I know solve_continuity.f and solve_energy_eq.f are used to solve continuity and energy equations. But I don’t know whether solve_scalar_eq.f is used to solve the momentum equation. If not, which file is used to solve the momentum equation?
The momentum equations are populated in several places throughout MFIX, but are ultimately solved in a linear equation solver routine. If you want to follow the logic structure, I would recommend looking at a file like source_u_g.f as a way forward. Here you can observe (in one direction) how source terms for the U_g momentum equation are collected and placed into matrix structure. Once you understand that, begin exploring how other sources are managed (like drag). Finally, look into the linear equation solver routines. Begin that journey in the file solve_lin_eq.f which shows the casing stuctures so you can follow the correct file path.
Thanks! I’ll read the files later.