval: control.ReclusteringInterval,
fluxCorrection: control.FluxCorrection,
saveToDBCallback: program.SaveToDatabase,
maxNumOfSubSteps: control.maxNumOfSubSteps,
forceReclustering: control.forceReclustering,
logging: control.WriteLTSLog,
consoleOutput: control.WriteLTSConsoleOutput);
break;
case ExplicitSchemes.LTS:
timeStepper = new IBMAdamsBashforthLTS(
equationSystem.GetJoinedOperator().ToSpatialOperator(fieldSet),
ibmFactory.GetImmersedBoundaryOperator().ToSpatialOperator(fieldSet),
variableMap,
parameterMap,
speciesMap,
ibmControl,
equationSystem.GetJoinedOperator().CFLConstraints,
reclusteringInterval: control.ReclusteringInterval,
fluxCorrection: control.FluxCorrection,
maxNumOfSubSteps: control.maxNumOfSubSteps,
forceReclustering: control.forceReclustering,
logging: control.WriteLTSLog,
consoleOutput: control.WriteLTSConsoleOutput);
break;
case ExplicitSchemes.Rock4 when control.DomainType == DomainTypes.Standard:
timeStepper = new ROCK4(equationSystem.GetJoinedOperator().ToSpatialOperator(fieldSet), new CoordinateVector(variableMap), null);
break;
case ExplicitSchemes.SSP54 when control.DomainType == DomainTypes.Standard:
timeStepper = new RungeKutta(
RungeKuttaScheme.SSP54,
equationSystem.GetJoinedOperator().ToSpatialOperator(fieldSet),
variableMap,
parameterMap,
equationSystem.GetJoinedOperator().CFLConstraints);
break;
case ExplicitSchemes.RKC84 when control.DomainType == DomainTypes.Standard:
timeStepper = new RungeKutta(
RungeKuttaScheme.RKC84,
equationSystem.GetJoinedOperator().ToSpatialOperator(fieldSet),
variableMap,
parameterMap,
equationSystem.GetJoinedOperator().CFLConstraints);
break;
case ExplicitSchemes.None:
throw new System.ArgumentException("Cannot instantiate empty scheme");
default:
throw new NotImplementedException(String.Format(
"Explicit time stepper type '{0}' not implemented for domain type '{1}'",
timeStepperType,
control.DomainType));
}
// Make sure shock sensor is updated before every flux evaluation
if (control.CNSShockSensor != null)
{
ExplicitEuler explicitEulerBasedTimestepper = timeStepper as ExplicitEuler;
if (explicitEulerBasedTimestepper == null)
{
throw new Exception(String.Format(
"Shock-capturing currently not implemented for time-steppers of type '{0}'",
timeStepperType));
}
explicitEulerBasedTimestepper.OnBeforeComputeChangeRate += delegate(double absTime, double relTime) {
// Note: Only shock sensor is updated, _NOT_ the corresponding variable
program.Control.CNSShockSensor.UpdateSensorValues(
program.WorkingSet.AllFields,
program.SpeciesMap,
explicitEulerBasedTimestepper.SubGrid.VolumeMask);
// Note: When being called, artificial viscosity is updated in the _ENTIRE_ (fluid) domain
var avField = program.WorkingSet.DerivedFields[CNSVariables.ArtificialViscosity];
CNSVariables.ArtificialViscosity.UpdateFunction(avField, program.SpeciesMap.SubGrid.VolumeMask, program);
// Test
//double sensorNorm = program.WorkingSet.DerivedFields[CNSVariables.ShockSensor].L2Norm();
//double avNorm = program.WorkingSet.DerivedFields[CNSVariables.ArtificialViscosity].L2Norm();
//Console.WriteLine("\r\nThis is OnBeforeComputeChangeRate");
//Console.WriteLine("SensorNeu: {0}", sensorNorm);
//Console.WriteLine("AVNeu: {0}", avNorm);
};
}
// Make sure limiter is applied after each modification of conservative variables
if (control.Limiter != null)
{
ExplicitEuler explicitEulerBasedTimestepper = timeStepper as ExplicitEuler;
if (explicitEulerBasedTimestepper == null)
{
throw new Exception(String.Format(
"Limiting currently not implemented for time-steppers of type '{0}~",
timeStepperType));
}
explicitEulerBasedTimestepper.OnAfterFieldUpdate +=
(t, f) => control.Limiter.LimitFieldValues(program.WorkingSet.ConservativeVariables, program.WorkingSet.DerivedFields.Values);
}
return(timeStepper);
}
