Thermal Exponent#

Thermal Exponent = CONSTANT <float> [T]

Description / Usage#

This card is used to specify a thermal exponential factor for CARREAU_WLF, BINGHAM, THERMAL, EPOXY, FILLED_EPOXY, POWERLAW_SUSPENSION and CARREAU_SUSPENSION viscosity models, as selected in the Liquid Constitutive Equation card. The value represented by the thermal exponent varies between these liquid constitutive models; the appropriate values for each model is indicated below.

Definitions of the input parameters are as follows:

CONSTANT

Name of the model for the thermal exponent.

  • <float> - the value of the thermal exponent for the viscosity model specified in the Liquid Constitutive Equation card.

  • for the BINGHAM, THERMAL, EPOXY, or FILLED_EPOXY model,

    • <float> - the Eμ/R parameter. This has the dimensions of temperature in whatever units are consistent with the problem and describes the thinning of viscosity with temperature.

  • for the CARREAU_WLF model model,

    • <float> - the c1 constant of the equation for the temperature-dependent shift factor.

  • for the POWERLAW_SUSPENSION or CARREAU_SUSPENSION model,

    • <float> - the exponent for the Krieger viscosity model, m.

LEVEL_SET

Name of the model for level-set dependent thermal exponent factor. Allows for this exponent level to be a function of the level-set field. Specifically used for changing the thermal exponent from one constant value on the negative side of the interface to another constant value on the positive side. The model requires three floats:

  • <float1> - the value of thermal exponent in the negative regions of the level set function.

  • <float2> - the value of thermal exponent in the positive regioons of the level-set function.

  • <float3> Length scale over which the transition occurs. If this parameter is set to zero, it will default to one-half the Level-Set Length Scale value specified.

Examples#

The following is a sample card that sets the thermal exponent to 0.5.

Thermal Exponent = CONSTANT 0.5

Technical Discussion#

See Description/Usage for Liquid Constitutive Equation card.