[dust_2]

Hi, all! I wrote a DPM UDF for fluent 6.3.26. But I don't know how to edit it to parallel UDF(1CPU 8cores ). Can anyone help me, plz?

By the way, could this udf run on Liunx system?


#include "udf.h"
#include "dpm.h"
#include "math.h"
#include "time.h"
#include "stdio.h"
static int n=0;


double integral(double s) // to generate a parabolic particle distribution
{
double a=0.0,b=5.0,mid=2.5,y=-0.004*mid*mid*mid+0.3*mid;
for(;fabs(s-y)>1e-6; )
{
if(s>y)
{
a=mid;
mid=(mid+b)/2.0;
}
else
{
b=mid;
mid=(a+mid)/2.0;
}
y=-0.004*mid*mid*mid+0.3*mid;
}

return mid;
}

DEFINE_DPM_INJECTION_INIT(init_particles,I)
{

Particle *p;
FILE *fp;
real xm[ND_ND];
double R=0.0, x=0.0, y=0.0, an=0.0,k=0.0;
if(n==0)srand((unsigned)time( NULL ));
k=rand()/(double)(RAND_MAX);
R=integral(k);
an=rand()/(double)(RAND_MAX)*2*3.1415926;
x=R*sin(an)/200.0;
y=R*cos(an)/200.0;
Message ("\n n=%d, k=%f\n",n, k);
n++;
p=I->p_init;
P_POS(p)[0]=x;
P_POS(p)[1]=y;
P_POS(p)[2]=0.0;
Message ("particle position x=%f, y=%f\n", P_POS(p)[0],P_POS(p)[1]);
xm[0]=P_POS(p)[0];
xm[1]=P_POS(p)[1];
xm[2]=P_POS(p)[2];
P_DIAM(p)=5e-6;
P_RHO(p)=1000;
P_MASS(p)=P_RHO(p)*M_PI*pow(P_DIAM(p),3.0)/6.0;
P_FLOW_RATE(p)=P_MASS(p)/0.06;
fp=fopen("e:\\test\\pa.txt","at");
fprintf(fp,"%f %f %f\n",R,xm[0],xm[1]);
fclose(fp);

}

[johnwinter]

for parallel code you should keep
#if !RP_HOST
#endif
and
#if ! RP_NODE
#endif

has to be kept at appropriate places in the code. See UDF manual for more details

[dust_2]

Originally Posted by johnwinter

for parallel code you should keep
#if !RP_HOST
#endif
and
#if ! RP_NODE
#endif

has to be kept at appropriate places in the code. See UDF manual for more details

Thanks for your reply. But I just don't know where to put them. The manual only has one page mentioned about the paralleliztion of DPM model. And it mainly talks about message output.

[johnwinter]

HI i am not an expert, based on my knowledge i have corrected your code below

#include "udf.h"
#include "dpm.h"
#include "math.h"
#include "time.h"
#include "stdio.h"
static int n=0;


double integral(double s) // to generate a parabolic particle distribution
{
#if !RP_HOST

double a=0.0,b=5.0,mid=2.5,y=-0.004*mid*mid*mid+0.3*mid;
for(;fabs(s-y)>1e-6; )
{
if(s>y)
{
a=mid;
mid=(mid+b)/2.0;
}
else
{
b=mid;
mid=(a+mid)/2.0;
}
y=-0.004*mid*mid*mid+0.3*mid;
}

return mid;
#end if
}

DEFINE_DPM_INJECTION_INIT(init_particles,I)
{
#if !RP_HOST

Particle *p;
FILE *fp;
real xm[ND_ND];
double R=0.0, x=0.0, y=0.0, an=0.0,k=0.0;
if(n==0)srand((unsigned)time( NULL ));
k=rand()/(double)(RAND_MAX);
R=integral(k);
an=rand()/(double)(RAND_MAX)*2*3.1415926;
x=R*sin(an)/200.0;
y=R*cos(an)/200.0;
// Message ("\n n=%d, k=%f\n",n, k);
n++;
p=I->p_init;
P_POS(p)[0]=x;
P_POS(p)[1]=y;
P_POS(p)[2]=0.0;
//Message ("particle position x=%f, y=%f\n", P_POS(p)[0],P_POS(p)[1]);
xm[0]=P_POS(p)[0];
xm[1]=P_POS(p)[1];
xm[2]=P_POS(p)[2];
P_DIAM(p)=5e-6;
P_RHO(p)=1000;
P_MASS(p)=P_RHO(p)*M_PI*pow(P_DIAM(p),3.0)/6.0;
P_FLOW_RATE(p)=P_MASS(p)/0.06;
#endif
node_to_host_real_3(R, xm[0],xm[1]);
#if !RP_NODE

fp=fopen("e:\\test\\pa.txt","at");
fprintf(fp,"%f %f %f\n",R,xm[0],xm[1]);
fclose(fp);
#endif
}

you may need to change some more look at carefully and change. all the best

[dust_2]

Originally Posted by johnwinter

HI i am not an expert, based on my knowledge i have corrected your code below

#include "udf.h"
#include "dpm.h"
#include "math.h"
#include "time.h"
#include "stdio.h"
static int n=0;


double integral(double s) // to generate a parabolic particle distribution
{
#if !RP_HOST

double a=0.0,b=5.0,mid=2.5,y=-0.004*mid*mid*mid+0.3*mid;
for(;fabs(s-y)>1e-6; )
{
if(s>y)
{
a=mid;
mid=(mid+b)/2.0;
}
else
{
b=mid;
mid=(a+mid)/2.0;
}
y=-0.004*mid*mid*mid+0.3*mid;
}

return mid;
#end if
}

DEFINE_DPM_INJECTION_INIT(init_particles,I)
{
#if !RP_HOST

Particle *p;
FILE *fp;
real xm[ND_ND];
double R=0.0, x=0.0, y=0.0, an=0.0,k=0.0;
if(n==0)srand((unsigned)time( NULL ));
k=rand()/(double)(RAND_MAX);
R=integral(k);
an=rand()/(double)(RAND_MAX)*2*3.1415926;
x=R*sin(an)/200.0;
y=R*cos(an)/200.0;
// Message ("\n n=%d, k=%f\n",n, k);
n++;
p=I->p_init;
P_POS(p)[0]=x;
P_POS(p)[1]=y;
P_POS(p)[2]=0.0;
//Message ("particle position x=%f, y=%f\n", P_POS(p)[0],P_POS(p)[1]);
xm[0]=P_POS(p)[0];
xm[1]=P_POS(p)[1];
xm[2]=P_POS(p)[2];
P_DIAM(p)=5e-6;
P_RHO(p)=1000;
P_MASS(p)=P_RHO(p)*M_PI*pow(P_DIAM(p),3.0)/6.0;
P_FLOW_RATE(p)=P_MASS(p)/0.06;
#endif
node_to_host_real_3(R, xm[0],xm[1]);
#if !RP_NODE

fp=fopen("e:\\test\\pa.txt","at");
fprintf(fp,"%f %f %f\n",R,xm[0],xm[1]);
fclose(fp);
#endif
}

you may need to change some more look at carefully and change. all the best

WOW! Thanks a lot! I'll try it.