MANGA Parameters - N-BodyShop/changa GitHub Wiki

Solver Properties

*bFastGas - Enables Prust & Chang (2019) multistepping (default=1). Recommended to most problems.

*bGasCooling - Must be set to 1 to enable cooling, e.g., EOS. Moving-mesh has not been tested for the case of default cooling.

*iRiemannSolver - different Riemann solvers: 0 - HLLC, 1 - HLL, 2 - Athena HLLC (HLLD in MHD mode), 3 Athena HLL (default = 0)

*dVoroKick - fraction of kick imparted to follow the fluid (default = 1.), 1 - Lagrangian mode, 0 static mesh

*dVoroMesh - fraction of kick to regularized cells (default = 1). Set to 0 for testing purposes or for strictly static cells, but otherwise it should always be set to 1.

*dHydroTheta - \theta for the slope limiter as defined in equation (20) of Chang, Quinn & Wadsley (2017). <0.5 means TVD (default = 0.5)

*dSmallRho - set the minimum rho allowed (default=1e-30)

*dSmallT - set the minimum temperature (default=0)

*bUseEntropy - use the entropy evolution for low speed (no shock) flows. It follows the logic of Springel (2010), but is rarely used.

*dMachThreshold - mach threshold below which we use the entropy equation. Again see Springel (2010). (default = 1.1)

*dEtaCourant - Courant conditions as specified from center of cell to effective radius; note that the Courant conditions is effectively half that of a regular grid code for regularized cells (default=0.8)

*dMsolUnit - units of mass in solar mass; for most moving-mesh runs, set it to cgs units, dMsolUnit = 5.028e-34

*dKpcUnit - units of length in kpc; for most moving-mesh runs, get it to cgs unit, dKpcUnit = 3.2408e-22

*bUseVanLeer - use Van Leer for the predictor step. See Chang, Davis & Jiang (2020). Setting it to 0 is only valid for pure hydrodynamics problems and is detailed in Chang, Quinn, & Wadsley (2017). (default = 1)

Gravity Properties

*bUseOldGravMethod - Use the "old" gravity method as defined by Springel (2010) section 5.2. This is actually the preferred method most of the time. (default = 0).

EOS parameters

*MesaDir - Root directory of MESA. Must be set equal to $MESA_DIR

Radiation solver properties

*bRadNoHydro - do not update hydro with results of radiation implicit source solve (see Chang, Davis, & Jiang 2020) (default = 0)

*bRadNoLorentz - do not perform Lorentz transformation to local fluid frame (again see Chang, Davis & Jiang 2020) (default = 0)

*dRedSpeedOfLight - reduced speed of light in cgs parameters (default=2.99792458e10; regular speed of light)

Opacity parameters

*OpacityName - name of opacity module; for now only "SimpleOpacity" is available

SimpleOpacity parameters

*dSimpleKappaPlanck - value of \kappa_{Planck} (default = 0)

*dSimpleKappaMean - value of \kappa_{mean} (default = 0)

*dSimpleKappaScatter - value of \kappa_{scatter} (default = 0)

Source Properties

*iUserGravType = 0

Problem Specific Parameters

Problem generator parameters

Diagnostic parameters

*iParticleTrack - particle id to track (default=-1)

*iAngleTrack- angle to track. Useful for radiation problems.