[richard ben]

Hello all,

I'm using the DPM model in fluent. There are some particles that are incomplete while doing particle tracking. I checked the particle trajectory and found that some particles just disappeared in the middle of the pipe. I just want to know how does fluent handle these particles and how does fluent decide when to stop tracking these particles?

BTW, it's one-way coupling. I released only 10 particles, 4/5 escaped, the rest were incomplete. I increased the max number of steps and it did not help.

Thanks
Richard

[pakk]

Fluent stops when the maximum number of time steps is reached. The default value for that is 500. You say you increased it, but did you increase it enough?

And make sure that your 'incomplete' particles don't end up in zone where the flow has zero velocity. In that case, they can stay there indefinitely, and will never leave your domain, no matter how many time steps you allow Fluent to calculate.

[richard ben]

Hi, Pakk,

Thank you so much for your reply.

I think I increased the max number of steps to 1x10(9). I have a pipe with water running inside. And some of the particles just stopped in the middle of the pipe where the fluid velocity can't be zero. I'm trying to attach a pic but haven't figured out how to do that.

BTW do you know how to do this:

Please consider reducing rpvar dpm/parallel/loop-factor to reduce the number of incomplete tracks in parallel.
Current value is 10.

Someone said this: http://www.cfd-online.com/Forums/flu...op-factor.html
I tried that way but still it didn't work.

Thanks,
Richard

[pakk]

You did not mention yet that you did it parallel.

Try it once in serial mode, and see if the problem is still there.

[richard ben]

I tried to run in serial but still got the same results. Any further suggestions?

Thanks