Basal friction relation which satisfies Tb = min(|Tb'|, a*p) u/|u|. More...

#include <BasalFrictionRelation.H>

Inheritance diagram for PressureLimitedBasalFrictionRelation:

Collaboration diagram for PressureLimitedBasalFrictionRelation:

Public Types
enum	Model { Tsai, Leguy, MAX_MODEL }

Public Member Functions
virtual void	computeDissipation (FArrayBox &a_dissipation, const FArrayBox &a_basalVel, const FArrayBox &a_C, const Real &a_scale, const LevelSigmaCS &a_coords, const DataIterator &a_dit, int a_level, const Box &a_box) const

void	updateThermodynamics (Vector< LevelData< FArrayBox > * > *a_tillWaterDepth)

virtual void	computeAlpha (FArrayBox &a_alpha, const FArrayBox &a_basalVel, const FArrayBox &a_C, const Real &a_scale, const LevelSigmaCS &a_coords, const DataIterator &a_dit, int a_level, const Box &a_box) const
	Computes cell-centered effective basal friction coeffcient $\alpha$ such that $\tau_b = \alpha (u_b, C) u_b$ . More...

	PressureLimitedBasalFrictionRelation (Real a_a, Real a_p, Real a_maxTillWaterDepth, Real a_tillPressureFactor, Model a_model, BasalFrictionRelation *a_bfr)

virtual BasalFrictionRelation *	getNewBasalFrictionRelation () const
	creates a new copy of subclass objects. More...

virtual Real	power () const

Public Member Functions inherited from BasalFrictionRelation
virtual	~BasalFrictionRelation ()

Additional Inherited Members
Static Public Member Functions inherited from BasalFrictionRelation
static BasalFrictionRelation *	parse (const char *a_prefix, int a_recursion)
	Run-time configuration of BasalFrictionRelation objects. More...

Detailed Description

Basal friction relation which satisfies Tb = min(|Tb'|, a*p) u/|u|.

Tb' is any BasalFrictionRelation a is a constant (for now) coefficient, N is the local (hydrostatic) pressure For a ~ 1, Tb = Tb' is applied most places, with the Coulomb law Tb = a*p*u/|u| imposed at flotation

Three laws are supported, one due to Tsai 2015

$\tau_b = \min(|\tau _b^{\prime}|, \alpha N^p) u/|u|$

the second due to Schoof 2005, Gagliardini 2007, and Leguy 2014, which is smoother but otherwise similar. We use the form from Leguy 2014

$\tau _b = \tau _b^{\prime} ( N^p / (\alpha |u| + N^p ) )^{1/p}$

Run-time configuation is carried out in BasalFrictionRelation::parse. If the string A.B.basalFrictionRelation = pressureLimitedLaw is found, the expected form is

BasalFrictionPressureLimitedLaw.coefficient = <float, optional, defualt 1.0> ( $\alpha$ )
BasalFrictionPressureLimitedLaw.power = <float, optional, defualt 1.0> ( )
BasalFrictionPressureLimitedLaw.model = Tsai|Leguy (optional , default Tsai)
BasalFrictionPressureLimitedLaw.basalFrictionRelation = <valid BasalFrictionRelation>

Member Enumeration Documentation

◆ Model

enum PressureLimitedBasalFrictionRelation::Model

Enumerator
Tsai
Leguy
MAX_MODEL

Constructor & Destructor Documentation

◆ PressureLimitedBasalFrictionRelation()

PressureLimitedBasalFrictionRelation::PressureLimitedBasalFrictionRelation	(	Real	a_a,
		Real	a_p,
		Real	a_maxTillWaterDepth,
		Real	a_tillPressureFactor,
		Model	a_model,
		BasalFrictionRelation *	a_bfr
	)

inline

Member Function Documentation

◆ computeAlpha()

void PressureLimitedBasalFrictionRelation::computeAlpha	(	FArrayBox &	a_alpha,
		const FArrayBox &	a_basalVel,
		const FArrayBox &	a_C,
		const Real &	a_scale,
		const LevelSigmaCS &	a_coords,
		const DataIterator &	a_dit,
		int	a_level,
		const Box &	a_box
	)		const

virtual

Computes cell-centered effective basal friction coeffcient $\alpha$ such that $\tau_b = \alpha (u_b, C) u_b$ .

Parameters

a_alpha	effective basal friction coefficient based on the local velocity field.
a_basalVel	Cell-centered basal velocity field.
a_C	Cell-centered coefficient field
a_coords	whole level geometry data
a_dit	index needed to retrieve data from a_coords
a_box	cell-centered box over which to do this computation

Implements BasalFrictionRelation.

References LevelSigmaCS::getH(), LevelSigmaCS::getThicknessOverFlotation(), LevelSigmaCS::gravity(), LevelSigmaCS::iceDensity(), and BasalFrictionRelation::power().

Referenced by computeDissipation().

◆ computeDissipation()

void PressureLimitedBasalFrictionRelation::computeDissipation	(	FArrayBox &	a_dissipation,
		const FArrayBox &	a_basalVel,
		const FArrayBox &	a_C,
		const Real &	a_scale,
		const LevelSigmaCS &	a_coords,
		const DataIterator &	a_dit,
		int	a_level,
		const Box &	a_box
	)		const