[zhang.limin]

Originally Posted by lauripar

I checked my SDK and it is v7.1. I have windows 7 and 64 bit system, could some my problems be related to that?

Microsoft windows .net framework v2.0 should be work

[JSoares]

Hello everyone

Since the source (sandia uv) is the same, i´m wondering if anyone can explain to me the injection code?

I was able to compile the udf whith sucess but i´m with doubts on creating the injection code file, because i don´t understand the parameters.

My case is 2D what means:

! plane: desired plane for injection points (xy, xz, yz) - My case is 2D and the plane of the flow is xy, shold i select xz. Or this could be a problem?

i don´t know what this coordinates are?

! coord: axial coordinate of the plane (m)
! coord1: 1st coordinate of injection-plane centroid (m)
! coord2: 2nd coordinate of injection-plane centroid (m)

Thank you and if anyone needs help with the udf for fluent 12.1 contact me

[zhang.limin]

x y z . u v w, temperature, diameter, density, id

[rubis]

hi all ,
i have this udf but i can'nt display it in fluent ;

#include <udf.h>
DEFINE_PROPERTY (dyn_surf_tension, cell, thread)
{
real dst;
real t=CURRENT_TIME;
dst=141121*pow(t,5) - 38978*pow(t,4) + 3817.5*pow(t,3) - 148.84*pow(t,2) +
1.3033*pow(t,1) + 0.071;
return dst;

thank you

[JSoares]

Hello everyone

Just two questions: does it matters the material used for particles? And should i select the uv interaction on dpm model?

Or does sandia files regards this problem.

Real thanks

[zhang.limin]

it is massless particle type . from file injection.

[zhang.limin]

just particle tracking in dpm

[JSoares]

Thanks. I´m not using the injections from the file but a group injection cause i don´t want a circular injection, but the principle is the same.

Another question: anyone using this tipe of simulation on transient state? I´m with doubts if there is any equation to determine the step length factor?

real thanks

[zhang.limin]

STEP LENGTH FACTOR is as better as smaller depend your mesh size, usually the particle travel one mesh one step, and if you can manage 10+ step in one mesh cell should be much better

[JSoares]

Thanks zhang.limin

I didnt quite understand the last answer. I´ve a structured mesh but the size of each cell is differente since i use a progression nearby the cylinder (UV lamp) because of wall behaviour.

My domain is 1.08 meters in the flow direction, and i have 270 cells in the same direction. But the smallest cell near the wall (cylinder) have aproximated 1.54e-4 meters of length.

In this case what is the max STEP LENGTH FACTOR or even the specified length scale that i should use in order to a particle travel one cell in one timestep.

One more time real thanks

[JSoares]

Hello everyone

I´ve one question: How do you define red constants A and B? My problem is that i only have acess at this time to numerical values(fluent).

I´m using a model used for numerical solutions where:

RED=1/k*ln((1/number of particl.)*sum(exp(-k*Di))
Ni/No=exp(-k*Di)

Where Di is the dose of each particle and k is a coefficient of the first order of inactivation of a microbe.

Anyone have other solutions or sugestions?

Thanks

[JSoares]

Hello everyone.

Regarding Sandia UDf, it´s possible to use this in unsteady dpm tracking?
I have a problem with this UDF using unsteady particle tracking, because the scalar is updated to a new value and will not retain the last. I want to measure the total U.V. dose in each particle on the output boundary, but I only get the last value of UV dose, and not the total.
I´m a beginner user to UDF but there is any way to change this, to retain the values of UV dose each dpm time step?

/************************************************** *********************/
/* UDF for computing the UV dosage along a particle trajectory */
/************************************************** *********************/

#include "udf.h"
#include "dpm.h"
#include "sg_disco.h"

#define fileuv "output.dpm"
#define C_DO(c,t)C_STORAGE_R_XV(c,t,SV_DO_IRRAD,0)

static real uv_intensity_0;
static real x0, y00, z0;

FILE *fuv;

DEFINE_DPM_SCALAR_UPDATE(uv_dosage, cell, thread, initialize, p)
{
cphase_state_t *c = &(p->cphase);
if (initialize)
{
p->user[0] = 0.;
uv_intensity_0 = C_DO(cell,thread);
x0=p->state.pos[0];
y00=p->state.pos[1];
z0=p->state.pos[2];
}

else
{
p->user[0] += P_DT(p) * .5 * (uv_intensity_0 + C_DO(cell,thread));
uv_intensity_0 = C_DO(cell,thread);
}
}

DEFINE_DPM_OUTPUT(uv_output, header, fp, p, thread, plane)
{

char name[100];


if (header)
{
fuv = fopen(fileuv,"w");
if (NNULLP(thread))
{
fprintf(fuv,"(%s %d)\n",thread->head->dpm_summary.sort_file_name,14);
}
else
fprintf(fuv,"(%s %d)\n",plane->sort_file_name,14);
fprintf(fuv,"(%10s %10s %10s %10s %10s %10s %10s"
" %10s %10s %10s %10s %10s %10s %10s %s)\n",
"X0","Y0","Z0",
"X","Y","Z","U","V","W","diameter","T","mass-flow",
"time","UV-Dosage","name");
fclose(fuv);
}
else
{
fuv = fopen(fileuv,"a");
sprintf(name,"%s:%d",p->injection->name,p->part_id);
fprintf(fuv,
"((%10.6g %10.6g %10.6g %10.6g %10.6g %10.6g "
"%10.6g %10.6g %10.6g %10.6g %10.6g %10.6g %10.6g %10.6g) %s)\n",
x0,y00,z0,
p->state.pos[0], p->state.pos[1], p->state.pos[2],
p->state.V[0], p->state.V[1], p->state.V[2],
p->state.diam, p->state.temp, p->flow_rate, p->state.time,
p->user[0], name);
fclose(fuv);
}
}