Line data    Source code

       1             : // Copyright (C) 2015 Technische Universitaet Muenchen
       2             : // This file is part of the Mamico project. For conditions of distribution
       3             : // and use, please see the copyright notice in Mamico's main folder, or at
       4             : // www5.in.tum.de/mamico
       5             : #ifndef _MOLECULARDYNAMICS_COUPLING_CELLMAPPINGS_SETTEMPERATUREMAPPING_H_
       6             : #define _MOLECULARDYNAMICS_COUPLING_CELLMAPPINGS_SETTEMPERATUREMAPPING_H_
       7             : 
       8             : #include "coupling/interface/MDSolverInterface.h"
       9             : #include "coupling/interface/Molecule.h"
      10             : #include <cmath>
      11             : #include <iostream>
      12             : 
      13             : namespace coupling {
      14             : namespace cellmappings {
      15             : template <class LinkedCell, unsigned int dim> class SetTemperatureMapping;
      16             : }
      17             : } // namespace coupling
      18             : 
      19             : /**
      20             :  *      @brief This class sets a certain temperature over several linked cells.
      21             :  *      @tparam LinkedCell cell type
      22             :  *      @tparam dim Number of dimensions; it can be 1, 2 or 3
      23             :  *  @author Philipp Neumann
      24             :  */
      25             : template <class LinkedCell, unsigned int dim> class coupling::cellmappings::SetTemperatureMapping {
      26             : public:
      27             :   /** Constructor: obtains the old temperature over the region of interest.
      28             :    *Besides, obtains the new temperature.
      29             :    *    @param oldTemperature
      30             :    *    @param newTemperature
      31             :    *    @param meanVelocity
      32             :    *    @param mdSolverInterface
      33             :    */
      34           0 :   SetTemperatureMapping(const double& oldTemperature, const double& newTemperature, const tarch::la::Vector<dim, double>& meanVelocity,
      35             :                         coupling::interface::MDSolverInterface<LinkedCell, dim>* const mdSolverInterface)
      36           0 :       : _mdSolverInterface(mdSolverInterface), _factor(getScalingFactor(oldTemperature, newTemperature)), _meanVelocity(meanVelocity) {}
      37             : 
      38             :   /** Destructor */
      39           0 :   ~SetTemperatureMapping() {}
      40             : 
      41             :   /** empty function
      42             :    */
      43             :   void beginCellIteration() {}
      44             : 
      45             :   /** empty function
      46             :    */
      47             :   void endCellIteration() {}
      48             : 
      49             :   /** applies a certain temperature over several linked cells, by changing the
      50             :    *velocity (velocity fluctuation).
      51             :    *    @param cell
      52             :    */
      53           0 :   void handleCell(LinkedCell& cell) {
      54           0 :     coupling::interface::MoleculeIterator<LinkedCell, dim>* it = _mdSolverInterface->getMoleculeIterator(cell);
      55           0 :     it->begin();
      56           0 :     while (it->continueIteration()) {
      57           0 :       coupling::interface::Molecule<dim>& wrapper(it->get());
      58           0 :       tarch::la::Vector<dim, double> velocity = wrapper.getVelocity();
      59             :       // scale velocity
      60           0 :       velocity = _meanVelocity + _factor * (velocity - _meanVelocity);
      61           0 :       wrapper.setVelocity(velocity);
      62           0 :       it->next();
      63             :     }
      64           0 :     delete it;
      65           0 :   }
      66             : 
      67             : private:
      68             :   /** calculates the scaling factor between the old and new temperatures.
      69             :    *    @param oldTemperature
      70             :    *    @param newTemperature
      71             :    *    @return newTemperature
      72             :    *    @remark only allow re-scaling if the original temperature was not zero
      73             :    *(can happen in empty cells that just became populated)
      74             :    */
      75           0 :   double getScalingFactor(const double& oldTemperature, const double& newTemperature) const {
      76             : 
      77           0 :     if (oldTemperature != 0.0) {
      78           0 :       return sqrt(newTemperature / oldTemperature);
      79             :     } else {
      80             :       return 1.0;
      81             :     }
      82             :   }
      83             : 
      84             :   coupling::interface::MDSolverInterface<LinkedCell, dim>* const _mdSolverInterface;
      85             :   const double _factor;
      86             :   const tarch::la::Vector<dim, double> _meanVelocity;
      87             : };
      88             : #endif // _MOLECULARDYNAMICS_COUPLING_CELLMAPPINGS_SETTEMPERATUREMAPPING_H_