Reduction of chemical reactions in nitrogen and nitrogen-hydrogen plasma jets flowing into atmospheric air

The large number of possible chemical reactions represents a severe burden for modeling of even relatively simple plasma systems. Reduced sets of chem ical reactions have been obtained for numerical simulations of nitrogen and nitrogen-hydrogen plasma jets flowing into an atmospheric air environment. The important or active reactions are determined based on a simplified red uction method. A reaction is considered active if it leads to higher sensit ivities than a specified cutoff sensitivity of 1%. The active reactions exe rt a significant influence on main plasma parameters, such as velocity, tem perature, and species concentrations. The sensitivity analysis for the spec ified systems shows that two NO reactions, known as Zel'dovich reactions (N -2 + O <-> NO + N and NO + O <-> O-2 + N),((I)) are both active in a nitrog en plasma jet. On the other hand, the latter is not active and may be omitt ed in a nitrogen-hydrogen plasma jet. A nitrogen-hydrogen plasma jet requir es contribution of two active charge exchange reactions: N-2 + N+ <-> N-2() + N and N + H + <-> N + + H, while only the former is needed in a nitroge n plasma jet. The dissociation reactions are all active in both plasma jets , except the dissociation of OH.