Category 11: Shear Rate Equation

The single boundary condition in this category is used to set a Dirichlet condition for the scalar shear rate equation. This differential equation is employed by the Phillips model for a suspension constitutive equation.

SH

BC = SH NS <bc_id> <float1> [float2]

Description / Usage

(DC/SHEAR_RATE)

This boundary condition is used to set a Dirichlet condition for the scalar shear rate unknown field.

Description of the input parameters is as follows:

SH	Name of the boundary condition (<bc_name>).
NS	Type of boundary condition (<bc_type>), where NS denotes node set in the EXODUS II database.
<bc_id>	The boundary flag identifier, an integer associated with <bc_type> that identifies the boundary location (node set in EXODUS II) in the problem domain.
<float1>	Value at which the scalar shear rate unknown will be fixed on node set <bc_id>.
[float2]	An optional parameter (that serves as a flag to the code for a Dirichlet boundary condition). If a value is present, and is not -1.0, the condition is applied as a residual equation. Otherwise, it is a “hard set” condition and is eliminated from the matrix. The residual method must be used when this Dirichlet boundary condition is used as a parameter in automatic continuation sequences.

Examples

An example of its used:

BC = SH NS 10 0.5

This boundary condition sets the scalar shear rate unknown to 0.5 on nodeset 10.

Technical Discussion

The scalar shear rate unknown field is otherwise known as the second invariant of the rate of deformation tensor.