Development of a numerical framework for modeling and reduction of plasma chemical kinetics

This thesis aims to extend numerical modeling techniques for non-equilibrium plasmas in order to simplify the study of complex plasma-chemical processes. In particular, it presents the development of a numerical solver for global models (SPPARK - Simulation Platform for Plasma Assisted Reactive Kinetics), based on the coupling of Cantera and Bolsig+, which provides an open-source framework to represent complex phenomena such as electron kinetics in non-equilibrium plasmas, reaction thermodynamics, and the interactions between these two domains. The solver also includes the capability to model heterogeneous phase phenomena, allowing the incorporation of interaction mechanisms of a plasma phase with electrodes and gas ones. In this context, the thesis introduces a multizone approach for the representation of systems that are not strictly spatially homogeneous. This approach consists of defining a separate system of ordinary differential equation for each phase and introducing transport derived net source terms in such equations, thereby enabling separate results for different phases while maintaining their coupling through the representation of transport processes. The overall goal is to obtain simulation results from complex reaction schemes that are less constrained by the assumption of homogeneity. This approach can provide useful and more detailed inputs for the final aspect addressed in the thesis: the adoption of Analytically Reduced Chemistry techniques in plasma-chemistry modeling. These techniques allow for the reduction of the chemical complexity associated with the reaction schemes used in numerical models. The simplification of detailed reaction mechanisms, with arbitrary and controllable accuracy, enables their adoption within geometrically resolved simulations, while keeping the computational cost contained. The thesis ultimately presents a comprehensive chemistry reduction framework, combining established methodologies with new approaches, that can deal with the reduction of arbitrary complex chemistry sets for non-equilibrium plasmas.