SDF Technology

SCIPUFF Dispersion Model from L3-Titan

The SCIPUFF (Second-order Closure Integrated PUFF) model is a Lagrangian puff dispersion model developed by Titan's ARAP Group that uses a collection of Gaussian puffs to represent an arbitrary, three-dimensional time-dependent concentration. The turbulent diffusion parameterization is based on turbulence closure theory, providing a direct relationship between the predicted dispersion rate and turbulent velocity statistics of the wind field. In addition to the average concentration value, the closure model also provides a prediction of the statistical variance in the concentration field resulting from the random fluctuations in the wind field. The closure approach also provides a direct representation for the effect of averaging time. SCIPUFF has been incorporated into the Defense Threat Reduction Agency's (DTRA) Hazard Prediction and Assessment Capability (HPAC) software. HPAC is utilized for planning and analysis as well as in the field by military personnel to rapidly determine consequences of dispersing chemical, nuclear and biological agents. SCIPUFF has been validated against a number of laboratory and field experiments, demonstrating its usefulness for non-military applications. It has been recommended as an alternative model by the EPA which can be used on a case-by-case basis for regulatory applications. The publicly available version of SCIPUFF is the same version incorporated in HPAC except that the proprietary and developmental features have been disabled. SCIPUFF runs on a PC with a user-friendly Graphical User Interface (GUI).

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