Oklahoma City Contaminant Dispersion: Concentration Data Processing and Analysis for a Scaled Puff Release Experiment

Abstract

Magnetic resonance techniques were leveraged to obtain velocity and concentration measurements for a puff release contaminant dispersion study. The study involved a scaled model of downtown Oklahoma City as it was in 2003, and sought to provide a high fidelity, three-dimensional data set for comparison with JU2003 and subsequent studies. The scaled model was placed in a water channel with fully turbulent flow (Re = 36,000), and an MRI system was used to take scans at 12 time-specific measurement phases throughout the puff injection cycle. The present work details processing methods applied to the nearly 650 million magnetic resonance concentration (MRC) data points obtained from the study. Processing entailed the calculation of a concentration field through background subtraction and normalization involving several distinct scan types. Uncertainty was reduced through the scaling and combination of high molarity scans. Processing methods are followed by a preliminary investigation of the results, which highlights noteworthy elements of scalar transport within the data set and the need for further investigation of the complex flow field. The study ultimately demonstrates the applicability of magnetic resonance techniques to puff release and dynamic experimental conditions, as well as a method for working with data from phase-locked experiments.