Learning Forum

[Anadi_Mondal]

Hello,

I am getting the following warning message while running a transient simulation with DPM and EWF " Warning: 0.1053% of the total discrete phase mass was not tracked for the expected residence time: 6.05e-16 s less on a mass-weighted average (which is 0.0000% of the total of their total age or 0.0000% of the time step".How do I get rid of this warning?

Here the DPM setting is also attached. Please have a look.

Thank you,

Anadi

 

[Rob]

Turning on High-res tracking is recommended, it's default in the later releases. Chances are you're either seeing particles stuck somewhere, check the time step, convergence and read the TUI to see if there are aborted or incomplete trajectories. 

[Anadi_Mondal]

Hello Rob,

I start the same simulation on two versions- ANSYS 2019 and ANSYS 2021R2. For the case of 2019, it shows the warning 'certain percentage of total discrete phase mass was not tracked ' at the first time step when I stop the simulation and start again. Later, it didn't show any warning.

But for the case of 2021R1 , I got the warning at every time step although I selected high-resolution tracking. I checked with the different time steps but got the same warning. I didn't get any aborted and incomplete particles in the console window.

In this transient simulation, the  residual of the continuity equation varies between 10^-1 and 10^-5.

Why warning frequency is different in different versions? and what is your recommendation now to solve the error?

Anadi

[Rob]

It's a warning, so it's more a case of working out where the particles are going - if the flow isn't well converged it could just be some trajectories are stuck in recirculation zones.