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the adaptive time stepping utility classes.

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This commit is contained in:
Robert K 2014-10-06 14:06:07 +02:00
parent 879dddc9b6
commit 5af49ed90b
6 changed files with 459 additions and 1 deletions
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3
opm/core/simulator/AdaptiveSimulatorTimer.hpp
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@ -57,12 +57,13 @@ namespace Opm
}
/// \brief advance time by currentStepLength
void advance()
AdaptiveSimulatorTimer& operator++ ()
{
++current_step_;
current_time_ += dt_;
// store used time step sizes
steps_.push_back( dt_ );
return *this;
}
/// \brief provide and estimate for new time step size

48
opm/core/simulator/AdaptiveTimeStepping.hpp Normal file
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#ifndef OPM_SUBSTEPPING_HEADER_INCLUDED
#define OPM_SUBSTEPPING_HEADER_INCLUDED
#include <iostream>
#include <utility>
#include <opm/core/utility/parameters/ParameterGroup.hpp>
#include <opm/core/utility/ErrorMacros.hpp>
#include <opm/core/simulator/TimeStepControlInterface.hpp>
namespace Opm {
// AdaptiveTimeStepping
//---------------------
class AdaptiveTimeStepping
{
public:
//! \brief contructor taking parameter object
AdaptiveTimeStepping( const parameter::ParameterGroup& param );
/** \brief step method that acts like the solver::step method
in a sub cycle of time steps
\param solver solver object that must implement a method step( dt, state, well_state )
\param state current state of the solution variables
\param well_state additional well state object
\param time current simulation time
\param timestep current time step length that is to be sub cycled
*/
template <class Solver, class State, class WellState>
void step( Solver& solver, State& state, WellState& well_state,
const double time, const double timestep );
protected:
typedef std::unique_ptr< TimeStepControlInterface > TimeStepControlType;
TimeStepControlType timeStepControl_; //!< time step control object
const double restart_factor_; //!< factor to multiply time step with when solver fails to converge
const int solver_restart_max_; //!< how many restart of solver are allowed
const bool solver_verbose_; //!< solver verbosity
const bool timestep_verbose_; //!< timestep verbosity
double last_timestep_; //!< size of last timestep
};
}
#include <opm/core/simulator/AdaptiveTimeStepping_impl.hpp>
#endif

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opm/core/simulator/AdaptiveTimeStepping_impl.hpp Normal file
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#ifndef OPM_ADAPTIVETIMESTEPPING_IMPL_HEADER_INCLUDED
#define OPM_ADAPTIVETIMESTEPPING_IMPL_HEADER_INCLUDED
#include <iostream>
#include <string>
#include <utility>
#include <opm/core/simulator/AdaptiveSimulatorTimer.hpp>
#include <opm/core/simulator/PIDTimeStepControl.hpp>
namespace Opm {
// AdaptiveTimeStepping
//---------------------
AdaptiveTimeStepping::AdaptiveTimeStepping( const parameter::ParameterGroup& param )
: timeStepControl_()
, restart_factor_( param.getDefault("solver.restartfactor", double(0.1) ) )
, solver_restart_max_( param.getDefault("solver.restart", int(3) ) )
, solver_verbose_( param.getDefault("solver.verbose", bool(false) ) )
, timestep_verbose_( param.getDefault("timestep.verbose", bool(false) ) )
, last_timestep_( std::numeric_limits< double >::max() )
{
// valid are "pid" and "pid+iteration"
std::string control = param.getDefault("timestep.control", std::string("pid") );
const double tol = param.getDefault("timestep.control.tol", double(1e-3) );
if( control == "pid" )
timeStepControl_ = TimeStepControlType( new PIDTimeStepControl( tol ) );
else if ( control == "pid+iteration" )
{
const int iterations = param.getDefault("timestep.control.targetiteration", int(25) );
timeStepControl_ = TimeStepControlType( new PIDAndIterationCountTimeStepControl( iterations, tol ) );
}
else
OPM_THROW(std::runtime_error,"Unsupported time step control selected "<< control );
}
template <class Solver, class State, class WellState>
void AdaptiveTimeStepping::
step( Solver& solver, State& state, WellState& well_state,
const double time, const double timestep )
{
// create adaptive step timer with previously used sub step size
AdaptiveSimulatorTimer timer( time, time+timestep, last_timestep_ );
// copy states in case solver has to be restarted (to be revised)
State last_state( state );
WellState last_well_state( well_state );
// counter for solver restarts
int restarts = 0;
// sub step time loop
while( ! timer.done() )
{
// initialize time step control in case current state is needed later
timeStepControl_->initialize( state );
int linearIterations = -1;
try {
// (linearIterations < 0 means on convergence in solver)
linearIterations = solver.step(timer.currentStepLength(), state, well_state);
if( solver_verbose_ ) {
// report number of linear iterations
std::cout << "Overall linear iterations used: " << linearIterations << std::endl;
}
}
catch (Opm::NumericalProblem)
{
// since linearIterations is < 0 this will restart the solver
}
// (linearIterations < 0 means on convergence in solver)
if( linearIterations >= 0 )
{
// advance by current dt
++timer;
// compute new time step estimate
const double dtEstimate =
timeStepControl_->computeTimeStepSize( timer.currentStepLength(), linearIterations, state );
if( timestep_verbose_ )
std::cout << "Suggested time step size = " << dtEstimate/86400.0 << " (days)" << std::endl;
// set new time step length
timer.provideTimeStepEstimate( dtEstimate );
// update states
last_state = state ;
last_well_state = well_state;
}
else // in case of no convergence
{
// increase restart counter
if( restarts >= solver_restart_max_ ) {
OPM_THROW(Opm::NumericalProblem,"Solver failed to converge after " << restarts << " restarts.");
}
const double newTimeStep = restart_factor_ * timer.currentStepLength();
// we need to revise this
timer.provideTimeStepEstimate( newTimeStep );
if( solver_verbose_ )
std::cerr << "Solver convergence failed, restarting solver with new time step ("<< newTimeStep <<" days)." << std::endl;
// reset states
state = last_state;
well_state = last_well_state;
++restarts;
}
}
// store last small time step for next reportStep
last_timestep_ = timer.suggestedAverage();
if( timestep_verbose_ )
{
timer.report( std::cout );
std::cout << "Last suggested step size = " << last_timestep_/86400.0 << " (days)" << std::endl;
}
if( ! std::isfinite( last_timestep_ ) ) // check for NaN
last_timestep_ = timestep;
}
}
#endif

121
opm/core/simulator/PIDTimeStepControl.cpp Normal file
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/*
Copyright 2014 IRIS AS
This file is part of the Open Porous Media project (OPM).
OPM is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
OPM is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with OPM. If not, see <http://www.gnu.org/licenses/>.
*/
#include <opm/core/simulator/PIDTimeStepControl.hpp>
namespace Opm
{
/// \brief constructor
/// \param tol tolerance for the relative changes of the numerical solution to be accepted
/// in one time step (default is 1e-3)
PIDTimeStepControl::PIDTimeStepControl( const double, const bool verbose )
: p0_()
, sat0_()
, tol_( tol )
, errors_( 3, tol_ )
, verbose_( verbose )
{}
/// \brief \copydoc TimeStepControlInterface::initialize
void PIDTimeStepControl::initialize( const SimulatorState& state )
{
// store current state for later time step computation
p0_ = state.pressure();
sat0_ = state.saturation();
}
/// \brief \copydoc TimeStepControlInterface::computeTimeStepSize
double PIDTimeStepControl::computeTimeStepSize( const double dt, const int /* iterations */, const SimulatorState& state ) const
{
const size_t size = p0_.size();
assert( state.pressure().size() == size );
assert( state.saturation().size() == size );
assert( sat0_.size() == size );
// compute u^n - u^n+1
for( size_t i=0; i<size; ++i )
{
p0_[ i ] -= state.pressure()[ i ];
sat0_[ i ] -= state.saturation()[ i ];
}
// compute || u^n - u^n+1 ||
const double stateOld = inner_product( p0_.begin(), p0_.end() ) +
inner_product( sat0_.begin(), sat0_.end() );
// compute || u^n+1 ||
const double stateNew = inner_product( state.pressure().begin(), state.pressure().end() ) +
inner_product( state.saturation().begin(), state.saturation().end() );
// shift errors
for( int i=0; i<2; ++i )
errors_[ i ] = errors_[i+1];
// store new error
const double error = stateOld / stateNew;
errors_[ 2 ] = error ;
if( error > tol_ )
{
// adjust dt by given tolerance
if( verbose_ )
std::cout << "Computed step size (tol): " << (dt * tol_ / error )/86400.0 << " (days)" << std::endl;
return (dt * tol_ / error );
}
else
{
// values taking from turek time stepping paper
const double kP = 0.075 ;
const double kI = 0.175 ;
const double kD = 0.01 ;
double newDt = (dt * std::pow( errors_[ 1 ] / errors_[ 2 ], kP ) *
std::pow( tol_ / errors_[ 2 ], kI ) *
std::pow( errors_[0]*errors_[0]/errors_[ 1 ]/errors_[ 2 ], kD ));
if( verbose_ )
std::cout << "Computed step size (pow): " << newDt/86400.0 << " (days)" << std::endl;
return newDt;
}
}
PIDAndIterationCountTimeStepControl::
PIDAndIterationCountTimeStepControl( const int target_iterations,
const double tol,
const bool verbose)
: BaseType( tol, verbose )
, target_iterations_( target_iterations )
{}
double PIDAndIterationCountTimeStepControl::
computeTimeStepSize( const double dt, const int iterations, const SimulatorState& state ) const
{
double dtEstimate = BaseType :: computeTimeStepSize( dt, iterations, state );
// further reduce step size if to many iterations were used
if( iterations > target_iterations_ )
{
// if iterations was the same or dts were the same, do some magic
dtEstimate *= double( target_iterations_ ) / double(iterations);
}
return dtEstimate;
}
} // end namespace Opm
#endif

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opm/core/simulator/PIDTimeStepControl.hpp Normal file
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/*
Copyright 2014 IRIS AS
This file is part of the Open Porous Media project (OPM).
OPM is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
OPM is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with OPM. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef OPM_PIDTIMESTEPCONTROL_HEADER_INCLUDED
#define OPM_PIDTIMESTEPCONTROL_HEADER_INCLUDED
#include <vector>
#include <opm/core/simulator/TimeStepControlInterface.hpp>
namespace Opm
{
///////////////////////////////////////////////////////////////////////////////////////////////////////////////
///
/// PID controller based adaptive time step control as suggested in:
/// Turek and Kuzmin. Algebraic Flux Correction III. Incompressible Flow Problems. Uni Dortmund.
///
/// See also:
/// D. Kuzmin and S.Turek. Numerical simulation of turbulent bubbly flows. Techreport Uni Dortmund. 2004
///
/// and the original article:
/// Valli, Coutinho, and Carey. Adaptive Control for Time Step Selection in Finite Element
/// Simulation of Coupled Viscous Flow and Heat Transfer. Proc of the 10th
/// International Conference on Numerical Methods in Fluids. 1998.
///
///////////////////////////////////////////////////////////////////////////////////////////////////////////////
class PIDTimeStepControl : public TimeStepControlInterface
{
public:
/// \brief constructor
/// \param tol tolerance for the relative changes of the numerical solution to be accepted
/// in one time step (default is 1e-3)
/// \param verbose if true get some output (default = false)
PIDTimeStepControl( const double tol = 1e-3, const bool verbose = false );
/// \brief \copydoc TimeStepControlInterface::initialize
void initialize( const SimulatorState& state );
/// \brief \copydoc TimeStepControlInterface::computeTimeStepSize
double computeTimeStepSize( const double dt, const int /* iterations */, const SimulatorState& state ) const;
protected:
// return inner product for given container, here std::vector
template <class Iterator>
double inner_product( Iterator it, const Iterator end ) const
{
double product = 0.0 ;
for( ; it != end; ++it )
product += ( *it * *it );
return product;
}
protected:
mutable std::vector<double> p0_;
mutable std::vector<double> sat0_;
const double tol_;
mutable std::vector< double > errors_;
const bool verbose_;
};
///////////////////////////////////////////////////////////////////////////////////////////////////////////////
///
/// PID controller based adaptive time step control as above that also takes
/// an target iteration into account.
//
///////////////////////////////////////////////////////////////////////////////////////////////////////////////
class PIDAndIterationCountTimeStepControl : public PIDTimeStepControl
{
typedef PIDTimeStepControl BaseType;
public:
/// \brief constructor
/// \param target_iterations number of desired iterations per time step
/// \param tol tolerance for the relative changes of the numerical solution to be accepted
/// in one time step (default is 1e-3)
/// \param verbose if true get some output (default = false)
PIDAndIterationCountTimeStepControl( const int target_iterations = 20,
const double tol = 1e-3,
const bool verbose = false);
/// \brief \copydoc TimeStepControlInterface::computeTimeStepSize
double computeTimeStepSize( const double dt, const int iterations, const SimulatorState& state ) const;
protected:
const int target_iterations_;
};
} // end namespace Opm
#endif

51
opm/core/simulator/TimeStepControlInterface.hpp Normal file
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@ -0,0 +1,51 @@
/*
Copyright 2014 IRIS AS
This file is part of the Open Porous Media project (OPM).
OPM is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
OPM is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with OPM. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef OPM_TIMESTEPCONTROLINTERFACE_HEADER_INCLUDED
#define OPM_TIMESTEPCONTROLINTERFACE_HEADER_INCLUDED
namespace Opm
{
///////////////////////////////////////////////////////////////////
///
/// TimeStepControlInterface
///
///////////////////////////////////////////////////////////////////
class TimeStepControlInterface
{
protected:
TimeStepControlInterface() {}
public:
/// \param state simulation state before computing update in the solver (default is empty)
virtual void initialize( const SimulatorState& state ) {}
/// compute new time step size suggestions based on the PID controller
/// \param dt time step size used in the current step
/// \param iterations number of iterations used (linear/nonlinear)
/// \param state new solution state
///
/// \return suggested time step size for the next step
virtual double computeTimeStepSize( const double dt, const int iterations, const SimulatorState& ) const = 0;
/// virtual destructor (empty)
virtual ~TimeStepControlInterface () {}
};
}
#endif