Study on along-wind dispersion coefficient of natural gas highly containing carbon dioxide

In order to study the characteristics of puff dispersion, observations of along-wind dispersion of puff comprised by natural gas highly containing carbon dioxide were collected from computational fluid dynamics(CFD) simulation and were used to develop similarity relations. Because the observations consist of the concentration time series from fixed samplers, the basic observed variable is σ_t, the standard deviation of the concentration time series. The concentration time series observation also allow the travel time t from source to receptor to be estimated, from which the puff speed u_e can be determined. The along-wind dispersion coefficient σ_x is then calculated from u_e · σ_t. The resulting σ_x observations support the similarity relations σ_x =813.47x^-0.47 where x is distance from the source to the sampler. The present similarity relationships certainly account well for the characteristic features of instantaneous dispersion of natural gas highly containing carbon dioxide and can be utilized for providing guidelines for emergency response measures.