Transport evaluators#

Only dispersivity requires an evaluator unique to transport.

Mechanical Dispersion Model Evaluator#

src/pks/transport/EvaluatorMDM.hh

Evaluates a dispersion tensor.

The dispersion tensor may be parameterized by a variety of different models, and is specified by region to allow different models across, e.g. stream vs sheet flow, or fracture vs matrix.

Note that this computes the dispersion coefficient tensor, units [m^2 s^-1].

It does NOT include the water content term which multiplies this tensor to become the diffusion tensor. This is different from Amanzi, which uses the MDM class to include the water content term.

“evaluator type” = “dispersion tensor”

Isotropic Dispersion#

src/pks/transport/MDM_Isotropic.hh

An isotropic mechanical dispersion model. Note this is rarely used for real problems, but is useful for testing. Note there is no velocity component to this model – it is equivalent to isotropic diffusion. Prefer to use Bear for a basic dispersion model.

“mechanical dispersion type” = “scalar”

OR

“mechanical dispersion type” = “isotropic”

mdm-scalar-spec

ONE OF:

  • “dispersivity [m]” [double]

OR

  • “dispersivity [m]” [function-spec]

OR

  • “dispersion coefficient [m^2 s^-1]” [double]

OR

  • “dispersion coefficient [m^2 s^-1]” [function-spec]

END

Bear’s Dispersion Model#

src/pks/transport/MDM_Bear.hh

An anisotropic mechanical dispersion model by Bear that splits longitudinal from transverse.

“mechanical dispersion type” = “Bear”

mdm-bear-spec

ONE OF

  • “alpha_l” [double] Longitudinal dispersivity.

OR

  • “longitudinal dispersivity [m]” [double]

END

ONE OF

  • “alpha_t” [double] Transverse dispersivity.

OR

  • “transverse dispersivity [m]” [double]

END

Burnett-Frind Dispersion Model#

src/pks/transport/MDM_BurnettFrind.hh

Anisotropic mechanical dispersion model by Burnett & Frind that splits the transverse component of dispersion between the horizontal and vertical.

“mechanical dispersion type” = “Burnett-Frind”

mdm-burnett-frind-spec

  • “alpha_l” [double] Longitudinal dispersivity/dispersion coefficient.

  • “alpha_tv” [double] Vertical transverse dispersivity/dispersion coefficient.

  • “alpha_th” [double] Horizontal transverse dispersivity/dispersion coefficient.

Lichtner-Kelkar-Robinson Dispersion Model#

src/pks/transport/MDM_LichtnerKelkarRobinson.hh

Anisotropic mechanical dispersion model by Lichtner, Kelkar, and Robinson, that splits vertical from horizontal and longitudinal from transverse.

“mechanical dispersion type” = “Lichtner-Kelkar-Robinson”

mdm-lichtner-kelkar-robinson-spec

  • “alpha_lv” [double] 0. Vertical longitudinal dispersivity/dispersion coefficient.

  • “alpha_lh” [double] 0. Horizontal longitudinal dispersivity/dispersion coefficient.

  • “alpha_tv” [double] 0. Vertical transverse dispersivity/dispersion coefficient.

  • “alpha_th” [double] 0. Horizontal transverse dispersivity/dispersion coefficient.