Modeling of Thermal Plasma Processes: The Importance of Two‐Way Plasma‐Surface Interactions

Abstract

Most thermal plasma applications involve interactions between the plasma and solid or liquid surfaces. Computational models of thermal plasma applications typically consider the influence of the plasma on the surface, but often neglect the effect of the surface on the plasma. In many cases, however, it is not possible to accurately model the plasma process without taking the two‐way interactions into account. This is demonstrated using examples from arc welding, plasma cutting, plasm­a‐particle interactions, such as occur in plasma spheroidization, plasma nanoparticle production and plasma spraying, and high‐ and low‐voltage circuit breakers. Vaporization of metal, ceramic and polymer surfaces, transfer of heat and momentum from the plasma to particles and droplets, and changes in the surface shape are all shown to affect the properties of the plasma.

The future for plasma science and technology

“…For some specific applications, such as the cutting of thick steel pates by means of a hot plasma torch (plasma cutting), eg, thick steel plate cutting, there is to date no real alternative to the plasma‐based methods . Accordingly, considerable efforts are expanded on the improvement of all these technologies to meet changing demands . This includes in particular treatment of new materials for lightweight production, developments that are supporting increased automation, higher process stabilities, and efficiencies, as well as minimizing emissions.…”

“…Beside the bell‐shaped arc under the end of the wire, the weld pool (in red) and a droplet (white) can be well identified (G. Goett, Leibniz Institute for Plasma Science and Technology, Greifswald Germany, private communication). b) Iron vapor concentrations, temperature distribution and velocity vectors in a tungsten inert gas (argon) welding arc after 20 s of operation …”

Nonequilibrium Phenomena in (Quasi-)thermal Plasma Flows

“…Coupled plasma-electrode models are especially relevant to estimate heat transfer rates, and therefore expected electrode lifetime, in arc plasma torches, as demonstrated by the work of Alaya et al [3] and of Zhukovskii et al [103]. Moreover, coupled plasma-electrode models are essential for the description of arc welding processes [63,64]. This is distinctly exemplified by the recent work by Xiang et al [99] showing the transport of iron and chromium vapors from the weld pool to the cathode region in tungsten-inert-gas (TIG) welding using argon.…”

Development of a new OpenFOAM solver for plasma cutting modeling

“…Along with these experimental investigations, several modellings of the process have been presented since the end of the 1990's [1,4,5,[9][10][11][12][13][14][15][16][17]. The first CFD study of a plasma cutting configuration has been proposed by González-Aguilar et al [10].…”