Effigy performs fire and gas mapping calculations in compliance with the ISA technical report ISA TR 84.00.07 Guidance on the Evaluation of Fire, Combustible Gas and Toxic Gas System Effectiveness.
Coverage can be calculated in one of two ways, Geographic or Scenario based.
When performing geographic coverage, the software will calculate the fraction of a geographic area or volume where fires or gas releases would be detectable.
For Scenario based coverage the software will calculate the fraction of fire or gas hazards that are detectable.
The Fire or Gas hazards of concern are defined by you as the user. These are referred to as scenarios in Effigy. For each scenario you are asked to provide a location and magnitude (size) of the consequence gas cloud. The magnitude of the hazard could come from the results of CFD modeling however, it is much more common to define this magnitude based on gaussian dispersion modeling using gaussian modeling software like Phast, EFFECTS or Canary.
Effigy software does not perform CFD or Gaussian modeling at this time.