3. Implementation

The MHD model is implemented using the user-defined functions (UDF) as an ANSYS FLUENT add-on module, which is loaded into ANSYS FLUENT at run-time. The model is accessed through a number of UDF schemes. The magnetic induction equation given by Equations  2.2-8 or 2.2-10 and the electric potential equation given by Equation  2.3-4 are solved through user-defined scalar (UDS) transport equations. Other model-related variables such as the external magnetic field data, current density, Lorentz force and Joule heat are stored as user-defined memory (UDM) variables. The MHD model setup and parameters are input using the MHD Model graphical user interface (GUI) dialog box and a set of text user interface (TUI) commands described in Chapter  4. Detailed information can be found in the following sections: