GfsVariableTracer

From Gerris

A GfsVariableTracer is an advected scalar quantity which can also change in time due to user-defined source terms.

The syntax in parameter files is:

[ GfsVariable ] {
  cfl = 0.8
  gradient = gfs_center_van_leer_gradient
  scheme = godunov
}

where the parameter block is optional (the values shown here are the default values). The optional parameters are:

cfl

the maximum CFL number for advection of this tracer.

gradient

how to compute the tracer gradient in the Godunov advection scheme: either gfs_center_van_leer_gradient for a Van-Leer limited gradient estimation or gfs_center_gradient for a straight centered gradient estimation.

scheme

the advection scheme to use: either godunov for a Bell-Collela-Glaz second-order Godunov type scheme or none to switch advection off.

scheme = none can be used to define a variable which varies in time due only to user-defined source terms.

Examples

• B\'enard--von K\'arm\'an Vortex Street for flow around a cylinder at Re=160

  VariableTracer {} T

• Vortex street around a "heated" cylinder

  VariableTracer {} T

• Boussinesq flow generated by a heated cylinder

  VariableTracer T

• Convergence of the Godunov advection scheme

  VariableTracer {} T { gradient = gfs_center_gradient }

• Mass conservation

    VariableTracer T1

• Mass conservation with solid boundary

    VariableTracer T1