System Coupling User's Guide

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Introduction to the System Coupling User's Guide

System Coupling Overview

The Ansys Product Improvement Program

Coupled Analysis Licensing Requirements

System Coupling Capabilities

Supported Coupling Participants

Ansys Electronics (Electronics Desktop/Maxwell)

Functional Mock-Up Unit (FMU)

Differences between FMU and Ansys Participants
Supported System Coupling Functionality

Mechanical/Mechanical APDL

Thermal Desktop

Participant Variables and Quantity Types Supported by System Coupling

System Coupling Capabilities

System Coupling's User Interfaces

System Coupling Contexts: GUI, CLI, and Workbench

Overview of System Coupling's Graphical User Interface (GUI)

System Coupling GUI Components

Menu Bar
Toolbar
Outline
Properties
Tabs
Status Area

System Coupling GUI Messages and Icons

System Coupling GUI Menus

Menu-Bar Menus
Context Menus

System Coupling Command-Line Interface (CLI)

Getting Help in the System Coupling CLI

Steps of a System Coupling Analysis

System Coupling Analysis Types

Steady Analysis Type
Transient Analysis Type

The System Coupling Data Model

Data Model Structure
System Coupling Settings

Units in System Coupling

Unit Conversions

Unit Syntax

Unit Multipliers

Commonly Used SI Units

SI Base Units
SI Data Transfer Quantity Units
SI Derived Units

Commonly Used Non-SI Units

Migrating to Ansys System Coupling 2025 R2

Migrating Across Multiple Releases

Migrating Command-Line System Coupling Scripts

Changes to the Data Model
Changes to Commands

Known Issues and Limitations

General
Parallel Processing
Units
Graphical User Interface
Participants
Data Model
Workbench
Postprocessing in EnSight

Starting System Coupling

Starting the System Coupling GUI

Starting the GUI from the Start Menu
Starting the GUI from the Command Line

Starting the System Coupling CLI

Startup Options

General Command-Line Options
Debug Logging Command-Line Options
System Coupling Parallel Options
Coupling Participant Parallel Options

Preparing for a Coupled Analysis

Setting Up a Coupled Analysis Directory Structure
Completing Participant Setups
Additional Participant Setup Considerations
Generating Participant Files

Setting Up a Coupled Analysis

Adding Participants

Adding a Participant in the GUI
Adding a Participant in the CLI
Adding a Functional Mock-Up Unit (FMU) Participant
Adding a Functional Mock-Up Unit (FMU) Proxy Participant

Adding a Coupling Interface

Rules for Adding Coupling Interfaces

Adding a Coupling Interface in the GUI

Adding a Coupling Interface in the CLI

Adding Data Transfers

Rules for the Creation of Data Transfers

System Coupling's Data Transfer Process

Adding a Data Transfer

Adding a Single Data Transfer
Adding a Data Transfer Group in the GUI

System Coupling's Mapping Capabilities

Mapping Types
Mapping Topologies
Region Discretization Types

Changing Data Model Settings

Viewing Data Model Contents

Viewing a Container's Contents
Viewing an Object's Children
Viewing the Contents of an Object's Children

Changing Data Model Values in the GUI

Changing Data Model Values in the CLI

Expressions in System Coupling

Expression Definition

Expression Evaluation

Expression Validation

Expression Values

Expression Definitions

Variables in Expressions

Mathematical Operators, Constants, and Functions

Conditional and Boolean/Logical Statements

Units in Expressions

Python Expression Functions

Expression Function Definition, Validation, and Evaluation
Defining an Expression Function
Adding an Expression Function
Reloading Expression Function Modules

Named Expressions

Reduction Expressions

Using Expressions to Set Data Model Values

Creating an Expression for an Immutable Single Value

Identifying Valid Expression Variables for Mutable Values

Creating an Expression for a Mutable Time Step Size

Creating an Expression for a Data Transfer Source Variable

Creating an Expression for a Data Transfer Source Variable in the GUI
Creating an Expression for a Data Transfer Source Variable in the CLI

Built-In Variables

Solving a Coupled Analysis

Starting the Solution

Monitoring Solution Progress

Terminating Participant Processes

Participant Solution Sequencing

Coupled Analysis Management

Inter-Process Communication
Convergence Management
Evaluating Convergence of Data Transfers

Postprocessing a Coupled Analysis

Reviewing Convergence Diagnostics Charting Output

Core Charting Functionality
Chart Tab Context Menu
Viewing the Convergence Diagnostics Chart
Viewing Data Transfer Quantity Diagnostic Charts
Writing Charting Diagnostics to CSV Files

Postprocessing Coupling Results in EnSight

Types of EnSight Postprocessing Files

Postprocessing with EnSight Gold Results

Changing Settings for Auto-Generating EnSight Gold Results

Generating EnSight Gold Results on Demand

EnSight Gold Postprocessing for Restarts

Loading EnSight Gold Results into EnSight

Loading EnSight Gold Results from the GUI
Loading EnSight Gold Results from the CLI
Loading EnSight Gold Results with EnSight Startup
Opening EnSight Gold Results in an Existing Instance of EnSight

Reviewing Results in EnSight

Parts
Geometry Transformations and Instancing in EnSight Results
Variables
Graphics Window

Postprocessing with EnSight Live Visualization Results

Adding a Live Visualization Object
Enabling Live Visualization
Selecting the Live Visualization Viewer
Running a Co-Simulation with Live Visualization
Activating the EnSight DVS Reader

Setting Up the EnSight Interface

Setting Up the Graphics Window
Setting Up the Viewports
Turning Off the Continuous Palette Setting

Working with Variables in EnSight

Variable Naming Conventions

Selecting Variables

Using Mapping Variables

Mapping Type Applicability
Mapping Variable Display

Visualizing Variable Data

Adjusting Plot Palette Ranges

EnSight Quick Reference

Adding a Text Annotation
Running a Simple Animation of Solution Time Steps
Adding a Simple Coordinate Probe
Adding a Time Annotation
Plotting Nodal Displacement as a Function of Time
Adding Force Vector Arrows

Common Coupled Analysis Tasks

Saving a Coupled Analysis

Working with Coupled Analysis Snapshots

Creation of Snapshots
Saving a Snapshot
Overwriting an Existing Snapshot
Printing a List of Available Snapshots
Opening a Snapshot
Deleting a Snapshot

Opening a New Working Directory from the GUI

Reconnecting the GUI to a Running Coupled Solution

Prerequisites
Disconnecting from the Running Solution
Reconnecting to the Running Solution

Stops and Restarts of System Coupling Analyses

Stopping a Coupled Analysis

Stopping a Coupled Analysis in the GUI
Stopping a Coupled Analysis in the CLI

Restarting a Coupled Analysis

Creation of Restart Points
Restarting a Coupled Analysis in the GUI
Restarting a Coupled Analysis in the CLI

Advanced Coupled Analysis Tasks

Defining Geometry Transformations for Models with Different Orientations

Adding Reference Frames
Adding Transformations
Using Automatic Interface Alignment
Defining Transformations for a Coupling Interface Side

Defining Interface Instancing for Cylindrical Geometry Models

Adding Instancing Objects
Defining Instancing for a Coupling Interface Side

Setting a Participant Connection Timeout Interval

Using Interactive Solve Commands

Simultaneous Execution of Participant Solutions

System Coupling's Participant Grouping Process
Enabling Simultaneous Participant Solutions
Execution of Simultaneous Participant Solutions
Simultaneous Participant Solution Examples

Using Parallel Processing Capabilities

Recommended Workflow for Parallel Execution

Parallel Processing for Coupling Participants

Machine List and Core Counts

Resource Allocation Fractions

Partitioning Algorithms

Choosing a Partitioning Algorithm

Partitioning Algorithm Pros and Cons

Participant Partitioning Examples

Shared Parallel: Allocate Machines
Shared Parallel: Allocate Cores
Distributed Parallel: Allocate Cores
Distributed Parallel: Allocate Machines
Custom Partitioning Examples

Applying Partitioning to Coupling Participants

Applying Participant Partitioning in the GUI

Applying Participant Partitioning in the CLI

Applying Custom Participant Partitioning

Partitioning Information
Getting Lists of Available Participants and Machines
Applying Custom Partitioning by Running a Command
Applying Custom Partitioning in the GUI
Applying Custom Partitioning by Running a Script

Parallel Options for System Coupling

Parallel Options for Participant Products

Adding Solver-Specific Parallel Arguments

Using AEDT HPC Distribution Options

Using Automatic HPC Distribution Options
Using Manual HPC Distribution Options

Using Job Schedulers with System Coupling

Using the LSF Job Scheduler
Using the PBS Job Scheduler
Using the UGE Job Scheduler
Using the SLURM Job Scheduler

Parallel Execution Example

Running an Exported System Coupling Setup

Running an Exported Partial Setup
Running an Exported Full Setup

Requesting Debugging and Diagnostic Output

System Coupling Input and Output Files

Files Used by System Coupling

Participant Setup File

<ExecutionControl>

<InitialInput>
<Command>

<CosimulationControl>

<Dimension>

<AnalysisType>

<DisplayName>

<RestartsSupported>

<Variables>

<Name>
<DisplayName>
<QuantityType>
<TensorType>
<IsExtensive>
<Location>

<Parameters>

<Parameter>

<Name>
<DisplayName>
<TensorType>

<InputParameters>

<Parameter>

<OutputParameters>

<Parameter>

<DisplayName>

<OutputVariables>

<Variable>

<InputVariables>

<Variable>

Sample System Coupling Participant File

<Transfers>
<ExecutionControl>
<Analysis>
<Participants>

Shutdown File

Files Generated by System Coupling

GUI Server File

Solution Lock File

Transcript and Log File

Summary of Coupling Setup

Library
Coupling Participants
Analysis Control
Coupling Interfaces
Solution Control
Output Control
One-Way Workflow Message
Pre-Solution Warnings and Messages
EnSight Output Display Name Modifications
Partitioning Information
Execution Information
Build Information

Analysis Initialization

Mesh Statistics
Mapping Summary
Reference Frame and Instancing Information
Transfer Diagnostics

Coupled Solution

Coupling Step

Explicit to Implicit Solver Coupling
Mapping Summary
Coupling Iteration

Available Restart Points
Timing Summary

Settings File

Restart Files

Export Setup Log File

Ansys EnSight Results Files

Server File

Process Cleanup Script

Common Engineering Applications for System Coupling

Fluid-Structure Interaction (FSI)

Building a Coupled FSI Analysis from Decoupled Participant Problems

Step 1: Solve the Fluid and Structural Problems Independently
Step 2: Solve the Fluid and Structural Problems as One-Way Coupled Analyses
Step 3: Solve the Fluid and Structural Problems as a Two-Way Coupled Analysis

Choosing the Mesh-Related Timescale

Defining Mesh Motion and Deformation Settings

Aerodynamic Damping Analysis

Coupling Participants

Verify Coupling Participant Input Files

Add Coupling Participants

Define the Mechanical Server

Define the CFD Server

Set Execution Control Parameters
Define Participant Instancing

Coupling Interfaces

Add a Coupling Interface
Add Data Transfers
Using Expressions

Handling Participant Setup Changes

Performing Mapping

Verifying Mapping Results

Review the System Coupling Transcript
Visualize Mapped Results in EnSight

Improving Mapping Results

Performing Remapping

Using Mapping Results

Electric Arc Modeling

Coupling Participants

Setting Up Coupling Participants
Adding Coupling Participants

Coupling Interfaces

Adding a Coupling Interface
Adding Data Transfers

Solving the Analysis

Monitoring and Postprocessing

Using System Coupling in Workbench

Overview of System Coupling in Workbench

Supported Coupling Participants for System Coupling in Workbench
Data Transfers for System Coupling in Workbench
Steps of a Coupled Analysis in Workbench
System Coupling Tab in Workbench

Setting Up a Coupled Analysis in Workbench

Creating a Coupled Analysis

Completing Participant Setups

Connecting Systems on the Project Schematic

Completing the Coupling Setup

Setup Node Context Options

Coupling-Specific Properties

Analysis Settings

Analysis Type
Initialization Controls
Duration Controls
Step Controls

Participants

Regions

Data Transfers

Source/Target
Data Transfer Control
Data Transfer Context Options

Execution Control

Coupling Engine
Expert Settings
Intermediate Restart Data Output

Running a Coupled Analysis in Workbench

Starting the Solution

Monitoring Solution Progress

Viewing Transcript Output

Viewing System Coupling Charts

Availability of Chartable Data

Chart Properties

Chart Variables

Adding a Chart Variable
Chart Variable Properties

Chart Context Options

Chart Monitor Controls

Saving a Chart as a Graphic

Solution Validation and State

Solution Node Context Options

Common Tasks for System Coupling in Workbench

Stopping a System Coupling Analysis in Workbench

Restarting a Coupled Analysis in Workbench

Generating Restart Files in Workbench
Restarting a Coupled Analysis in Workbench
Recovering from a Workbench Crash

Advanced Tasks for System Coupling in Workbench

Requesting Debugging and Diagnostic Output

Requesting Debug Log Files

Exporting a System Coupling Setup

Steps to Create the System Coupling Setup
Files Needed for a User-Interface Run
Exporting Partial vs. Full Coupling Setups
Exporting the System Coupling Setup

Generating Participant Solver Input and Coupling Setup Files On Demand