Computational Fluid Dynamics (CFD) modelling software
Helping industries design safer facilities, optimise safety measures, and meet regulatory standards with precision and confidence.
FLACS is a leading CFD tool built for safety professionals to predict and mitigate the consequences of fires, explosions, and toxic gas dispersion.
By leveraging detailed 3D modelling, FLACS supports engineers and decision-makers in identifying risks, optimising facility layouts, and developing effective safety strategies in complex industrial environments.
FLACS supports the design and operation of safer industrial facilities, protecting lives, assets, and the environment.
By replicating real-world hazard scenarios, it delivers actionable insights that empower engineers to reduce risks and ensure compliance with industry standards.
- Accurate modelling for complex 3D geometries
- Trust results built on 40+ years of research
- Detailed outputs for safer, smarter decisions
- See hazards clearly, communicate effectively
User-friendly interface
Engineered for simplicity, allowing safety professionals to solve problems efficiently without steep learning curves.
Scenario-based modelling
Simulate diverse hazard scenarios to assess risks, explore ‘what-if’ situations, and develop optimised mitigation strategies.
Validated results
Trusted by experts globally, with outputs aligned to experimental and real-world data.
Energy transition ready
Built to address emerging safety challenges in hydrogen, ammonia, carbon capture, and renewable energy systems.
Validation example
See how FLACS compares against experiments from the HySEA project, which focused on vented deflagrations in enclosures and containers for hydrogen energy applications.
“A study using traditional prescriptive methodology recommended installing over 50 detectors in an onshore gas compression plant. A study performed by Gexcon using FLACS demonstrated that installing 18 detectors would meet all the required specifications.”
Anonymous
Oil and Gas Company
Announcements
FLACS 25.4 is now live
FLACS 25.4 focuses on improving workflow quality, model behaviour and overall performance across the software, with a strong emphasis on how users run and manage large, study-based simulation work in practice.
Gexcon announces FLACS 25.3 release with enhanced accuracy, speed, and workflow efficiency
FLACS 25.3 enhances flammability predictions, reduces simulation time, and improves geometry handling to support reliable hazard modelling.
Next events:
Insights
FLUG Norway 2024: My key takeaways and reflections
Gexcon VP Products Chris Coffey, shares his highlights on the 2024 FLUG meeting held in Bergen on the 24-25 September.
LNG facility siting: The benefits of using advanced modelling tools in your study
How advanced modelling tools can help improve LNG facility siting by supporting safer and more practical decision-making.
Consequence analysis: 10 things to consider before performing your study
Consequence analysis is a critical aspect of process safety and risk management. Here are 10 crucial considerations to ensure a successful analysis.
Hydrogen bulk storage areas: How advanced consequence modelling can inform a safer design and help reduce the risks from explosions
Advanced modelling tools can analyse the consequence of explosions in hydrogen bulk storage areas hence assisting in creating a safer design.
Piper Alpha: 34 years of explosion modelling software development
The development of Gexcon’s industry standard software for dispersion, explosion and fire modelling is closely linked to Piper Alpha.
Battery Thermal Runaway Consequence Modelling with the X-Suite
Learn how to model BESS thermal runaway hazards using Gexcon’s X-Suite tools with practical guidance, workflows, and a practical case study.
Optimising gas detection layout using CFD
Learn how CFD technology can optimise gas detection layouts to improve safety and achieve cost savings over time
Assessing indoor gas release scenarios to support safer facility design with X-Suite
Learn how to assess the consequences of indoor gas releases using advanced modelling — and understand when to use integral or CFD model.
Evaluating water spray systems for ammonia release mitigation using FLACS CFD
This webinar explains how the dynamic water spray model in FLACS CFD enables realistic simulation of water spray systems, including droplet–gas interaction and ammonia absorption.
Modelling battery hazards for safer operations
Learn about lithium-ion battery risks, failure scenarios, and how advanced modelling supports safer and more reliable operations.
New in FLACS 25.2 – Modelling water spray and inerting systems
This webinar provides an overview of the new features and improvements introduced in FLACS 25.2.
Ammonia hazard modelling
Learn the basics of ammonia hazard modelling and how advanced modelling tools can help assess the risks and consequences of ammonia releases.
Frequently asked questions
FLACS is an advanced CFD software purpose-built for industrial safety applications. It specialises in modelling complex hazard scenarios in large-scale 3D environments, providing essential tools for understanding gas dispersion, explosion overpressures, shockwave propagation, and fire dynamics.
Originally developed in Norway at the Christian Michelsen Institute, FLACS has evolved into a versatile solution for safety design and optimisation across industries, including traditional oil & gas and emerging renewable energy sectors.
FLACS addresses a wide range of industrial safety challenges, including:
- Modelling gas, dust, or vapour explosions with accurate consideration of geometries.
- Simulating toxic gas dispersion and optimising evacuation strategies.
- Designing fire and gas detection layouts for industrial facilities.
- Optimising facility layouts to mitigate risks from fires, explosions, and toxic releases.
- Evaluating hydrogen, ammonia, and cryogenic releases for energy transition projects.
- Smoke modelling to understand escape route impairment and ventilation system performance.
- Conducting quantitative risk assessments to meet regulatory requirements.
FLACS provides a comprehensive range of results to support detailed safety assessments and decision-making. Key outputs include:
- Gas dispersion: Concentration levels and dispersion patterns for toxic or flammable gases over time and distance.
- Explosions: Overpressure levels, impulse distributions, and shockwave propagation through complex environments.
- Fires: Flame dimensions, thermal radiation profiles, and heat flux distributions.
- Ventilation: Flow rates and air distribution in confined or ventilated spaces.
These results can be visualised and explored interactively within Flowvis, FLACS’ dedicated post-processing tool, allowing you to analyse 2D and 3D plots, contours, and dynamic simulations for deeper insights.
Additionally, FLACS supports integration with external workflows through a robust Python API, enabling users to automate data extraction, customise analysis processes, and integrate results into broader engineering and risk management systems.
This flexibility allows engineers to explore data in detail, compare multiple scenarios, and generate actionable insights for safer facility design and operations.
FLACS offers flexible licensing tailored to your organisation’s needs, including standalone, network, and cloud-based options. Licences are available for varying durations. Contact our team to find the solution that works best for you.
FLACS supports 64-bit versions of Windows and Linux operating systems, tested on Windows 10 Pro and Ubuntu 18.x.
For full compatibility details, view the FLACS Technical Requirements document or contact our technical team for assistance.
Access our Knowledge Base for detailed guides, including software configuration, feature overviews, and step-by-step use cases. Additionally, we offer training programs tailored to your needs:
- Introductory courses: Learn to effectively use FLACS in your safety projects.
- Advanced courses: Gain deeper insights into specialised scenarios.
- Customised training: Tailored sessions to address your organisation’s specific challenges.
Explore additional resources such as blog articles and on-demand webinars to enhance your expertise.
Would you like to know more about FLACS?
See how FLACS can improve hazard modelling accuracy, support smarter decisions, and optimise safe designs.
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