Set conductivity

I know I can insert all conductivities with a fix property global but i have too many particle types so the input line for the fix property global is too long.
so i was asking if it is possible to do so with a set command

Thanks Christoph,

I hope it is not asking too much, but could you tell me which parts of these files I have to modify? I am not an expert of programming so any help will be appriciated

the real problem is that when I have to set coefficients of restitution there are so many atom types that liggghts crushes,
a good way to go would be to be capable of setting the restitution par atom type (it is not correct but for me would be perfect)

i have attached my modified files to the post, I am sure they miss something, because even if they compile correctly, it doesn't work as I would expected (the modified property are thermal capacity and thermal conductivity)

thanks for the attention and the help

Hello Christoph,

I have a question regarding the possibility to program the conductivity and the thermal capacity as property/atom fixes and to set an additional conductivity for the anisotropic heat transport, what I did untill now was change the
fix_heat_gran_conduction.cpp:

1. first I define them in the function:

FixHeatGranCond::FixHeatGranCond(class LAMMPS *lmp, int narg, char **arg) :
FixHeatGran(lmp, narg, arg)
{
iarg_ = 5;

area_correction_flag = 0;

bool hasargs = true;
while(iarg_ < narg && hasargs)
{
hasargs = false;
if(strcmp(arg[iarg_],"area_correction") == 0) {
if (iarg_+2 > narg) error->fix_error(FLERR,this,"not enough arguments for keyword 'area_correction'");
if(strcmp(arg[iarg_+1],"yes") == 0)
area_correction_flag = 1;
else if(strcmp(arg[iarg_+1],"no") == 0)
area_correction_flag = 0;
else error->fix_error(FLERR,this,"expecting 'yes' otr 'no' after 'area_correction'");
iarg_ += 2;
hasargs = true;
} else if(strcmp(style,"heat/gran/conduction") == 0)
error->fix_error(FLERR,this,"unknown keyword");
}

fix_conductivityx = NULL;
conductivityx = NULL;
fix_conductivityz = NULL;
conductivityz = NULL;

}

2. after I tell in the programm to search for the two fix property/atom in the command line:

void FixHeatGranCond::init()
{
// initialize base class
FixHeatGran::init();

const double *Y, *nu, *Y_orig;
double expo, Yeff_ij, Yeff_orig_ij, ratio;
int max_type = pair_gran->mpg->max_type();

if (conductivityx) delete []conductivityx;

fix_conductivityx=static_cast(modify->find_fix_property("thermalConductivityx","property/atom","scalar",0,0,style));

if (conductivityz) delete []conductivityz;

fix_conductivityz=static_cast(modify->find_fix_property("thermalConductivityz","property/atom","scalar",0,0,style));

3. then

void FixHeatGranCond::updatePtrs()
{
conductivityx = fix_conductivityx->vector_atom;
conductivityz = fix_conductivityz->vector_atom;

}

4. and for last I set the thermal flux equation:

tcoix = conductivityx[i];
tcojx = conductivityx[j];
tcoiz = conductivityz[i];
tcojz = conductivityz[j];
if (tcoiz < SMALL || tcojz < SMALL) hc = 0.;
else if (x[i][2] = x[j][2]) hc =
4.*tcoiz*tcojz/(tcoiz+tcojz)*sqrt(contactArea); //this condition could be
better, but for now is all I need)
else hc = 4.*tcoix*tcojx/(tcoix+tcojx)*sqrt(contactArea);

as for the thermal capacity part:

I added these lines in fix_scalar_ transport_equation.cpp:

1.
if (fix_source==NULL){

fixarg[0]=capacity_name;
fixarg[1]="all";
fixarg[2]="property/atom";
fixarg[3]= "thermalCapacity"
fixarg[4]="scalar";
fixarg[5]="yes";
fixarg[6]="yes";
fixarg[7]="yes";
fixarg[8]="0.";
modify->add_fix(9,const_cast(fixarg));

fix_capacity=static_cast(modify->find_fix_property(capacity_name,"property/atom","scalar",0,0,style));

2. I have deleted these lines in FixScalarTransportEquation::init()

int max_type = pair_gran->mpg->max_type();

if(capacity) delete []capacity;
capacity = new double[max_type+1];

fix_capacity =
static_cast(modify->find_fix_property(capacity_name,"property/global","peratomtype",max_type,0,style));

//pre-calculate parameters for possible contact material combinations
for(int i=1;i< max_type+1; i++)
for(int j=1;jcompute_vector(i-1);
}

replaced by

fix_capacity=static_cast(modify->find_fix_property(capacity_name,"property/atom","scalar",0,0,style));
capacity = fix_capacity->vector_atom;

3. and in the end i have replaced
if(fabs(capacity) > SMALL) quantity[i] += (flux[i] + source[i]) * dt / (rmass[i]*capacity); with

if(fabs(capacity) > SMALL) quantity[i] += (flux[i] + source[i]) * dt / (rmass[i]*capacity[i]);

but it doesn't seem to work, it compiles correctly but when i try to use "fix heat/gran/conduction" it gives me a segmentation fault, any help you could give me?

Ok, thank you, I will ask