Simcenter Nastran Link Reference

In Simcenter STAR-CCM+, you specify the settings for co-simulation in a co-simulation link under the External Links node.

A co-simulation link node, External Links > [Link 1], appears automatically in the simulation tree when you create an external physics continuum. This node represents a connection to an external application and allows you to specify the settings for co-simulation.

[Link 1] Properties

Link Type: Describes the type of connection. Read-only.
Link Priority: Specifies the order in which the links are executed.

Link Models

In a Simcenter STAR-CCM+ simulation, you access the co-simulation framework by activating co-simulation models in the physics continua. These models determine the physics of the coupling, including the fields that can be exchanged with the partner simulation.

Link models configure the connection to a partner application or file. The link icon changes based on the application, or file, that Simcenter STAR-CCM+ connects to through the link. The link model must be appropriate for the co-simulation or file export model selected in the physics continuum.

For Simcenter Nastran co-simulation, the following models are available:

Co-Simulation API: This model is always required. It enables communication between Simcenter Nastran and Simcenter STAR-CCM+ through the Simcenter STAR-CCM+ Co-Simulation API. For more information on the API, see Co-Simulation API.
Simcenter Nastran Launcher: This model is optional. It allows Simcenter STAR-CCM+ to launch Simcenter Nastran automatically when you run the co-simulation.

[Link 1] Conditions and Values

You specify the general settings of the co-simulation under the [Link 1] > Conditions and [Link 1] > Values nodes.

Simcenter Nastran Version

Specifies the version of Simcenter Nastran that you are running. The available options include the recommended versions (see the External Package Support section of the Simcenter STAR-CCM+ Release Notes), as well as a Custom version. The Custom version allows you to specify a version other than the recommended. In general, you are advised to use one of the recommended versions, as compatibility for other versions is not guaranteed. When using the Custom version, set the version using the Values > Custom Code Version node.

Launch Partner Option

Determines the method for launching Simcenter Nastran:

Method	Corresponding Value Nodes
Do Not Launch Requires you to launch Simcenter Nastran separately, for example from a terminal or a command prompt. For information on the launch command, see Simcenter Nastran Launch Command Reference.	None
Launch Application Simcenter STAR-CCM+ automatically launches the Simcenter Nastran simulation when you run the co-simulation. With this option, you provide the locations of the Simcenter Nastran executable and input file, and Simcenter STAR-CCM+ constructs the full command for launching Simcenter Nastran for co-simulation (see Simcenter Nastran Launch Command Reference). This option is available when the Simcenter Nastran Launcher link model is active.	Simcenter Nastran Input File Specifies the location and name of the Simcenter Nastran input file (.dat file). You can either enter the full path or click and navigate to the file using the file selection dialog. Simcenter Nastran Executable Specifies the path to the Simcenter Nastran executable. You can type the full path manually or you can click and navigate to the executable using the file selection dialog. SimcenterMP Options Allows you to specify additional arguments for `SimcenterMP` (see Simcenter Nastran Launch Command Reference).
Launch Application via Command Line Simcenter STAR-CCM+ automatically launches the Simcenter Nastran simulation when you run the co-simulation. With this option, you manually enter the full command for launching Simcenter Nastran for co-simulation.	Launch Command Line Allows you to type the full launch command. See Simcenter Nastran Launch Command Reference.

Connect Option

As Simcenter Nastran couples with Simcenter STAR-CCM+ through the Simcenter STAR-CCM+ co-simulation API, the available options are the same as in a co-simulation between two Simcenter STAR-CCM+ simulations. For more information, see the Connect Option for Simcenter STAR-CCM+ to Simcenter STAR-CCM+ co-simulation.

Concurrency Mode

For co-simulation with Simcenter Nastran, the only compatible mode is Lag. When you launch the co-simulation, Simcenter Nastran runs first and Simcenter STAR-CCM+ waits for initial data.

Coupling Negotiation Option

Specifies the method for setting the coupling time interval, that is, the time interval between data exchanges.

The coupling time interval is the same in both simulations. You only specify the coupling time interval in Simcenter STAR-CCM+. SimcenterMP automatically sets the coupling time interval in Simcenter Nastran based on the Simcenter STAR-CCM+ settings.

The following methods are available:

Method	Corresponding Value Nodes
Matched Coupling Time The simulations exchange data at a time interval that you specify.	Transfer Interval Specifies the time interval at which the simulations exchange data. Make sure that you enter a value that is equal to or greater than the simulation time-step.
Time-Step The simulations exchange data at a time interval equal to the Simcenter STAR-CCM+ simulation time-step.	Transfer Interval Displays the time interval at which data is exchanged. Read-only.

Time-Step Adjustment Option

Specifies how Simcenter STAR-CCM+ adjusts the simulation time-step when the remaining time to the next coupling point is not an exact multiple of the simulation time-step. For more information, see Time-Step Adjustment Option for Simcenter STAR-CCM+ Co-Simulation.

Mapping Option

For co-simulation with Simcenter Nastran, the only compatible option is Map Both Directions. With this setting, Simcenter STAR-CCM+ maps the fields on import and export.

Disconnect Option

Allows you to specify whether the simulation disconnects or stays connected to the partner when the co-simulation is complete.

Verbosity Level

Allows you to choose the solver verbosity, that is, the amount of information that is printed to the Output window.

External Continua

Allows you to select the external physics continuum that represent the physics in Simcenter Nastran.

Co-Simulation Progression

Displays the current stage in the co-simulation.

Connection to Partner Simulation

Displays the state of connection between the simulations.

Zones Manager Properties

Number of Zones: Displays the number of zones defined for this link. Read-only.

Zones Manager Right-Click Actions

New: Adds a co-simulation zone under the Zones node.

[Zone] Properties

Index: Specifies a unique index which identifies a zone. Read-only.
Zone Type: Specifies what type of Simcenter STAR-CCM+ objects are assigned to the co-simulation zone for coupling. In co-simulation with Simcenter Nastran, the only available option is Surface Zone.

[Zone] Conditions and Values

The conditions and values of a co-simulation zone allow you to specify the Simcenter STAR-CCM+ coupled boundaries and the fields that are exchanged during the co-simulation.

Coupled Model Parts: Displays the Simcenter STAR-CCM+ boundaries that exchange data with Simcenter Nastran through this co-simulation zone. This property is read-only. To assign a model part to a co-simulation zone, use the External Code Coupling Specification condition for the relevant boundary.
External Model Parts: Read-only. When you run the co-simulation, this property displays the Simcenter Nastran surfaces that couple with the Coupled Model Parts assigned to this co-simulation zone.
Exported Fields, Imported Fields: These nodes specify the fields that are exchanged during the co-simulation. For more information, see Exchanged Fields Reference.
Export Mappers, Import Mappers: Simcenter STAR-CCM+ adds a mapper control for each of the fields that are selected for export or import. Each mapper control allows you to select the data mapper that maps the field to/from the partner simulation. You can choose between the default co-simulation mapper that Simcenter STAR-CCM+ creates automatically, or any custom mapper available under the Tools > Data Mappers node.

Link Right-Click Actions

Create New Zone: Allows you to create a new zone within an existing link.