Fire Dynamics Simulator Releases Version 6.11
Fire Dynamics Simulator is a widely used computer fire modeling tool developed by a team led by the National Institute of Standards and Technology. FDS uses computational fluid dynamics to predict smoke and heat transport from fires in the built environment and is widely used by fire researchers and fire protection engineers worldwide.
Contributing to the Development of FDS 6.11
UL Research Institutes’ Fire Safety Research Institute is pleased to support the continued development of FDS to better serve fire protection engineers, fire researchers, and designers of life safety systems. Through software development, as well as bench and large-scale experiments, ULRI’s fire safety team conducts ongoing FDS research to further its success.
On May 18, 2026, FDS 6.11 was released, introducing major changes, new features, and bug fixes. Key updates include:
- Flux limiter overhaul
- Mesh refinement with UGLMAT solver
- New mixing and chemistry formulation
- Total mass flux devices in the gas phase can be used without spec ID
- HVAC can now be used with geometry
- Added a bi-directional probe output, which models the output of a typical bi-directional probe correcting for Reynolds number and flow angle.
“With this release, all of the Verification and Validation scripts have been migrated to Python. We hope that moving to an open language like Python lowers the barrier for people to participate in and contribute to the FDS project.”
—Jason Floyd
Principal Research Engineer
UL Research Institutes | Fire Safety Research Institute
To access the full list of changes and additional information, visit the FDS Release Notes.
