Reply To: Orszag Tang in ANSYS Fluent

[zoelle.wong]

For recording purposes and future users, I figured out the diverging turbulent viscosity ratio was due to erroneous fluid transport properties. 

After enabling the MHD Module in ANSYS, one will need to account for the magnetic permeability and electrical conductivity in the fluid properties under "create/edit materials". For the Orszag-Tang case, these values along with viscosity need to be set to 1. Density, Ratio of Specific Heats (cp/cv) and Pressure need to be set judiciously such that the fluid's speed of sound is equal to 1.0 through the relation: c^2 = gamma*P/rho = 1 where c is the speed of sound, gamma the ratio of specific heats, P the pressure, and rho the density. More information can be found here for boundary and initial conditions.

 

 

For the case of 1 set of periodic boundary conditions, the velocity gradient field looked like the following during initialization (when using patch utility). However, these results are still under development - note that the current results are no longer diverging.