Plume dispersion, mixing and chemistry simulation using the Lagrangian Volumetric Particle Approach with realistic atmospheric chemical kinetics mechanisms

The Lagrangian Volumetric Particle Approach (VPA), introduced by Cassiani (2013), has been implemented within an operational Lagrangian Stochastic Particle Dispersion Model, which now includes a set of chemical kinetics equations for atmospheric chemistry. The model is coupled on-line with a grid-based Eulerian Chemistry Transport Model (CTM), which solves the same set of atmospheric chemical kinetics equations.

By employing the Lagrangian VPA, the high-order covariances arising from the averaging operator applied to the nonlinear chemical kinetics mechanisms are represented in closed form. This capability enables the VPA to model, with high accuracy, both the near-source turbulent dispersion and mixing as well as the impacts of atmospheric turbulence on highly nonlinear plume chemistry.

The integration with the Eulerian CTM allows the separation of background and plume chemistry using a plume-in-grid scheme. This advanced modeling system has been developed as part of the FuNitr project (Future Drinking Water Levels of Nitrosamines and Nitramines near a CO2 Capture Plant), which aims to investigate potential chemical transformations within plumes emitted by Carbon Capture and Storage (CCS) facilities.

Here, we present the modeling system alongside simulations of reactive plumes, incorporating a reduced but realistic atmospheric chemical kinetic mechanism.  Reference: Cassiani, M. (2013). The volumetric particle approach for concentration fluctuations and chemical reactions in Lagrangian particle and particle-grid models. Boundary-Layer Meteorology, 146(2), 207–233.