Experimental data and CFD performance for CO2 cloud dispersion analysis

Dispersion of hazardous gas releases represents a major threat to health and to the environment; therefore, the prediction of the dispersion features raises great interest. In recent years, with the increase in computational capacity, the interest in Computational Fluid Dynamics (CFD) tools to evaluate dispersion analysis has increased. With the growing use of CFD tools to perform dispersion analysis in different scenarios, it is imperative to amplify the availability of experimental data in order to allow validations studies to contribute to understanding the real capacity of CFD tools to properly represent real cases. The second stage of the field tests conducted by a joint venture between the University of São Paulo and the Universitat Politecnica de Catalunya was established to investigate the performance of CFD tools when analyzing cloud dispersion of hazardous substances by means of ad-hoc experimentation. The experiments consisted of CO2 clouds formation and dispersion tracking of releases of up to 0.85 kg s−1 of about 40 s of duration in a 600-m2discharge area. We provide a description of the tests and the main results of the simulation using the FLACS software; the peak concentrations for 51 sensors placed at the dispersion cloud path are provided here and compared with CFD simulations. In general terms, the CFD simulator presented good performance; all the statistical performance measures were well within the acceptable range. However, the simulator performance presented sensitivity to the wind profile, especially when cross wind occurs.