Homec4science
Diffusion lammps (lammm-master) Browse

lammps/src/USER-SPH/pair_sph_rhosum.cpp
c8a544cbaed8lammm-master

Last Change
Raw File

pair_sph_rhosum.cpp
View Options

/* ----------------------------------------------------------------------
LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
http://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 "math.h"
#include "stdlib.h"
#include "pair_sph_rhosum.h"
#include "atom.h"
#include "force.h"
#include "comm.h"
#include "neigh_list.h"
#include "neigh_request.h"
#include "memory.h"
#include "error.h"
#include "neighbor.h"
#include "update.h"
#include "domain.h"
using namespace LAMMPS_NS;
/* ---------------------------------------------------------------------- */
PairSPHRhoSum::PairSPHRhoSum(LAMMPS *lmp) : Pair(lmp)
{
restartinfo = 0;
// set comm size needed by this Pair
comm_forward = 1;
first = 1;
}
/* ---------------------------------------------------------------------- */
PairSPHRhoSum::~PairSPHRhoSum() {
if (allocated) {
memory->destroy(setflag);
memory->destroy(cutsq);
memory->destroy(cut);
}
}
/* ----------------------------------------------------------------------
init specific to this pair style
------------------------------------------------------------------------- */
void PairSPHRhoSum::init_style() {
// need a full neighbor list
int irequest = neighbor->request(this);
neighbor->requests[irequest]->half = 0;
neighbor->requests[irequest]->full = 1;
}
/* ---------------------------------------------------------------------- */
void PairSPHRhoSum::compute(int eflag, int vflag) {
int i, j, ii, jj, jnum, itype, jtype;
double xtmp, ytmp, ztmp, delx, dely, delz;
double r, rsq, imass, h, ih, ihsq;
int *jlist;
double wf;
// neighbor list variables
int inum, *ilist, *numneigh, **firstneigh;
if (eflag || vflag)
ev_setup(eflag, vflag);
else
evflag = vflag_fdotr = 0;
double **x = atom->x;
double *rho = atom->rho;
int *type = atom->type;
double *mass = atom->mass;
// check consistency of pair coefficients
if (first) {
for (i = 1; i <= atom->ntypes; i++) {
for (j = 1; i <= atom->ntypes; i++) {
if (cutsq[i][j] > 0.0) {
if (!setflag[i][i] || !setflag[j][j]) {
if (comm->me == 0) {
printf(
"SPH particle types %d and %d interact, but not all of their single particle properties are set.\n",
i, j);
}
}
}
}
}
first = 0;
}
inum = list->inum;
ilist = list->ilist;
numneigh = list->numneigh;
firstneigh = list->firstneigh;
// recompute density
// we use a full neighborlist here
if (nstep != 0) {
if ((update->ntimestep % nstep) == 0) {
// initialize density with self-contribution,
for (ii = 0; ii < inum; ii++) {
i = ilist[ii];
itype = type[i];
imass = mass[itype];
h = cut[itype][itype];
if (domain->dimension == 3) {
/*
// Lucy kernel, 3d
wf = 2.0889086280811262819e0 / (h * h * h);
*/
// quadric kernel, 3d
wf = 2.1541870227086614782 / (h * h * h);
} else {
/*
// Lucy kernel, 2d
wf = 1.5915494309189533576e0 / (h * h);
*/
// quadric kernel, 2d
wf = 1.5915494309189533576e0 / (h * h);
}
rho[i] = imass * wf;
}
// add density at each atom via kernel function overlap
for (ii = 0; ii < inum; ii++) {
i = ilist[ii];
xtmp = x[i][0];
ytmp = x[i][1];
ztmp = x[i][2];
itype = type[i];
jlist = firstneigh[i];
jnum = numneigh[i];
for (jj = 0; jj < jnum; jj++) {
j = jlist[jj];
j &= NEIGHMASK;
jtype = type[j];
delx = xtmp - x[j][0];
dely = ytmp - x[j][1];
delz = ztmp - x[j][2];
rsq = delx * delx + dely * dely + delz * delz;
if (rsq < cutsq[itype][jtype]) {
h = cut[itype][jtype];
ih = 1.0 / h;
ihsq = ih * ih;
if (domain->dimension == 3) {
/*
// Lucy kernel, 3d
r = sqrt(rsq);
wf = (h - r) * ihsq;
wf = 2.0889086280811262819e0 * (h + 3. * r) * wf * wf * wf * ih;
*/
// quadric kernel, 3d
wf = 1.0 - rsq * ihsq;
wf = wf * wf;
wf = wf * wf;
wf = 2.1541870227086614782e0 * wf * ihsq * ih;
} else {
// Lucy kernel, 2d
//r = sqrt(rsq);
//wf = (h - r) * ihsq;
//wf = 1.5915494309189533576e0 * (h + 3. * r) * wf * wf * wf;
// quadric kernel, 2d
wf = 1.0 - rsq * ihsq;
wf = wf * wf;
wf = wf * wf;
wf = 1.5915494309189533576e0 * wf * ihsq;
}
rho[i] += mass[jtype] * wf;
}
}
}
}
}
// communicate densities
comm->forward_comm_pair(this);
}
/* ----------------------------------------------------------------------
allocate all arrays
------------------------------------------------------------------------- */
void PairSPHRhoSum::allocate() {
allocated = 1;
int n = atom->ntypes;
memory->create(setflag, n + 1, n + 1, "pair:setflag");
for (int i = 1; i <= n; i++)
for (int j = i; j <= n; j++)
setflag[i][j] = 0;
memory->create(cutsq, n + 1, n + 1, "pair:cutsq");
memory->create(cut, n + 1, n + 1, "pair:cut");
}
/* ----------------------------------------------------------------------
global settings
------------------------------------------------------------------------- */
void PairSPHRhoSum::settings(int narg, char **arg) {
if (narg != 1)
error->all(FLERR,
"Illegal number of setting arguments for pair_style sph/rhosum");
nstep = force->inumeric(arg[0]);
}
/* ----------------------------------------------------------------------
set coeffs for one or more type pairs
------------------------------------------------------------------------- */
void PairSPHRhoSum::coeff(int narg, char **arg) {
if (narg != 3)
error->all(FLERR,"Incorrect number of args for sph/rhosum coefficients");
if (!allocated)
allocate();
int ilo, ihi, jlo, jhi;
force->bounds(arg[0], atom->ntypes, ilo, ihi);
force->bounds(arg[1], atom->ntypes, jlo, jhi);
double cut_one = force->numeric(arg[2]);
int count = 0;
for (int i = ilo; i <= ihi; i++) {
for (int j = MAX(jlo,i); j <= jhi; j++) {
//printf("setting cut[%d][%d] = %f\n", i, j, cut_one);
cut[i][j] = cut_one;
setflag[i][j] = 1;
count++;
}
}
if (count == 0)
error->all(FLERR,"Incorrect args for pair coefficients");
}
/* ----------------------------------------------------------------------
init for one type pair i,j and corresponding j,i
------------------------------------------------------------------------- */
double PairSPHRhoSum::init_one(int i, int j) {
if (setflag[i][j] == 0) {
error->all(FLERR,"All pair sph/rhosum coeffs are not set");
}
cut[j][i] = cut[i][j];
return cut[i][j];
}
/* ---------------------------------------------------------------------- */
double PairSPHRhoSum::single(int i, int j, int itype, int jtype, double rsq,
double factor_coul, double factor_lj, double &fforce) {
fforce = 0.0;
return 0.0;
}
/* ---------------------------------------------------------------------- */
int PairSPHRhoSum::pack_comm(int n, int *list, double *buf, int pbc_flag,
int *pbc) {
int i, j, m;
double *rho = atom->rho;
m = 0;
for (i = 0; i < n; i++) {
j = list[i];
buf[m++] = rho[j];
}
return 1;
}
/* ---------------------------------------------------------------------- */
void PairSPHRhoSum::unpack_comm(int n, int first, double *buf) {
int i, m, last;
double *rho = atom->rho;
m = 0;
last = first + n;
for (i = first; i < last; i++)
rho[i] = buf[m++];
}
c4science · Help