[FLASH-USERS] magnetic resistivity

[zdy0903]

Hi all！


When I want to set up a non-ideal plasma condition in magneticHD/NohCylindrical model, the units of magnetic resistivity troubles me. For example, if I want the resistivity of plasma equals to 1e-4 Ωm, (it should be 1e7 in CGS), the application abort cause the dt is not positive. Any settings of magnetic resistivity fail if we use CGS system. I can only achieve it when using the “none unit system”. The value is set to be 1e0 which correspond to a very small magnetic resistivity in theory. Do I made any mistakes in unit conversion in FLASH or we can only do simulations under very small magnetic resistivity condition?




Besides, an interesting thing attracts my attention. I find that we will get the same results when we delete the diffusive part (delete the “REQUIRES physics/Diffuse/DiffuseFluxBased” in config). And I haven’t found the Diffuse_magneticResistivity in DiffuseFluxBased file. (However there are Diffuse_therm and Diffuse_visc). Where do we calculate the magnetic diffusive part (the last term in MHD equations, user manual 14.3.1).




Zhang


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