Validation and Sensitivity Study of the PMSS Modelling System for Puff Releases in the Joint Urban 2003 Field Experiment

Abstract

The Joint Urban 2003 (JU 2003) experimental campaign took place in downtown Oklahoma City, Oklahoma, USA, comprising both continuous and puff releases of sulphur hexafluoride (SF6) tracer gas. In the framework of the UDINEE project, intensive operation period 8 (IOP 8) conducted during the night is simulated using the Parallel-Micro-SWIFT-SPRAY (PMSS) three-dimensional modelling system. The PMSS modelling system is the assembly of a diagnostic or momentum flow solver (PSWIFT) and a Lagrangian particle dispersion model (PSPRAY) accounting for buildings and developed in parallel versions. A sensitivity study is performed regarding the flow modelling options, namely the meteorological data input, the characteristics of the turbulence, and the use of the diagnostic or momentum solver. Results shed light onto issues related to modelling puff releases in a built-up environment. Flow and concentration results are compared to measurements at the sample locations in IOP 8 and statistical metrics computed for all puffs released during IOP 8. These indicators illustrate satisfactory performance and robustness of the PMSS system with reference to the modelling options. Moreover, with moderate computational times and reliable predictions, the PMSS modelling system proves to be relevant for emergency response in cases of atmospheric release of hazardous materials.