💥💥💥 What is ROM Builder in Ansys Workbench and what is it for?

 ROM Builder is a tool that allows you to create reduced order models (ROMs) from your computational fluid dynamics (CFD) simulations in Ansys Workbench. ROMs are simplified representations of complex systems that can capture the essential behavior of the system with much less computational cost. ROMs can be used for various purposes, such as design optimization, parameter studies, system simulation, digital twins, and real-time control¹.

To build a ROM, you need to run a number of design points through a solver. The results from these runs are then combined into a ROM using Ansys DesignXplorer’s 3D ROM builder. These ROMs can then be combined into a system simulation, or digital twin, using Ansys Twin Builder¹.

ROM Builder is available for Fluent systems in Ansys Workbench. You can set up and build a ROM by defining the input parameters, output variables, and design points in the ROM Builder component. You can also export the ROM in standard formats, such as FMU or ROMZ, that can be imported into other software tools².

If you want to learn more about how to use ROM Builder in Ansys Workbench, you can watch some video tutorials here, here, or here. You can also read some articles here, here, or here. I hope this helps you understand what ROM Builder is and what it is for. 😊

How to define ROM Builder for Ansys Fluent?

To define ROM Builder for Ansys Fluent, you need to follow these steps:

• Drag and drop a 3D ROM system from the Design Exploration toolbox in Workbench to your Fluent project¹.
• Define the input parameters that you want to vary in your ROM, such as boundary conditions, material properties, or operating conditions. You can do this in the Parameters tab of the ROM Builder component².
• Define the output variables that you want to capture in your ROM, such as forces, moments, heat transfer coefficients, or pressure drops. You can do this in the Variables tab of the ROM Builder component².
• Define the design points that you want to run for your ROM, using either a predefined or a custom design of experiments (DOE) method. You can do this in the Design Points tab of the ROM Builder component².
• Run the design points and generate the solution snapshots for your ROM. You can do this by right-clicking on the ROM Builder component and selecting Update².
• Build and evaluate the ROM using DesignXplorer’s 3D ROM builder. You can do this by right-clicking on the 3D ROM builder component and selecting Update².
• Export the ROM in a standard format, such as FMU or ROMZ, that can be imported into other software tools, such as Twin Builder².

Is ROM Builder only for Steady State Cases, what module do I need to use for Transient Simulations in Ansys Workbench ?

ROM Builder is only for steady state cases in Ansys Workbench. You cannot build ROMs based on transient analysis using ROM Builder¹. If you want to create ROMs for non-linear transient systems, you need to use Ansys Twin Builder. These types of ROMs are called Dynamic ROMs; Twin Builder has a Dynamic ROM builder to make the process very simple². You can find more information about Twin Builder and Dynamic ROMs in the Ansys Learning Hub - Systems - Twin Builder³. You can also watch a video on how Reduced-Order Models can be used in real-time here.