If, when performing Steady DPM trajectory calculations in Fluent, the maximum number of steps are reached and a given particle still does not reach the outlet (or escape/trap boundary), that particle’s fate is reported as incomplete. To avoid a large number of incomplete particles, it is suggested to increase the value of “Max. Number of Steps” in the DPM panel. If increasing the number of maximum steps still results in a large number of incomplete particles, check if a larger re-circulation region is present in the solution. In such a case, it is probable that particles are kept churning in the re-circulation region and are not coming out of the domain, thus reported as incomplete. A large number of incomplete particles may also be caused by the non-converged flow field. In such a case, it might be useful to converge the flow without DPM, then inject the particles and iterate further. Most of the time, a large number of incomplete particles will affect the convergence and speed of the calculation. Therefore, a lower number of incomplete particles is desirable.