Algorithm Options

Conservative vs. Non-conservative

The following must be preceded by “ns.”

Description

Type

Default

do_mom_diff

If 0, solve velocity equation in convective form, else use conservation form

Int

0

do_cons_trac

If 0, solve for a passively advected tracer, else advect conservatively

Int

0

do_cons_trac2

If 0, solve for a passively advected 2nd tracer, else advect conservatively

Int

0

Note that Temperature is only non-conservative. For more details, see Fluid Equations.

Advection

IAMR has the option to use a Method of Lines (MOL) or Godunov scheme to compute the advective terms.

Description

Type

Default

ns.use_godunov

If true, use Godunov, else use MOL.

bool

true

For problems without embedded boundaries, there are additional options when using the Godunov method. The following must be preceded by “godunov.”

Description

Type

Default

use_ppm

Use the Piecewise Parabolic Method to construct edge states

bool

false

use_forces_in_trans

Use external forcing terms in constructing transverse derivatives

bool

false

Diffusion

The following must be preceded by “ns.”

Description

Type

Default

be_cn_theta

Diffusion solve fully implicit (1.0) or semi-implicit (<1 && >0.5)

Real

0.5

Note the default value of ns.be_cn_theta = 0.5 corresponds to the Crank-Nicolson method.