Advances and challenges in computational fluid dynamics of atmospheric pressure plasmas

Abstract

Atmospheric pressure plasmas (APPs) are at the core of diverse technological applications in materials processing, chemical synthesis, resource recovery, water treatment, and medicine, among others. APPs span a wide range of power density, from low-power non-thermal to highpower thermal discharges, and typically involve interactions with a stream of working gas, processing material, or gas environment. The article provides an overview of computational fluid dynamics (CFD) approaches, from mathematical models to software strategies, for the analysis of APP flows. Its focus is flows with large variations in ionization degree and significant fluid dynamic-thermal-electromagnetic coupling, as particularly found in mid-to high-power discharges. The advances achieved and challenges faced by CFD of APP flows have been driven by established and emerging applications, and can be broadly characterized in terms of model fidelity and numerical accuracy. Fidelity refers to the degree of underlying phenomena captured by the model, whereas accuracy to the precision of the numerical solution of the model. Two distinct numerical accuracy challenges are addressed: the capture of instability and pattern formation phenomena, and of plasma-gas interaction and turbulence; as well as two representative fidelity challenges: radiative transport under nonequilibrium conditions, and nonequilibrium electron and particle kinetics. The article aims to provide guidance to researchers, from modelers and code developers to open-source and commercial software users, working on CFD analyses of APP flows within technological contexts.

Microparticle cloud imaging and tracking for data-driven plasma science

“…Atmospheric pressure plasmas (APPs) are nonequilibrium plasmas produced at the ambient atmosphere. These plasmas are currently being investigated for a number of applications ranging from wound healing to material processing to water purification [61][62][63] . A particular class of these discharges is the 1 ATM DC glow with a liquid anode.…”

State of Art and Challenges for the Calculation of Radiative and Transport Properties of Thermal Plasmas in HVCB

“…As a consequence, the electron kinetic temperature T e is higher than the heavy particles temperature T h , and two-temperature models must be developed. The recent papers propose two equations of energy conservation: one for the electrons and the other for the heavy species [39]. These models require the computation of thermodynamic, transport and radiative properties as a function of T e and θ = T e /T h and the first step to obtain these data is, as in the case of LTE, the calculation of the 2T plasma composition.…”

Effect of Electromagnetic Boundary Conditions on Reliability of Plasma Torch Models

“…However, the level of predictability of the current models can be limited by the assumptions and boundary conditions. Recent reviews (Ref [1][2][3] pointed out two issues that often receive limited attention in the modeling of plasma spray torches:…”