[payam_IUST]

Hi
I am using steady particle tracking and then generate step by step file to see positions of particle at evrey time step.unfortunately the time step that fluent considers is very small(ebout 1e-6) and I want to change it(to about 1e-2),but however I change length scale or step length,the time step does not chang effectively,I even examined this udf to change time step :


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

DEFINE_DPM_TIMESTEP(PAYAM,p,dt)
{
return 0.1;
return dt
}

but nothing changes!
Anyone can help me?

[Andrej]

Probably you can not make time step more , then
length of Cell divided by the Velocity of the particle in cell. CFL Number in Cell can not be more then 1.0.