FVICs System

Description

The FVICs block within an input file is used to define the initial (starting) conditions for the finite volume variables within your simulation. Initial conditions may be applied to both the "unknowns" (nonlinear) or auxiliary variables. It computes the values of the variable at the cell centroids.

FVICs Block

The preferred syntax is to create a top-level "FVICs" block with subblocks defining the initial conditions for one or more variables.

[FVICs<<<{"href": "index.html"}>>>]
  [u_ic]
    type = FVFunctionIC<<<{"description": "An initial condition that uses a normal function of x, y, z to produce values (and optionally gradients) for a field variable.", "href": "../../source/fvics/FVFunctionIC.html"}>>>
    variable<<<{"description": "The variable this initial condition is supposed to provide values for."}>>> = 'u'
    function<<<{"description": "The initial condition function."}>>> = parsed_function
  []
[]
(moose/test/tests/fvics/function_ic/parsed_function.i)

FVICs from an Exodus File

MOOSE contains a shortcut syntax for reading solutions from an Exodus file for the initial condition from right within the Variables. The name of the variable and the time step from which to read the solution must be supplied.

[Variables<<<{"href": "../Variables/index.html"}>>>]
  [u]
    type = MooseVariableFVReal<<<{"description": "Base class for Moose variables. This should never be the terminal object type", "href": "../../source/variables/MooseVariableFV.html"}>>>
    initial_from_file_var<<<{"description": "Gives the name of a variable for which to read an initial condition from a mesh file"}>>> = u
  []
[]
(moose/test/tests/fvics/file_ic/file_restart.i)

Sanity checks on FVICs

  • Multiple FV initial conditions may not be applied to the same variable on the same block

  • Global initial conditions will conflict with subdomain or boundary restricted ICs on the same variable

Available Objects

  • Moose App
  • FVConstantICSets a constant field value.
  • FVFunctionICAn initial condition that uses a normal function of x, y, z to produce values (and optionally gradients) for a field variable.

Available Actions