The Fluent Text User Interface (TUI) command for transient calculations was extended to allow this command to be added to a journal file /solve/dual-time-iterate 10 20 y 20 In the above command, Fluent will calculate 10 time steps with a maximum of 20 iterations each and then do 20 pollutant iterations. Alternatively, you can define it step by step: /solve> dual-time-iterate Number of physical time steps [3] 10 Number of iterations per time step [11] 20 Postprocess pollutant solution? [yes] yes Number of post-processing iterations per time step [20]