The dispersion models in FLACS are very accurate due to their extensive validatation against experimental data. The ability to include complex geometries along with a wide range of applicability should make FLACS a preferred CFD dispersion model for toxic or flammable dispersion studies at various scales.

GexCon can offer a wide range of ventilation and dispersion modeling studies using FLACS. The main advantage of using FLACS is to effectively incorporate complex geometries in the simulations. Various release sources can modeled in FLACS, which include high pressure gas, low pressure gas, liquified gases (flashing or pools), and spills of cryogenic liquids. Some examples of studies that GexCon can perform are:

  • Forced and natural ventilation, evaluation of air changes in the structure
  • Flammable gas dispersion and subsequent explosion modeling (if ignited)
  • Evaporating flammable and combustible liquids
  • Toxic gas dispersion (transportation accidents or storage tank failures)
  • Stack release disperson in low (or zero) wind
  • Exhaust gas studies, e.g. for helideck evaluations
  • Gas sensor optimization studies, including CO studies

Vapor cloud releases can be dynamically modeled to determine dispersion rates, concentration profiles (including flammable limits), in addition to chemical exposure limits for workers.  Below a plot sequence from a simulation study is shown, in which a massive chlorine release from a railcar is simulated in an urban area (Hanna, Atm. Env. 2009). More than 60 tons of chlorine were released over 5 minutes, pictures show 2000 ppm concentration 200s, 400s, 800s, 1500s and 2000s after start of release. Buildings and local terrain (e.g. river) had a strong influence on the dense gas dispersion. 

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