Reply To: Orszag Tang in ANSYS Fluent

[zoelle.wong]

Couple of follow up questions:

Per my previous post I changed the initial and boundary conditions to be the following:

I inputted the velocity profile via patching during initialization and cross compared the initialized flow field when using a INIT_DEFINE() UDF. When comparing the initialized velocity contour plots, they looked the same. I ran this as a transient simulation for roughly 50 timesteps, with each timestep being 1e-3 without a magnetic field, and the results looked ok. 

However, when turning the MHD module on, initializing the MHD solver, and patching the expression for the magnetic field, the turbulent viscosity ratio is limted to 1e5. The contour plot for turbulent viscosity ratio is shown below. The mesh is a structured and isotropic. If FLUENT is limiting the turbulent viscosity, does this imply the mesh needs a higher refinement? Or is there something in the MHD module that was not turned on? Finally, is there a UDF macro one can use for initailizing a Force (e.g electric and magnetic) besides using the patching option for Bx, By etc? 

 

Thank you so much for your time!