[FLASH-USERS] Error with StirTurb Run Trials

[seyit at mpe.mpg.de]

Dear Kezman,

This is an easy one. You shouldn't set gamma exactly equal to 1.0. Some
equations contain the factor (gamma-1). To achieve isothermality, just
make gamma close to one, like 1.001.

Best wishes,
Seyit


> Dear Flash-users,
>
> I have been running into a few errors while trying to run a basic StirTurb
> problem. What I essentially did was that, from the original StirTurb
> problem package, I only made a few noticeable changes to flash.par and
> added "REQUIRES physics/Hydro/HydroMain/unsplit/Hydro_Unsplit" to the
> Config file. Then I setup the problem using the command
>
> ./setup —auto -3d StirTurb -nxb=64 -nyb=64 -nzb=64 +ug
>
> and it successfully compiled.
>
> Running it however it proving to be a problem for me. When I set gamma to
> 1.4, I get a successful run but when I set it to 1.000 (Hoping to achieve
> isothermal conditions), I get an error that says:
>
> *DRIVER_ABORT: [hy_uhd_eigenParameters-A]: Zero or imaginary sound speed
> has obtained! Please try other (more diffusive) slope limiter, flux,
> order,
> cfl, etc.*
>
>
> Could you please help me decipher where I am going wrong?
>
> Thank in advance.
>
> Kezman
>
>
> *Provided below is the flash.par information I am using;*
>
> #       runtime parameters, nxb = nyb = nzb = 64
>
> 256^3 grid, gamma = 1.000
>
> xmax            = 1.
>
> xmin            = 0.
>
> ymax            = 1.
>
> ymin            = 0.
>
> zmax            = 1.
>
> zmin            = 0.
>
>
> basenm          = "driventurb_3d_"
>
> restart         = .false.
>
>
> # file numbers - if you restart you have to change the
> checkpointFileNumber
>
> checkpointFileNumber    = 0
>
> plotFileNumber          = 0
>
> particleFileNumber      = 0
>
>
> # set the time between dumps
>
> checkpointFileIntervalTime  = 0.01
>
> plotFileIntervalTime        = 0.
>
> particleFileIntervalTime    = 0.25
>
>
> # set the number of steps between dumps
>
> checkpointFileIntervalStep  = 0
>
> plotFileIntervalStep        = 0
>
> particleFileIntervalStep    = 0
>
>
> useParticles= .false.
>
> pt_numX = 5
>
> pt_numY = 5
>
> pt_numZ = 5
>
> pt_maxPerProc=1000
>
> plot_var_1  = "dens"
>
> plot_var_2  = "pres"
>
> plot_var_3  = "temp"
>
> plot_var_4  = "velx"
>
> plot_var_5  = "vely"
>
> plot_var_6  = "velz"
>
>
> plot_grid_var_1 = "mvrt"
>
>
> gamma           = 1.000
>
>
> cfl             = 0.8
>
> nend            = 10000
>
> tmax            = 0.05 # was originally 20.0
>
>
> xl_boundary_type      = "periodic"
>
> xr_boundary_type      = "periodic"
>
> yl_boundary_type      = "periodic"
>
> yr_boundary_type      = "periodic"
>
> zl_boundary_type      = "periodic"
>
> zr_boundary_type      = "periodic"
>
> st_stirmax           = 18.8478
>
> st_stirmin           =  6.2832
>
> st_energy            =  0.1
>
> st_decay             =  0.5
>
> st_freq              = 1
>
> eintSwitch          = 1.
>
>
> dtinit = 1.e-5
>
> dtmin = 1.e-12    # This parameter must be << minimum timestep
>
>                   #  in order to avoid numerical instability
>
>
> smallt = 1.e-15
>
> smalle = 1.e-10
>
>
> #   AMR refinement parameters
>
> #lrefine_max = 6
>
> #refine_var_1 = "dens"
>
>
> #These parameters below are only necessary for the Uniform Grid
>
>
> iProcs = 4      #num procs in i direction
>
> jProcs = 4      #num procs in j direction
>
> kProcs = 4
>
>
> # When using UG, iProcs, jProcs and kProcs must be specified.
>
> # These are the processors along each of the dimensions
>
>
> #FIXEDBLOCKSIZE mode ::
>
> # When using fixed blocksize, iGridSize etc are redundant in
>
> # runtime parameters. These quantities are calculated as
>
> # iGridSize = NXB*iprocs
>
> # jGridSize = NYB*jprocs
>
> # kGridSize = NZB*kprocs
>
>
> #NONFIXEDBLOCKSIZE mode ::
>
> # iGridSize etc must be specified. They constitute the global
>
> # number of grid points in the physical domain without taking
>
> # the guard cell into account. The local blocksize is calculated
>
> # as iGridSize/iprocs  etc.
>
>
> ## -------------------------------------------------------------##
>
> ##  SWITCHES SPECIFIC TO THE UNSPLIT HYDRO SOLVER               ##
>
> #       I. INTERPOLATION SCHEME:
>
> order           = 3      # Interpolation order (first/second/third/fifth
> order)
>
> slopeLimiter    = "vanLeer"   # Slope limiters (minmod, mc, vanLeer,
> hybrid, limited)
>
> LimitedSlopeBeta= 1.     # Slope parameter for the "limited" slope by Toro
>
> charLimiting    = .true. # Characteristic limiting vs. Primitive limiting
>
>
> use_avisc       = .false. # use artificial viscosity (originally for PPM)
>
> #cvisc          = 0.1     # coefficient for artificial viscosity
>
> use_flattening  = .false. # use flattening (dissipative) (originally for
> PPM)
>
> use_steepening  = .false. # use contact steepening (originally for PPM)
>
> use_upwindTVD   = .false. # use upwind biased TVD slope for PPM (need
> nguard=6)
>
> use_hybridOrder = .true.
>
>
> # Magnetic and Electric Fields:
>
> E_modificaton  = .true.
>
> energyFix      = .true.
>
> ForceHydroLimit = .false.
>
> prolMethod      = "injection_prol"
>
>
>
> #       II. RIEMANN SOLVERS:
>
> RiemannSolver   = "Hybrid"       # Roe, HLL, HLLC, LLF, Marquina
>
> entropy         = .true.     # Entropy fix for the Roe solver
>
> EOSforRiemann   = .true. # Call EOS in Riemann flux calculations
>
>
> #       III. STRONG SHOCK HANDELING SCHEME:
>
> shockDetect     = .true.     # Shock Detect for numerical stability
>
> ## -------------------------------------------------------------##
>
> ## ---------------------------------------------------------------##
>
> ##  SWITCHES SPECIFIC TO THE SUPER-TIME-STEPPING (STS) ALGORITHM  ##
>
> ##  NOTE: For details on using STS runtime parameters, please     ##
>
> ##        refer to user's guide (Driver chapter).                 ##
>
> useSTS                  = .false.
>
> nstepTotalSTS           = 5
>
> nuSTS                   = 0.2
>
> ## ---------------------------------------------------------------##
>