Segregated Step
The Segregated Step node () handles settings for one substep of a segregated iteration. This attribute uses a damped version of Newton’s method and can be used together with a Segregated attribute node.
For more background information about the method and termination settings, see The Segregated Solver and Damped Newton Methods.
General
Use the Variables list to specify variables to be solved for in this segregated step.
Select a Linear solver for the linear systems associated with the quantities specified by Variables. The available solvers are attribute nodes of the types Direct and Iterative.
Method and Termination
See the Fully Coupled Method and Termination section for all settings except for the following, which has a slightly different behavior as described:
For a Time-Dependent Solver, if Constant (Newton) is selected as the Nonlinear method, choose a Jacobian update: Minimal (the default), On every iteration, or Once per time step:
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On every iteration computes a new Jacobian for all iterations of Newton’s method.
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Minimal updates the Jacobian at least once and then only when the nonlinear solver fails during time stepping. It reuses the Jacobian for several nonlinear systems whenever deemed possible.
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Once per time step updates the Jacobian once per time step.
For a Stationary Solver or a parametric solver, if Constant (Newton) is selected as the Nonlinear method, choose a Jacobian update: Minimal (the default), On every iteration, or Once first iteration:
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On every iteration computes a new Jacobian for all iterations of Newton’s method.
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Minimal updates the Jacobian at least once and then only when the nonlinear solver fails during parameter stepping. It reuses the Jacobian for several nonlinear systems whenever deemed possible.
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On first iteration updates the Jacobian for the first subiteration for this segregated step.
The pseudo time stepping settings are not applicable for this node.