[imanzeydabadi]

Hi
I simulated a cyclone in fluent.now I'm tracking particle in unsteady method.
when fluent go to dpm tracing, print "epsilon too small epsilon too small..."
can any body help me???

[pakk]

I just had the same problem.
For me it is in steady-state, laminar flow (so no k-epsilon model used).
I have tried changing the tolerance in the accuracy control of the dpm model, but the same error message keeps coming up.

The solution in my case: I looked at the injection file that I used, and I found out that I made a mistake before, and had given the particles an initial velocity of 1e22 m/s. After fixing that mistake, the particles started with a more realistic velocity, and the "epsilon too small" error disappeared.

[GM_XIII]

Hi guys,

I am experiencing the same problem, it is also a laminar flow so I don't really understand what it is referring to epsilon (do someone know?). I reviewed my BCs and nothing seem to be wrong. The particles are accelerated by a volumetric force given by an UDF, maybe this can be the source of the problem, I am testing it. Any hint or idea is welcomed.

Thanks in advance

[SJSW]

Hi~
The same error appeared when using DPM and LES.

It said:

"
DPM Iteration ....
epsilon too small
Internal error at line 16140 in file '..\..\src\dpm_path.c' on Node 1.
epsilon too small
Internal error at line 16140 in file '..\..\src\dpm_path.c' on Node 0.
epsilon too small
Internal error at line 16140 in file '..\..\src\dpm_path.c' on Node 1.
epsilon too small
Internal error at line 16140 in file '..\..\src\dpm_path.c' on Node 2.
number tracked = 1, escaped = 0, aborted = 0, trapped = 0, evaporated = 0, incomplete = 0, incomplete_parallel = 0
Parallel particle tracking concurrency: 33%
"

I think that if the error is related to dpm path?
and another question is: what is the meaning of "Parallel particle tracking concurrency: 33%" ?

Can anyone kindly help?
Thank you!

[claudy.daniel]

try to increase the turbulent dissipation rate in under-relaxation factor