Study and Study Step Types

The main study step types — most of them available as a study in the window — are listed in Table 20-2. Some studies require add-on modules, and these are listed in Table 20-3 (in that list, the submenu under in the branches appears in parentheses for the study types that are available as individual study steps).

Also see Study Extension Steps and Advanced Study Extension Steps for additional information about some study steps that do not generate equations and which can only be used in combination with other study steps. In Table 20-2, these are listed as supplemental studies and study steps.

Icon	Study or Study Step	Brief Description
	Empty Study	An Empty Study creates a Study node with no study steps.
	General Studies	Studies that are generally available, such as Stationary and Time Dependent.
	Preset Studies/Preset Studies for Selected Physics Interfaces	If you have added a single-physics interface, you find suggested studies under this node. If you have added multiple physics interfaces, you find studies applicable to all physics interfaces that you have added.
	More Studies	This branch contains study types for which the selected physics interfaces are not automatically adapted. Instead, these physics interfaces have to be adapted manually using the Model Builder.
	Preset Studies for Some Physics Interfaces	Under this node, studies applicable to all physics interfaces that you have chosen to solve for appear.
	Preset Studies for Selected Multiphysics	Under this node, studies applicable to the multiphysics couplings that you have chosen to solve for appear.
	Suggested by Some Physics Interfaces	Under this node (under Preset Studies for Selected Physics Interfaces), study types common to more than one physics interface appear if you have added more than two physics interfaces.
	Name of physics interface	Under a node with the name of a physics interface under Preset Studies for Selected Physics Interfaces, study types specific to that physics interface appears.
Stationary Studies and Study Steps
	Stationary	For a stationary or steady-state situation where you can use a stationary solver. This study type is also used for optimization problems that are constrained with a stationary PDE. Adds a Stationary study step. You can also choose to create a parametric continuation solver.
Time-Dependent Studies and Study Steps
	Time Dependent	For a time-dependent or transient simulation using a Time-Dependent Solver for computing the solution over time. This study type is also used for optimization problems that are constrained with a time-dependent PDE. Adds a Time Dependent study step.
	Time Discrete	Only available as a Time Dependent study step. Use it to perform time-dependent analysis using the projection method.
	Frequency to Time FFT	This study step performs an FFT (or nonuniform Fourier transform) from the frequency domain (the input) to the time domain for a time-dependent study.
Eigenfrequency Studies and Study Steps
	Eigenfrequency	This study is similar to an Eigenvalue study but computes the eigenfrequencies instead of the eigenvalues. Adds an Eigenfrequency study step.
	Eigenvalue	This study uses a formulation to compute eigenvalues and eigenmodes using an eigenvalue solver. Adds an Eigenvalue study step.
Frequency Domain Studies and Study Steps
	Frequency Domain	For a study in the frequency domain such as wave equations or frequency response analysis. Adds a Frequency Domain study step.
	Frequency Domain Perturbation	Use this study step for studies of small oscillations about a bias solution. This study step follows a study step that computes the stationary (or bias) solution and computes a perturbed solution of the linearized problem around the linearization point (or bias point) computed in the first step.
	Time to Frequency FFT	This study step performs an FFT from the time domain (the input) to the frequency domain (output) for a frequency-domain study.
Study Extensions Steps
	Batch	Use this step to start a COMSOL Multiphysics batch process that solves the current study on your computer.
	Batch Sweep	Use this step to find the solution to a sequence of stationary or time-dependent simulations that arise when you vary some parameters of interest.
	Cluster Computing	Use this step when you want to submit COMSOL Multiphysics batch jobs to a job scheduler that in turn runs the batch job on a second computer or cluster.
	Cluster Sweep	Use this step to find the solution to a sequence of stationary or time-dependent simulations that arise when you vary some parameters of interest.
	Combine Solutions	Use this step to combine two solutions; for example, two time-dependent simulations over two different time spans that you want to postprocess as a single time-dependent solution.
	Function Sweep	This is a special case of Parametric Sweep study step, where the solver sweeps over functions defined under a Switch node defined under Global Definitions>Functions.
	Material Sweep	This is a special case of Parametric Sweep, where the solver sweeps over materials defined under a Switch node defined under Materials.
	Model Reduction	Use this step to create a reduced-order model from a time-dependent or frequency-domain simulation.
	Multigrid Level	This can be added as a subnode to other study step nodes to describe a geometric multigrid level used by the study.
	Parametric Sweep	Use this step to find the solution to a sequence of stationary or time-dependent problems that arise when you vary some parameters of interest. Add to a study to perform a parametric variation on other studies.
	Sensitivity	Use this step to add a sensitivity analysis to the study. Using a Sensitivity study node you can add sensitivity functions at the study level and use model parameters as global control variables.
	Study Reference	Use this step to refer to another study in the model.