Initialize#

Initialize = {char_string} <integer> <float> [varies]

Description / Usage#

This optional card provides a mechanism to set one of the field variables to a constant value within the current material block. Definitions of the input parameters are as follows:

<char_string>

Permissible values for this input string are any variable names identified in source file rf_fem_const.h beginning at the section labeled Variable Names of unknowns, though they should be active in this material block. Examples include, but are not limited to, the following:

VELOCITY1, VELOCITY2, VELOCITY3 (V123),MESH_DISPLACEMENT (MD123), SOLID_DISPLACEMENT (SD123), MASS_FRACTION, TEMPERATURE, PRESSURE,VOLTAGE, FILL, LS, POLYMER_STRESS (6 components, 8 modes), VELOCITY_GRADIENT (9 components), SHEAR_RATE, VOLF_PHASE (6 phases), POR_LIQ_PRES, POR_GAS_PRES, POR_POROSITY, POR_SATURATION, POR_LAST, LAGR_MULT (LM123), SURF_CHARGE, EXT_VELOCITY, EFIELD(123), SHELL (4 variables), SPECIES (7 variables).

Note: for a comprehensive list of initializable variables, consult Volume 1 “Initialize” card.

Species number to be initialized if the value of {char_string} is one of the SPECIES variables (see Technical Discussion); otherwise, set <integer> to zero.

<float>

Value to which the variable should be initialized.

Multiple applications of this card are valid; Goma automatically counts the number of Initialize cards.

Examples#

Following is a sample card:

INITIALIZE = POLYMER_STRESS11 0 1.25E4

Technical Discussion#

This card provides the means to set initial values for any of the field variables in the element block for a particular material. Since the setting of variables initialized on this card takes place after reading the initial guess (see function init_vec in file rf_util.c), it can be used to override the value in the initial guess file.

In order to set a field to a specific value over the entire problem domain, a similar Initialize capability is provided as a global variable in the General Specifications section of the Goma input file. Please check in the Problem Description section of this manual.

Note, the SPECIES_UNK variables are NOT used to initialize any of the species variables. Rather, the special definition called MASS_FRACTION is the variables used in Goma input or mat files for this input record. Multiple species are initialized by combining MASS_FRACTION with the second parameter (<integer>) on this card. These cards are particularly handy for mass transfer problems, where the initial conditions need to specify different concentrations of the same species in different materials.

Note: for a comprehensive list of initializable variables, consult Volume 1 “Initialize” card.