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?