Verification

ASTM E1355 Standard Guide for Evaluating the Predictive Capability of Deterministic Fire Models (2018) defines model validation as “the process of determining the degree to which a calculation method is an accurate representation of the real-world from the perspective of the intended uses of the calculation method.”

ASTM E1355 Standard Guide for Evaluating the Predictive Capability of Deterministic Fire Models (2018) defines model verification as “the process of determining that the implementation of a calculation method accurately represents the developer’s conceptual description of the calculation method and solution to the calculation method.” Slightly different definitions of model verification are used by other standards in other industries, but in general verification involves assessing whether the underlying mathematical formulation is correctly implemented in the source code - or “is the math right”.

Model verification is typically approached by simulating simple canonical problems and comparing model outputs to exact solutions, where available. ELMFIRE has been subjected to extensive model verification exercises since development began in 2010. In an effort to promote transparency and authenticity, ELMFIRE’s mathematical formulation is documented in the Technical Reference, its source code is maintained in a public Git repository, and several model verification test cases are presented below (with associated scripts and inputs available in the Git repo).

• Verification Case 01: Elliptical fire shape
• Verification Case 02: Crown Fire