Problem with DPM
 

Hi

I have a project regarding particles dispersion. Recently, I found something strange in Fluent DPM. I did a test by injecting a particle at constant speed and zero drag coefficient. So, the particle should reach the outlet by time=length/speed. But it is not, the result depends on the time step used.

The attachment is the result and the UDF I used for testing. I found when particles cross a cell, it jumps in the position. This problem results in the transit time gets shorten non-physically. And it only happens to particles flow in the inflation layers where the cell is really thin.

Does anyone know why this is happening?

Any commend is appreciated.