Solution Operation Nodes and Solvers

The first few sections provide some background information about the solvers and the algorithms used:

•	Selecting a Stationary, Time-Dependent, or Eigenvalue Solver

•	Remarks on Solver-Related Model Characteristics

•	Scaling of Variables and Equations

•	About the Stationary Solver

•	About the Parametric Solver

•	About the Time-Dependent Solver

•	About the Time Discrete Solver

•	The Eigenvalue Solver Algorithm

•	The Modal Solver Algorithm

•	The Time Explicit Solver Algorithms

About Solver Commands in the COMSOL Multiphysics Programming Reference Manual

The settings for the solver operation nodes listed in Table 19-5 are detailed. There is also a list of the References for the Solution Operation Nodes and Solvers.

Table 19-5: Solution Operation Nodes

Icon	Name	Description
	AWE Solver	Solve a parametric problem with asymptotic waveform evaluation.
	Dependent Variables	Handles the dependent variables solved for (initial values, scaling) and dependent variables not solved for (prescribed values).
	Eigenvalue Solver	Solve linear or linearized eigenvalue problems (also called eigenfrequency problems). Also see The Eigenvalue Solver Algorithm.
	FFT Solver	Use a forward FFT to transform a time-dependent solution to the frequency domain or an inverse NFT/FFT to transform a frequency-domain solution to the time domain.
	Modal Solver	To solve either parameter stepping (also called frequency response) or time stepping (also called transient response) problems using a reduced model. Also see The Modal Solver Algorithm.
	Optimization Solver	Solve PDE-constrained optimization problems. Requires the Optimization Module.
	Plug Flow Solver	Solve a plug flow reactor model (requires the Chemical Reaction Engineering Module).
	Stationary Solver	Solve linear and nonlinear stationary problems (also called static or steady-state problems). Also see About the Stationary Solver.
	Time-Dependent Solver	Solve time-dependent problems (also called dynamic or unsteady problems) using the BDF, generalized-α, or one of the available Runge-Kutta type of time-stepping methods. Also see About the Time-Dependent Solver.
	Time Discrete Solver	Solve time-dependent problems (dynamic or unsteady problems) that have already been discretized in time using, for example, the prev operator or the bdf operator.
	Time Explicit Solver	Solve time-dependent problems (also called dynamic or unsteady problems) using the family of Runge-Kutta explicit time-stepping schemes or the Adams-Bashforth 3 solver. Also see The Time Explicit Solver Algorithms.