Problem definition¶

ndim (integer)

Number of dimensions in problem domain (1 or 2).

mx (integer)

Number of computational cells.

meqn (integer)

Number of equations in the system to be solved.

mwaves (integer)

Number of waves with non-zero speed in Riemann solution.

maux (integer)

Number of auxiliary variables.

mcapa (0 or 1)

• 0: No kappa array used.
• 1: Kappa array used.

xlower, xupper (real)

Endpoints of computational domain.

t0 (real)

Initial simulation time.

src_term (0 or 1)

mbc

Number of ghost cells.

mthbc_xlower, mthbc_xupper

Boundary condition to be used at left and right boundaries.

• 0: User-specified boundary condition (must modify :file:bcN.f to use this option).
• 1: Zero-order extrapolation (non-reflecting)
• 2: Periodic (must be specified at both boundaries).
• 3: Solid wall BC for systems where q(2) is the normal velocity.

Output Options¶

outstyle (1, 2, or 3)

• 1: Produce nout outputs at equally spaced intervals.
• 2: Produce output at a provided list of times (tout).
• 3: Produce output every iout timesteps with a total of ntot time steps.

verbosity (0 or 1)

• 0: Output a message to screen only when writing output files.
• 1: Output a message to screen at every time step.

Time stepping¶

dt_variable (0 or 1)

• 0: Use dt_initial for the size of all time steps.
• 1: Adjust the time step to achieve a desired CFL number.

dt_initial (real)

Step size for first time step.

dt_max

Maximum allowable time step size; usually set to 10^99.

cfl_desired

The time step will be adjusted at each step in order to achieve approximately this CFL at the next time step.

cfl_max

If this CFL number is exceeded in a step, the step will be rejected and retaken. This should be set somewhat larger than cfl_desired to avoid having many rejected steps.

max_steps

SharpClaw will abort if more than this number of steps is taken between outputs.

Numerical Scheme¶

time_integrator (1, 2, 3, 4)

• 1: 2-stage, 2nd-order SSP Runge-Kutta method
• 2: 4-stage, 2nd-order SSP Runge-Kutta method
• 3: 3-stage, 3rd-order SSP Runge-Kutta method
• 4: 10-stage, 4th-order SSP Runge-Kutta method

lim_type (0, 1, 2)

The type of limiter to use:

• 0: No limiting (piecewise-polynomial interpolation)
• 1: TVD reconstruction
• 2: WENO reconstruction

mthlim (integer)

The meaning of mhtlim depends on the value of lim_type:

• lim_type =0:

  • mthlim =3: Third-order polynomial reconstruction
  • mthlim =7: Seventh-order polynomial reconstruction

• lim_type =1:

  • The value of mthlim selects a TVD limiter exactly as in Clawpack

• lim_type =2:

  • The value of mthlim does not matter; 5th-order WENO reconstruction is used