int TimestepSchemeStrang::GetSubStepCount() const {
HorizontalDynamics * pHorizontalDynamics =
m_model.GetHorizontalDynamics();
if (pHorizontalDynamics == NULL) {
_EXCEPTIONT("HorizontalDynamics has not been initialized");
}
int nHorizontalDynamicsSubSteps =
pHorizontalDynamics->GetSubStepAfterSubCycleCount();
return (m_nExplicitSubSteps + nHorizontalDynamicsSubSteps + 1);
}
int TimestepSchemeStrang::SubStep(
bool fFirstStep,
bool fLastStep,
const Time & time,
double dDeltaT,
int iSubStep
) {
Grid * pGrid = m_model.GetGrid();
HorizontalDynamics * pHorizontalDynamics = m_model.GetHorizontalDynamics();
VerticalDynamics * pVerticalDynamics = m_model.GetVerticalDynamics();
if (pGrid == NULL) {
_EXCEPTIONT("Model Grid has not been initialized");
}
if (pHorizontalDynamics == NULL) {
_EXCEPTIONT("Model HorizontalDynamics has not been initialized");
}
if (pVerticalDynamics == NULL) {
_EXCEPTIONT("Model VerticalDynamics has not been initialized");
}
// Half a time step
double dHalfDeltaT = 0.5 * dDeltaT;
// Number of HorizontalDynamics substeps
int nHorizontalDynamicsSubSteps =
pHorizontalDynamics->GetSubStepAfterSubCycleCount();
// Vertical timestep
if (iSubStep == 0) {
// Vertical timestep
if (fFirstStep) {
pVerticalDynamics->StepImplicit(0, 0, time, dHalfDeltaT);
} else {
pGrid->LinearCombineData(m_dCarryoverCombination, 0, DataType_State);
pGrid->LinearCombineData(m_dCarryoverCombination, 0, DataType_Tracers);
pVerticalDynamics->FilterNegativeTracers(0);
}
}
// Forward Euler
if (m_eExplicitDiscretization == ForwardEuler) {
if (iSubStep == 0) {
pGrid->CopyData(0, 4, DataType_State);
pGrid->CopyData(0, 4, DataType_Tracers);
pHorizontalDynamics->StepExplicit(0, 4, time, dDeltaT);
pVerticalDynamics->StepExplicit(0, 4, time, dDeltaT);
return 4;
}
// Explicit fourth-order Runge-Kutta
} else if (m_eExplicitDiscretization == RungeKutta4) {
if (iSubStep == 0) {
pGrid->CopyData(0, 1, DataType_State);
pGrid->CopyData(0, 1, DataType_Tracers);
pHorizontalDynamics->StepExplicit(0, 1, time, dHalfDeltaT);
pVerticalDynamics->StepExplicit(0, 1, time, dHalfDeltaT);
return 1;
} else if (iSubStep == 1) {
pGrid->CopyData(0, 2, DataType_State);
pGrid->CopyData(0, 2, DataType_Tracers);
pHorizontalDynamics->StepExplicit(1, 2, time, dHalfDeltaT);
pVerticalDynamics->StepExplicit(1, 2, time, dHalfDeltaT);
return 2;
} else if (iSubStep == 2) {
pGrid->CopyData(0, 3, DataType_State);
pGrid->CopyData(0, 3, DataType_Tracers);
pHorizontalDynamics->StepExplicit(2, 3, time, dDeltaT);
pVerticalDynamics->StepExplicit(2, 3, time, dDeltaT);
return 3;
} else if (iSubStep == 3) {
pGrid->LinearCombineData(m_dRK4Combination, 4, DataType_State);
pGrid->LinearCombineData(m_dRK4Combination, 4, DataType_Tracers);
pHorizontalDynamics->StepExplicit(3, 4, time, dDeltaT / 6.0);
pVerticalDynamics->StepExplicit(3, 4, time, dDeltaT / 6.0);
return 4;
}
// Explicit strong stability preserving third-order Runge-Kutta
} else if (m_eExplicitDiscretization == RungeKuttaSSP3) {
if (iSubStep == 0) {
pGrid->CopyData(0, 1, DataType_State);
pGrid->CopyData(0, 1, DataType_Tracers);
pHorizontalDynamics->StepExplicit(0, 1, time, dDeltaT);
pVerticalDynamics->StepExplicit(0, 1, time, dDeltaT);
return 1;
} else if (iSubStep == 1) {
pGrid->LinearCombineData(m_dSSPRK3CombinationA, 2, DataType_State);
pGrid->LinearCombineData(m_dSSPRK3CombinationA, 2, DataType_Tracers);
pHorizontalDynamics->StepExplicit(1, 2, time, 0.25 * dDeltaT);
pVerticalDynamics->StepExplicit(1, 2, time, 0.25 * dDeltaT);
return 2;
} else if (iSubStep == 2) {
pGrid->LinearCombineData(m_dSSPRK3CombinationB, 4, DataType_State);
pGrid->LinearCombineData(m_dSSPRK3CombinationB, 4, DataType_Tracers);
pHorizontalDynamics->StepExplicit(2, 4, time, (2.0/3.0) * dDeltaT);
pVerticalDynamics->StepExplicit(2, 4, time, (2.0/3.0) * dDeltaT);
return 4;
}
// Explicit Kinnmark, Gray and Ullrich third-order five-stage Runge-Kutta
} else if (m_eExplicitDiscretization == KinnmarkGrayUllrich35) {
if (iSubStep == 0) {
pGrid->CopyData(0, 1, DataType_State);
pGrid->CopyData(0, 1, DataType_Tracers);
pHorizontalDynamics->StepExplicit(0, 1, time, dDeltaT / 5.0);
pVerticalDynamics->StepExplicit(0, 1, time, dDeltaT / 5.0);
return 1;
} else if (iSubStep == 1) {
pGrid->CopyData(0, 2, DataType_State);
pGrid->CopyData(0, 2, DataType_Tracers);
pHorizontalDynamics->StepExplicit(1, 2, time, dDeltaT / 5.0);
pVerticalDynamics->StepExplicit(1, 2, time, dDeltaT / 5.0);
return 2;
} else if (iSubStep == 2) {
pGrid->CopyData(0, 3, DataType_State);
pGrid->CopyData(0, 3, DataType_Tracers);
pHorizontalDynamics->StepExplicit(2, 3, time, dDeltaT / 3.0);
pVerticalDynamics->StepExplicit(2, 3, time, dDeltaT / 3.0);
return 3;
} else if (iSubStep == 3) {
pGrid->CopyData(0, 2, DataType_State);
pGrid->CopyData(0, 2, DataType_Tracers);
pHorizontalDynamics->StepExplicit(3, 2, time, 2.0 * dDeltaT / 3.0);
pVerticalDynamics->StepExplicit(3, 2, time, 2.0 * dDeltaT / 3.0);
return 2;
} else if (iSubStep == 4) {
pGrid->LinearCombineData(
m_dKinnmarkGrayUllrichCombination, 4, DataType_State);
pGrid->LinearCombineData(
m_dKinnmarkGrayUllrichCombination, 4, DataType_Tracers);
pHorizontalDynamics->StepExplicit(2, 4, time, 3.0 * dDeltaT / 4.0);
pVerticalDynamics->StepExplicit(2, 4, time, 3.0 * dDeltaT / 4.0);
return 4;
}
// Explicit strong stability preserving five-stage third-order Runge-Kutta
} else if (m_eExplicitDiscretization == RungeKuttaSSPRK53) {
if (iSubStep == 0) {
const double dStepOne = 0.377268915331368;
pGrid->CopyData(0, 1, DataType_State);
pGrid->CopyData(0, 1, DataType_Tracers);
pHorizontalDynamics->StepExplicit(0, 1, time, dStepOne * dDeltaT);
pVerticalDynamics->StepExplicit(0, 1, time, dStepOne * dDeltaT);
return 1;
} else if (iSubStep == 1) {
const double dStepOne = 0.377268915331368;
pGrid->CopyData(1, 2, DataType_State);
pGrid->CopyData(1, 2, DataType_Tracers);
pHorizontalDynamics->StepExplicit(1, 2, time, dStepOne * dDeltaT);
pVerticalDynamics->StepExplicit(1, 2, time, dStepOne * dDeltaT);
return 2;
} else if (iSubStep == 2) {
const double dStepThree = 0.242995220537396;
pGrid->LinearCombineData(m_dSSPRK53CombinationA, 3, DataType_State);
pGrid->LinearCombineData(m_dSSPRK53CombinationA, 3, DataType_Tracers);
pHorizontalDynamics->StepExplicit(2, 3, time, dStepThree * dDeltaT);
pVerticalDynamics->StepExplicit(2, 3, time, dStepThree * dDeltaT);
return 3;
} else if (iSubStep == 3) {
const double dStepFour = 0.238458932846290;
pGrid->LinearCombineData(m_dSSPRK53CombinationB, 0, DataType_State);
pGrid->LinearCombineData(m_dSSPRK53CombinationB, 0, DataType_Tracers);
pHorizontalDynamics->StepExplicit(3, 0, time, dStepFour * dDeltaT);
pVerticalDynamics->StepExplicit(3, 0, time, dStepFour * dDeltaT);
return 0;
} else if (iSubStep == 4) {
const double dStepFive = 0.287632146308408;
pGrid->LinearCombineData(m_dSSPRK53CombinationC, 4, DataType_State);
pGrid->LinearCombineData(m_dSSPRK53CombinationC, 4, DataType_Tracers);
pHorizontalDynamics->StepExplicit(0, 4, time, dStepFive * dDeltaT);
pVerticalDynamics->StepExplicit(0, 4, time, dStepFive * dDeltaT);
return 4;
}
// Fixers, filters and diffusion
} else if (
(iSubStep >= m_nExplicitSubSteps) &&
(iSubStep < m_nExplicitSubSteps + nHorizontalDynamicsSubSteps)
) {
return pHorizontalDynamics->SubStepAfterSubCycle(
4, 1, 2, time, dDeltaT, iSubStep - m_nExplicitSubSteps);
// Vertical timestep
} else if (
iSubStep == m_nExplicitSubSteps + nHorizontalDynamicsSubSteps
) {
pGrid->CopyData(1, 0, DataType_State);
pGrid->CopyData(1, 0, DataType_Tracers);
pVerticalDynamics->StepImplicit(0, 0, time, 0.5 * dDeltaT);
if (!fLastStep) {
pGrid->LinearCombineData(m_dCarryoverFinal, 1, DataType_State);
pGrid->LinearCombineData(m_dCarryoverFinal, 1, DataType_Tracers);
}
#pragma message "Merge this vertical timestep in above"
return (-1);
}
// Invalid substep
_EXCEPTIONT("Invalid iSubStep");
}
