MODELLING POLLUTANT REACTIONS DEPENDING ON INSTANTANEOUS CONCENTRATIONS: A DIRECT ESTIMATION OF THE SEGREGATION COEFFICIENT

We have implemented a reaction scheme, based on the conserved scalar theory, into a Lagrangian micromixing model (LAGFLUM, Leuzzi et al.). This coupled solution is tested in decaying grid turbulence to represent the dispersion of reactive pollutants. We report preliminary validations, obtained by comparisons with available measurements and analytical solutions, as well as several model inter-comparisons. We underline the difference between modelling pollutant reactions depending on the instantaneous instead of the mean concentrations of the reactants (effects of the segregation coefficient). Finally, we have implemented and tested a new limit for the scalar conserved theory, which tries to improve the reaction-dominated limit (RDL) in non-homogeneous conditions.