I have studied “Pulsating 2D fluidized bed” (3.11. Advanced Tutorials — MFiX 21.3 documentation) in MFIX tutorial. In this tutorial, some files are provided to generate pulsating inflow boundary condition. I know the data_kf_0001.txt file need to be written by ourself. But there are some other .f files in this case. My questions are:
(1) How do I know what files (for example, data_kf_0001.txt, usr_mod.f, usr0.f, usr1.f, usr_init_namelist.f and usrnlst.inc in “Pulsating 2D fluidized bed” case) are needed if I want to embed UDFs to realize one function?
(2) Where can I find those essential files, for example usr_mod.f, usr0.f, usr1.f, usr_init_namelist.f and usrnlst.inc in “Pulsating 2D fluidized bed” case.