147 lines
3.9 KiB
C++
147 lines
3.9 KiB
C++
/* ----------------------------------------------------------------------
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LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
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http://lammps.sandia.gov, Sandia National Laboratories
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Steve Plimpton, sjplimp@sandia.gov
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Copyright (2003) Sandia Corporation. Under the terms of Contract
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DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government retains
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certain rights in this software. This software is distributed under
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the GNU General Public License.
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See the README file in the top-level LAMMPS directory.
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------------------------------------------------------------------------- */
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/* ----------------------------------------------------------------------
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Contributing authors: Frances Mackay, Santtu Ollila, Colin Denniston (UWO)
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------------------------------------------------------------------------- */
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#include <cmath>
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#include <cstdlib>
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#include <cstring>
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#include "fix_lb_viscous.h"
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#include "atom.h"
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#include "update.h"
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#include "respa.h"
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#include "error.h"
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#include "fix_lb_fluid.h"
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#include "modify.h"
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#include "group.h"
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using namespace LAMMPS_NS;
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using namespace FixConst;
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/* ---------------------------------------------------------------------- */
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FixLbViscous::FixLbViscous(LAMMPS *lmp, int narg, char **arg) :
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Fix(lmp, narg, arg)
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{
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if (narg < 3) error->all(FLERR,"Illegal fix lb/viscous command");
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int groupbit_lb_fluid = 0;
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for(int ifix=0; ifix<modify->nfix; ifix++)
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if(strcmp(modify->fix[ifix]->style,"lb/fluid")==0){
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fix_lb_fluid = (FixLbFluid *)modify->fix[ifix];
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groupbit_lb_fluid = group->bitmask[modify->fix[ifix]->igroup];
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}
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if(groupbit_lb_fluid == 0)
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error->all(FLERR,"the lb/fluid fix must also be used if using the lb/viscous fix");
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int *mask = atom->mask;
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int nlocal = atom->nlocal;
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for(int j=0; j<nlocal; j++){
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if((mask[j] & groupbit) && !(mask[j] & groupbit_lb_fluid))
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error->one(FLERR,"to apply a fluid force onto an atom, the lb/fluid fix must be used for that atom.");
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}
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}
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/* ---------------------------------------------------------------------- */
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FixLbViscous::~FixLbViscous()
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{
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}
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/* ---------------------------------------------------------------------- */
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int FixLbViscous::setmask()
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{
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int mask = 0;
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mask |= POST_FORCE;
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mask |= POST_FORCE_RESPA;
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mask |= MIN_POST_FORCE;
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return mask;
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}
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/* ---------------------------------------------------------------------- */
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void FixLbViscous::init()
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{
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if (strcmp(update->integrate_style,"respa") == 0)
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nlevels_respa = ((Respa *) update->integrate)->nlevels;
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}
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/* ---------------------------------------------------------------------- */
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void FixLbViscous::setup(int vflag)
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{
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if (strstr(update->integrate_style,"verlet") != NULL)
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post_force(vflag);
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else {
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((Respa *) update->integrate)->copy_flevel_f(nlevels_respa-1);
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post_force_respa(vflag,nlevels_respa-1,0);
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((Respa *) update->integrate)->copy_f_flevel(nlevels_respa-1);
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}
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}
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/* ---------------------------------------------------------------------- */
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void FixLbViscous::min_setup(int vflag)
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{
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post_force(vflag);
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}
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/* ---------------------------------------------------------------------- */
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void FixLbViscous::post_force(int vflag)
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{
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// apply drag force to atoms in group
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// direction is opposed to velocity vector
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// magnitude depends on atom type
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double **f = atom->f;
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int *mask = atom->mask;
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int nlocal = atom->nlocal;
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double **hydroF = fix_lb_fluid->hydroF;
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for (int i = 0; i < nlocal; i++)
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if (mask[i] & groupbit) {
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f[i][0] += hydroF[i][0];
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f[i][1] += hydroF[i][1];
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f[i][2] += hydroF[i][2];
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}
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}
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/* ---------------------------------------------------------------------- */
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void FixLbViscous::post_force_respa(int vflag, int ilevel, int iloop)
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{
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if (ilevel == nlevels_respa-1) post_force(vflag);
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}
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/* ---------------------------------------------------------------------- */
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void FixLbViscous::min_post_force(int vflag)
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{
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post_force(vflag);
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}
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