In this work, a novel 0D model for the evaluation of O₃ and NO₂ produced by a surface dielectric barrier discharge (SDBD) in a closed environment is presented. The model is composed by two coupled sub-models, a discharge sub-model and an afterglow one. The first one, simulating the discharge regime and consequently including electron impact reactions, aims to calculate the production rates of a set of key species (atomic oxygen, excited states of molecular oxygen and molecular nitrogen). These latter are the input of the afterglow sub-model, that simulates the afterglow regime. We introduce a methodology to relate the production rates of the above mentioned species to the input power of the SDBD reactor. The simulation results are validated by a comparison with experimental data from absorption spectroscopy. The experimental measurements are carried out as follows. First, the discharge is turned on until the NO₂ number density reaches steady state. Then, the discharge is turned off for several minutes. Finally, the discharge is turned on again to observe the effects of the NO₂ concentration on ozone dynamics. The entire process is done without opening the box. The system operating in all the above-listed conditions is simulated for three different levels of input power.

A zero-dimensionl model is developed to study the chemical kinetics of a volumetric dielectric barrier discharge (DBD) reactor operating with humid air at atmospheric pressure. This work focuses on the relation between molecular vibrational excitation, the plasma reactor input power and the number densities of several species that are known to play an important role in biomedical applications (e.g. $$\textrm{O}_{3},\textrm{NO, NO}_{2}$$O 3 , NO, NO 2 , ...). A preliminary study is carried out to observe the influence of water molecules on the electron energy distribution function for different values of water concentration and reduced electric field. A simplified approach is then adopted to quantify the contribution of vibrationally-excited $$\textrm{O}_{2}$$O 2 molecules to $$\textrm{NO}$$NO formation. The results obtained using our detailed model suggest that for the physical conditions considered in this work $$\textrm{O}_{2}$$O 2 vibrational kinetics can be neglected without compromising the overall accuracy of the simulation. Finally, a reaction set is coupled with an equivalent circuit model to simulate the E-I characteristic of a typical DBD reactor. Different simulations were carried out considering different values of the average plasma input power densities. A particular focus was given to the influence of the Zeldovich mechanism on $$\textrm{O}_{3}$$O 3 and $$\textrm{NO}_\textrm{X}$$NO X production performing simulations where this reaction is not considered. The obtained results are shown and the role of vibrationally excited $$\textrm{N}_{2}$$N 2 molecules is discussed. The simulation results indicate also that $$\textrm{N}_{2}$$N 2 vibrational excitation, and more precisely the Zeldovich mechanism, has a larger effect on $$\textrm{O}_{3}$$O 3 and $$\textrm{NO}_\textrm{X}$$NO X production at intermediate input power levels.

We introduce a fluid computational model for the numerical simulation of atmospheric pressure dielectric barrier discharge plasmas. Ion and neutral species are treated with an explicit drift diffusion approach. The Boltzmann relation is used to compute the spatial distribution of electrons as a function of the electrostatic potential and the ionic charge density. This technique, widely used to speed up particle and fluid models for low-pressure conditions, poses several numerical challenges for high-pressure conditions and large electric field values typical of applications involving atmospheric-pressure plasmas. We develop a robust algorithm to solve the non-linear electrostatic Poisson problem arising from the Boltzmann electron approach under AC electric fields based on a charge-conserving iterative computation of the reference electric potential and electron density. We simulate a volumetric reactor in dry air, comparing the results yielded by the proposed method with those obtained when the drift diffusion approach is used for all charged species, including electrons. We show that the proposed methodology retains most of the physical information provided by the reference modeling approach while granting a substantial advantage in terms of computation time.

The functionality of buried metallic pipelines can be compromised by the electrical lines that share the same right-of-way. Given the considerable size of shared corridors, computer simulation is an important tool for performing risk assessment and mitigation design. In this work, we introduce an open-source computational framework for the analysis of electromagnetic interference on large earth-return structures. The developed framework is based on FLARE—an efficient finite element solver developed by the authors in MATLAB^®. FLARE includes solvers for problems involving static electric and magnetic fields, and DC and time-harmonic AC currents. Quasi-magnetostatic transient problems can be studied through time-marching or—for linear problems—with an efficient inverse-Laplace approach. In this work, we succinctly describe the optimization of time-critical operations in FLARE, as well as the implementation of a transient solver with automatic time-stepping. We validate the numerical results obtained with FLARE via a comparison with the commercial software COMSOL Multiphysics^®. We then use the validated time-marching analysis results to test the accuracy and efficiency of three numerical inverse-Laplace algorithms. The test problem considered is the assessment of the inductive coupling between a 500 $\mathrm{k}$$\mathrm{V}$ transmission line and a metallic pipeline buried in the soil.

A numerical methodology is proposed for the calculation of transient electromagnetic interference induced by overhead high-voltage power lines in metallic structures buried in soil—pipelines for oil or gas transportation. A series of 2D finite element simulations was employed to sample the harmonic response of a given geometry section. The numerical inverse Laplace transform of the results allowed obtaining the time domain evolution of the induced voltages and currents in the buried conductors, for any given condition of the power line.

This study presents a detailed investigation of a nanosecond-pulsed volume dielectric barrier discharge (VDBD) plasma in saturated humid air at atmospheric pressure, combining experimental diagnostics with kinetic modeling. Electric field-induced second harmonic generation (EFISH), employing a spatial filter and a picosecond laser, enabled electric field measurements with high spatial (270 µm) and temporal (28 ps) resolution at three distinct positions across the inter-electrode VDBD gap. These measurements revealed previously unobserved features and consistent differences between the discharge center and regions near the ground and high-voltage (HV) electrodes. Near the ground electrode, a higher electric field was observed prior to the first positive plasma discharge, along with an overshoot up to 50 kV cm⁻¹ during plasma breakdown, absent at the center and near the HV electrode. A sharper post-breakdown decrease and recovery in the electric field was also observed near the ground electrode, differently from the other positions. This pattern inverted during the subsequent negative discharge at the end of the HV pulse, with the higher electric field being measured near the HV electrode. To complement the electric field data, the concentrations of nitric oxide (NO) and hydroxyl radical (OH) were measured using laser-induced fluorescence (LIF), providing insight into their temporal dynamics during and after the discharge. The EFISH data served as input for a zero-dimensional kinetic model, which revealed the dynamics of both charged and neutral species, showing excellent agreement with the LIF data and validating the model accuracy. The simulation identified OH⁻, O 2 − , and O 4 − as the key negative ions responsible for the stable electric field after plasma breakdown. This research highlights the importance of understanding electric field dynamics and reactive species formation in low-temperature plasmas. Integrating EFISH and LIF data with kinetic modeling provides a robust framework to optimize plasma-based systems, improving their performance and safety in practical applications.