I use surface injection model in DPM for injecting evaporable liquid in air in unsteadystate. Untill when the liquid had not come into contact with air, the convergence for each time step (50 micro seconds) was quick (some ten to twenty iterations). Since when the liquid has started entering the high velocity air stream, as seen in the particle tracks, the energy residual has remained stagnated at 1.12e-6 (convergence criteria set is 1e-6) even after 500 iterations.

I will be grateful if somebody enlightens me on this.

Thanks, Prasad

Residuals are not the only convergence criterion we have and in more complex cases like yours it often happens that we don't reach the standard convergence limit. If your energy residual stagnates without large oscillations than you may assume convergence even though the value of the residual is somewhat elevated above the prescribed limit. Please see UG for an explanation, maybe you will then be able to identify the actual reason of this behaviour.

Good luck,

George