Learning Forum

[zoelle.wong]

Dear FLUENT support team,

I need to include a temperature dependent Lorentz-Force terms into my momentum equations and a customized electrical conductivity UDF  under "materials". This magnetic force is not an external magnetic field, but rather a field induced through a current travelling between an electrode and anode.

I was curious if it is possible to integrate this source term into the FLUENT MHD module. I also don't see an option to alter the electrical conductivity under "materials" unless the MHD module is enabled. 

Currently, it seems that the .c files for modifying source terms in the FLUENT MHD module are inaccessible to users. If this is the case, does FLUENT have some starter marcros on how to integrate a customized electrical conductivity? I currently have a UDF for a time invariant source term, viscosity, thermal conductivity and constant specific heat. 

Thank you so much for your time

[Rob]

Electrical conductivity material property isn't available without a model for something that needs it, so that makes sense. Re the other sources etc, check the documentation and tutorials. Can you set any cell zone sources once the MHD module is active?  Depending on what you're doing you may want to write the models yourself, and/or explore what Fluent & Maxwell combined can do for you. 

[zoelle.wong]

I see. I can append source terms into the model with MHD module turned on, but I'm not sure how to couple the source terms to the built-in MHD modules. 

You mentioned coupling Fluent and Maxwell, what are best practices that you recommend to reduce computational runtime? For instane, for every 1 Fluent simulation is it faster to simulate Maxwell for 5 iterations? I understand this tends to be application based, but am curious about your input regarding mesh refinement and temporal resolution. 

[Rob]

Application based - it really comes down to how much the change in one solver alters the result in the other. There are some coupling tutorials in the Help system, from Fluent's Help navigate up the system and look for System Coupling.