#EBAMRCNS
This is a code that solves the compressible Navier Stokes equations in the context of complex geometry. The boundary conditions and initial conditions live in the IBC classes. This is all written in the Chombo infrastructure from LBNL. See the Chombo web page: for Chombo documentation.
mpirun -np NPROC navier2d...ex blah.inputs
where NPROC is the number of processors
blah.inputs is the input file name
###Shocktube initial/boundary condition
The initial conditions here are zero velocity and a sharp high/low pressure/density interface. The boundary conditions in this particular example are no flow/no slip velocity/insulated and the intitial condition is jump in state (think of it as a shock tube with complex geometries). There are other implemented in the src directory.
###input params you should be ok with changing:
- restart file --- starting from checkpoint thing
- logflag --- whether to take logs of pressure and density for output
- cfl --- cfl number (needs to be less than 1, preferably 0.1-0.5
- max_step --- maximum number of time steps
- tag_buffer_size --- number of cells added around each tagged cell (should be at least 1)
- regrid_interval --- how often to regrid
- gamma --- ratio of specfic heats
- domain_length --- length of the domain (only the x value used, I think)
- max_level --- highest amr level number
- n_cell --- number of cells on level 0
- ref_ratio --- refinement ratios
- max_grid_size --- maximum size of any box in domain
- checkpoint_interval --- how often to checkpoint
- plot_interval --- how often to write plot files
- which_geom --- which geometric configurtion you are using (1 ramp, 2 slab, 4 cylinder, 5 sphere... see GodunovGeom.cpp for more)
- ramp_normal --- normal vector of the ramp (for which_geom == 1)
- ramp_alpha --- y intercept of the ramp
- do_diffusion --- whether to turn on or off diffusion terms ( false == inviscid Euler)
- mu_viscosity --- viscosity
- lambda_viscosity --- set this = -2/3 mu_viscosity
- explosion_p0 --- low pressure
- explosion_r0 --- low density
- explosion_p1 --- high pressure
- explosion_r1 --- high density
- explosion_size --- where the interface lies
=-=-=-=-=-=-=-=- ###inflow/outflow initial/boundary condition =-=-=-=-=-=-=-=- This is an inflow/outflow problem. For this one you specify a preshock state and the mach number for your calculation as well as where the shock starrts
##input params you should be ok with changing:
- restart file --- starting from checkpoint thing
- logflag --- whether to take logs of pressure and density for output
- cfl --- cfl number (needs to be less than 1, preferably 0.1-0.5
- max_step --- maximum number of time steps
- tag_buffer_size --- number of cells added around each tagged cell (should be at least 1)
- regrid_interval --- how often to regrid
- gamma --- ratio of specfic heats
- domain_length --- length of the domain (only the x value used, I think)
- max_level --- highest amr level number
- n_cell --- number of cells on level 0
- ref_ratio --- refinement ratios
- max_grid_size --- maximum size of any box in domain
- checkpoint_interval --- how often to checkpoint
- plot_interval --- how often to write plot files
- which_geom --- which geometric configurtion you are using (1 ramp, 2 slab, 4 cylinder, 5 sphere... see GodunovGeom.cpp for more)
- ramp_normal --- normal vector of the ramp (for which_geom == 1)
- ramp_alpha --- y intercept of the ramp
- do_diffusion --- whether to turn on or off diffusion terms ( false == inviscid Euler)
- mu_viscosity --- viscosity
- lambda_viscosity --- set this = -2/3 mu_viscosity
- preshockdense --- pre shock density
- preshockpress --- pre shock pressure
- shock_mach --- mach number of the shcok
- shock_center --- where in the domain the shock lives
##See src/GodunovGeom.cpp for the available geometries.
##The interface is hard to use but the results are cool.
##Here is the paper that describes the algorithm: @ARTICLE{compress_ns, author ={Daniel T. Graves and Phillip Colella and David Modiano and Jeffrey Johnson and Bjorn Sjogreen and Xinfeng Gao}, title = {A Cartesian Grid Embedded Boundary Method for the Compressible {N}avier {S}tokes Equations}, journal = {Communications in Applied Mathematics and Compuational Science}, year = 2013, volume = 8, number = 1, pages = "99-122" }