OGS
[tag] compensate_non_equilibrium_initial_residuum

Enables computation of the non-equilibrium initial residuum \( r_{\rm neq} \) before the first time step. The forces are zero if the external forces are in equilibrium with the initial state/initial conditions. During the simulation the new residuum reads \( \tilde r = r - r_{\rm neq} \).

If this option tag is not given or set to false for all variables, the calculation and the use of the initial non equilibrium initial residuum is skipped. Otherwise, the calculation of the initial non equilibrium initial residuum is triggered, and the portions of the calculated initial residual vector, which are associated with the variables without this option enabled are set to zero.

With this equation variable option, one can flexibly set which portions of the equations can have initial non_equilibrium compensation. For example, in a numerical simulation of coupled THM processes in porous medium, if you want to avoid the initial stress influence the displacement result, you can simply set this option to true only for the variable of displacement in the variable configuration in the project file.

Additional info

From ProcessLib/ProcessVariable.cpp line 112

  • This is an optional parameter.
  • This parameter has a default value of false.
  • Data type: bool
  • Expanded tag path: process_variables.process_variable.compensate_non_equilibrium_initial_residuum
  • Go to source code: → ogs/ogs/master

Used in the following test data files