/* ---------------------------------------------------------------------- LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator https://lammps.sandia.gov/, Sandia National Laboratories Steve Plimpton, sjplimp@sandia.gov Copyright (2003) Sandia Corporation. Under the terms of Contract DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government retains certain rights in this software. This software is distributed under the GNU General Public License. See the README file in the top-level LAMMPS directory. ------------------------------------------------------------------------- */ #include "fix_sph.h" #include "atom.h" #include "force.h" #include "update.h" #include "error.h" #include "comm.h" using namespace LAMMPS_NS; using namespace FixConst; /* ---------------------------------------------------------------------- */ FixSPH::FixSPH(LAMMPS *lmp, int narg, char **arg) : Fix(lmp, narg, arg) { if ((atom->esph_flag != 1) || (atom->rho_flag != 1)) error->all(FLERR, "Fix sph command requires atom_style with both energy and density"); if (narg != 3) error->all(FLERR,"Illegal number of arguments for fix sph command"); time_integrate = 1; } /* ---------------------------------------------------------------------- */ int FixSPH::setmask() { int mask = 0; mask |= INITIAL_INTEGRATE; mask |= FINAL_INTEGRATE; //mask |= PRE_FORCE; // mask |= POST_FORCE; return mask; } /* ---------------------------------------------------------------------- */ void FixSPH::init() { dtv = update->dt; dtf = 0.5 * update->dt * force->ftm2v; } /* ---------------------------------------------------------------------- */ void FixSPH::setup_pre_force(int /*vflag*/) { // set vest equal to v double **v = atom->v; double **vest = atom->vest; int *mask = atom->mask; int nlocal = atom->nlocal; if (igroup == atom->firstgroup) nlocal = atom->nfirst; for (int i = 0; i < nlocal; i++) { if (mask[i] & groupbit) { vest[i][0] = v[i][0]; vest[i][1] = v[i][1]; vest[i][2] = v[i][2]; } } } /* ---------------------------------------------------------------------- allow for both per-type and per-atom mass ------------------------------------------------------------------------- */ void FixSPH::initial_integrate(int /*vflag*/) { // update v and x and rho and e of atoms in group double **gradv = atom->gradv; double *gammadot = atom->gammadot; double *fintx = atom->fintx; double *finty = atom->finty; double **x = atom->x; double **v = atom->v; double **f = atom->f; double **vest = atom->vest; double *rho = atom->rho; double *drho = atom->drho; double *esph = atom->esph; double *desph = atom->desph; double *mass = atom->mass; double *rmass = atom->rmass; int rmass_flag = atom->rmass_flag; int *type = atom->type; int *mask = atom->mask; int nlocal = atom->nlocal; int i; double dtfm; if (igroup == atom->firstgroup) nlocal = atom->nfirst; for (i = 0; i < nlocal; i++) { if (mask[i] & groupbit) { if (rmass_flag) { dtfm = dtf / rmass[i]; } else { dtfm = dtf / mass[type[i]]; } gradv[i][0] = 0.0; gradv[i][1] = 0.0; gradv[i][2] = 0.0; gradv[i][3] = 0.0; gradv[i][4] = 0.0; gradv[i][5] = 0.0; gradv[i][6] = 0.0; gradv[i][7] = 0.0; gradv[i][8] = 0.0; fintx[i] = 1e-10; finty[i] = 1e-10; esph[i] += dtf * desph[i]; // half-step update of particle internal energy rho[i] += dtf * drho[i]; // ... and density // extrapolate velocity for use with velocity-dependent potentials, e.g. SPH vest[i][0] = v[i][0] + 2.0 * dtfm * f[i][0]; vest[i][1] = v[i][1] + 2.0 * dtfm * f[i][1]; vest[i][2] = v[i][2] + 2.0 * dtfm * f[i][2]; v[i][0] += dtfm * f[i][0]; v[i][1] += dtfm * f[i][1]; v[i][2] += dtfm * f[i][2]; x[i][0] += dtv * v[i][0]; x[i][1] += dtv * v[i][1]; x[i][2] += dtv * v[i][2]; } } } /* ---------------------------------------------------------------------- */ //void FixSPH::pre_force(int /*vflag*/) /* { double **gradv = atom->gradv; double *gammadot = atom->gammadot; int *mask = atom->mask; int nlocal = atom->nlocal; int *type = atom->type; if (igroup == atom->firstgroup) nlocal = atom->nfirst; for (int i = 0; i < nlocal; i++) { if (mask[i] & groupbit) { gammadot[i] = sqrt(2 * ( gradv[i][0]*gradv[i][0] + gradv[i][1]*gradv[i][1] + gradv[i][2]*gradv[i][2] + 2 * ( 0.5*(gradv[i][3] + gradv[i][6]) * 0.5*(gradv[i][3] + gradv[i][6]) + 0.5*(gradv[i][4] + gradv[i][7]) * 0.5*(gradv[i][4] + gradv[i][7]) + 0.5*(gradv[i][5] + gradv[i][8]) * 0.5*(gradv[i][5] + gradv[i][8]) ) )); //if (type[i] == 1) { //printf("gammadot[%d] = %f\n", i, gammadot[i]); //} } } } */ /* ---------------------------------------------------------------------- */ void FixSPH::final_integrate() { // update v, rho, and e of atoms in group double **gradv = atom->gradv; double *gammadot = atom->gammadot; double *fintx = atom->fintx; double *finty = atom->finty; double **v = atom->v; double **f = atom->f; double *esph = atom->esph; double *desph = atom->desph; double *rho = atom->rho; double *drho = atom->drho; int *type = atom->type; int *mask = atom->mask; double *mass = atom->mass; int nlocal = atom->nlocal; if (igroup == atom->firstgroup) nlocal = atom->nfirst; double dtfm; double *rmass = atom->rmass; int rmass_flag = atom->rmass_flag; for (int i = 0; i < nlocal; i++) { if (mask[i] & groupbit) { if (rmass_flag) { dtfm = dtf / rmass[i]; } else { dtfm = dtf / mass[type[i]]; } v[i][0] += dtfm * f[i][0]; v[i][1] += dtfm * f[i][1]; v[i][2] += dtfm * f[i][2]; esph[i] += dtf * desph[i]; rho[i] += dtf * drho[i]; //Only 2d to test // double trace; // trace = gradv[i][0]+gradv[i][1];//+gradv[i][0] // stfluid[i][0] = 0;//(2*gradv[i][0]+trace/2); // stfluid[i][1] = 0;//(2*gradv[i][1]+trace/2); // stfluid[i][2] = 0.0;//(gradv[i][2]-trace/2); // stfluid[i][3] = (gradv[i][3]+gradv[i][6]); // stfluid[i][4] = 0.0;//0.5*(gradv[i][4]+gradv[i][7]); // stfluid[i][5] = 0.0;//0.5*(gradv[i][5]+gradv[i][8]); // ASE added the calculation of gamma_dot as the square of the sum of the gradient plus its transpose (Frobenius norm) gammadot[i] = sqrt(2 * ( gradv[i][0]*gradv[i][0] + gradv[i][1]*gradv[i][1] + gradv[i][2]*gradv[i][2] + 2 * ( 0.5*(gradv[i][3] + gradv[i][6]) * 0.5*(gradv[i][3] + gradv[i][6]) + 0.5*(gradv[i][4] + gradv[i][7]) * 0.5*(gradv[i][4] + gradv[i][7]) + 0.5*(gradv[i][5] + gradv[i][8]) * 0.5*(gradv[i][5] + gradv[i][8]) ) )); } } } /* ---------------------------------------------------------------------- */ void FixSPH::reset_dt() { dtv = update->dt; dtf = 0.5 * update->dt * force->ftm2v; }