The latest software version

Gexcon is pleased to introduce FLACS 26.1, a release focused on improving day-to-day workflow, reliability, and efficiency across the product. The primary focus of this release is Multiscenario, with meaningful improvements to autogrid inspection, bulk editing, and the handling of larger scenario sets. These updates are accompanied by broader usability and reliability improvements spanning geometry import, the Python API, Flowvis, FLACS Cloud, and FGC.

Key improvements

• Multiscenario is strengthened as a core workflow, with better tools for inspecting autogrid quality, bulk editing of items, and more reliable handling of larger scenario sets

• Broader Multiscenario usability improvements make day-to-day setup and review easier, including resizable table columns, improved property display, and smarter node tree navigation

• Reliability improvements across geometry import, the Python API, and FLACS Cloud make workflows more robust and consistent

• Flowvis gains faster CGNS loading and a new turbulent burning velocity output

• FGC correction to area porosity handling, which may slightly affect results

• Linux support baseline updated — RHEL 8 / GLIBC 2.28 is now the minimum requirement

Simulators

• Bug fixes: FLACS-CFD 26.1 resolves several edge-case bugs in the core simulators, which can affect specific fire, pool, and dispersion results.

• Monitor region descriptors: Allow special characters in monitor region descriptors.

• Allow reduced 1d output frequency: (MOD_TIME_1D) to manage file sizes.

• Monitor region variables: for equivalent gas cloud tracking (FuelMass, GasMass, FlamMass, FlamVol, and ERfacMass) previously limited to dispersion scenarios, are now available under reacting conditions (post-ignition explosion and fire).

• Default gas monitor region: Zero-sized and out-of-domain default gas monitor regions are now reset to the full domain. If the Gas monitor region is checked in CASD with SIZE left at zero. This can affect steady state simulation convergence (see convergence tolerance section in the manual).

Multiscenario

This release delivers significant improvements to Multiscenario, making it a more capable and scalable way to manage large simulation studies in FLACS.

• Improved autogrid quality inspection — new tools for verifying and inspecting autogrid quality make it easier to review grid setup before committing to large exports.

• Autogrid constraint weights — support has been added for autogrid constraint weights in Multiscenario workflows, offering greater control over grid generation.

• Bulk modification of items — users can now select and modify multiple monitor points, leaks, and other items simultaneously, reducing repetitive setup work on larger scenario sets.

• Improved export reliability — fixed export failures and various UI issues related to porosity calculations, progress dialogs, and licence server errors when exporting a large number of scenarios.

• Enhanced table and property editor usability:

  • Resizable column widths, with persistence between sessions

  • Improved property display in table view

  • Automatic expansion of the node tree when the active node changes

• Improved file handling on Windows, with added support for hard links and symbolic links.

Geometry

Reliability improvements have been made to DWG file import in geo2flacs, reducing the likelihood of missing or incorrectly rendered geometry when working with CAD source files.

• Fixed missing geometry on DWG import — resolved issues where importing DWG files could result in geometry being dropped in geo2flacs.

• Improved import of DWG solids — a broader range of solid types are now handled correctly on import.

• Fixed incorrect colours on DWG import — corrected a display issue affecting colour assignment for some DWG files.

Python API

Two fixes improve the robustness and predictability of Python API behaviour, particularly for users running automated or batch workflows.

• Fixed hidden dependency in dataset.scenario() — resolved an issue where scripts could fail silently depending on the Python environment in which they were run.

• Autogrid threshold values now respected by the API — threshold values defined in configuration files are now correctly applied when accessed through the Python API, ensuring consistency between UI and scripted workflows.

Flowvis

Flowvis receives both a performance improvement and a new analysis output in this release.

• Turbulent burning velocity output (TURBSS / sturbvel) — turbulent burning velocity is now available as an output variable in Flowvis.

• Faster CGNS file loading — CGNS files now load more quickly in Flowvis, reducing wait times when working with large simulation outputs.

• Fixed incorrect colours in 3D plot visualisations — resolved a colour rendering issue affecting certain 3D plot types.

FLACS Cloud

Stability and reliability improvements have been made to FLACS Cloud, addressing issues that could affect users managing active simulation jobs.

• Fixed crashes on simulation abort and folder deletion — resolved crashes that could occur when aborting simulations and deleting folders before reconnecting to the cloud.

• Improved Download all files reliability — the Download all files functionality now ensures consistent retrieval of all job files from FLACS Cloud, reducing the risk of incomplete downloads.

RunManager

A new control has been added to RunManager, giving users more flexibility over porosity handling in their simulation runs.

• Option to disable Enhanced Smart Porosity — users can now explicitly disable Enhanced Smart Porosity from within Runmanager.

FGC

• A bug fix has been applied to area porosity handling in FGC. This correction may produce slightly different results compared to previous versions.

Linux system requirements

The minimum supported Linux environment has been updated. Users running older Linux distributions will need to upgrade before installing FLACS 26.1.

• Minimum Linux requirement is now RHEL 8 compatible, GLIBC 2.28 — this reflects updated system library dependencies.

• The following distributions are no longer supported: CentOS/RHEL 7, Ubuntu 18, Debian 9.

Get access to 26.1

Existing users can download the new software update by clicking on this link.