glens_law_mod

Provides a concrete implementation for the abstract_viscosity type using Glen's flow law.

Uses

Help
Graph Key

Nodes of different colours represent the following:

Solid arrows point from a submodule to the (sub)module which it is descended from. Dashed arrows point from a module or program unit to modules which it uses.

Interfaces

public interface glens_law_viscosity

private pure function constructor(b_val, index) result(this)

Author: Christopher MacMackin
Date: April 2017

Instantiates an instance of a viscosity object implementing Glen's flow law.

Arguments

Type	Intent	Optional	Attributes		Name
real(kind=r8),	intent(in)			::	b_val	The coefficient, $B$ , in Glen's flow law.
real(kind=r8),	intent(in)			::	index	The index, $n$ , in the exponent of Glen's flow law.

Return Value type(glens_law_viscosity)

The viscosity object being created.

Derived Types

type, public, extends(abstract_viscosity) :: glens_law_viscosity

An implementation of Glen's flow law to describe glacier viscosity. It takes the form $\eta = \frac{1}{2}BD^{1/n-1},$ where $D = \sqrt{D_{ij}D_{ij}/2$ is the second invarient of the strain rate $D_{ij} = \frac{1}{2}\left(\frac{\partial u_i}{\partial x_j} + \frac{\partial u_j}{\partial x_i} \right).$ Here, $B$ is treated as a constant, although it may be parameterised as a function of temperature.

Components

Type	Visibility	Attributes		Name		Initial
real(kind=r8),	private		::	b_val	=	1.0_r8
real(kind=r8),	private		::	index	=	3._r8

Constructor

private pure function constructor(b_val, index)	Instantiates an instance of a viscosity object implementing Glen's flow law.

Type-Bound Procedures

procedure, public :: ice_viscosity => glens_ice_viscosity	Returns the viscosity for the ice.

Functions

private pure function constructor(b_val, index) result(this)

Author: Christopher MacMackin
Date: April 2017

Instantiates an instance of a viscosity object implementing Glen's flow law.

Arguments

Type	Intent	Optional	Attributes		Name
real(kind=r8),	intent(in)			::	b_val	The coefficient, $B$ , in Glen's flow law.
real(kind=r8),	intent(in)			::	index	The index, $n$ , in the exponent of Glen's flow law.

Return Value type(glens_law_viscosity)

The viscosity object being created.

private function glens_ice_viscosity(this, velocity, temperature, time) result(viscosity)

Author: Christopher MacMackin
Date: April 2017

Calculates the viscosity of ice using Glen's flow law. See the documentation of the glens_law_viscosity object for a description of this parameterisation.

Arguments

Type	Intent	Optional		Name
class(glens_law_viscosity),	intent(in)		::	this
class(vector_field),	intent(in)		::	velocity	The velocity field of the ice for which the velocity is being calculated
real(kind=r8),	intent(in)		::	temperature	The temperature of the ice for which viscosity is being calculated.
real(kind=r8),	intent(in),	optional	::	time	The time at which the viscosity is being calculated. If not present then assumed to be same as previous value passed.

Return Value class(scalar_field), pointer

The value of the viscosity

glens_law_mod Module

Contents

Interfaces

Derived Types

Functions

Uses

Contents

Interfaces

Derived Types

Functions

Interfaces

public interface glens_law_viscosity

private pure function constructor(b_val, index) result(this)

Arguments

Return Value type(glens_law_viscosity)

Derived Types

type, public, extends(abstract_viscosity) :: glens_law_viscosity

Components

Constructor

Type-Bound Procedures

Functions

private pure function constructor(b_val, index) result(this)

Arguments

Return Value type(glens_law_viscosity)

private function glens_ice_viscosity(this, velocity, temperature, time) result(viscosity)

Arguments

Return Value class(scalar_field), pointer