Polymer Time Constant

Polymer Time Constant = {model_name} <float> [t]

Description / Usage

This card is used to specify the polymer time constant associated with the Polymer Constitutive Equation card. It is a required card for the OLDROYDB, GIESEKUS and PTT options. Definitions of the input parameters are as follows:

Definitions of the input parameters are as follows:

{model_name}	Permissible names for the viscosity model are CONSTANT, POWER_LAW and CARREAU.
CONSTANT	a simple constant viscosity, Newtonian fluid.
POWER_LAW	a power-law model
CARREAU	a Carreau strain-rate thinning or thickening relation

Input parameters are not identified for the latter two models as they have not worked since the multimode port. They could be made to work again if the proper tweaking is done to the input parser, but are not currently functional.

If the polymer time constant varies with properties, it must do so in the same way as the polymer viscosity; thus, the model on this card must be the same as the model selected on the Polymer Viscosity card.

All three models are described in detail in Bird, et. al. (1987).

Examples

The following is a sample card that sets the polymer time constant to 1.0:

Polymer Time Constant = CONSTANT 1.0

Technical Discussion

No Discussion.

References

Bird, R. B., Armstrong, R. C., and Hassager, O. 1987. Dynamics of Polymeric Liquids, 2nd ed., Wiley, New York, Vol. 1.