SMuK 2021 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

P: Fachverband Plasmaphysik

P 3: Atmospheric Pressure Plasmas and their Applications I

P 3.3: Vortrag

Montag, 30. August 2021, 17:15–17:30, H6

Influence of the fluid flow description on the characteristics of a plasma spray torch — •Tao Zhu, Margarita Baeva, Thorben Kewitz, Holger Testrich, Detlef Loffhagen, and Rüdiger Foest — Leibniz Institute for Plasma Science and Technology, 17489 Greifswald, Germany

In direct current plasma spray torches operated at current values of several hundred Amperes, the velocity of the generated plasma jet can approach the speed of sound, i.e. Mach numbers (Ma) close to one are reached. Then, the description of the fluid flow can affect the models' predictions. We present a two-dimensional and stationary magneto-hydrodynamic model of a plasma in local thermodynamic equilibrium for the steady operating mode of a plasma spray torch. Approaches related to both low- and high-Ma (bounded by Ma=0.3) are considered on the computational platform COMSOL Multiphysics for a laminar and compressible flow with flow rates from 40 to 80 normal litre per minute (NLPM). The predicted pressure, plasma temperature, velocity, and electric potential differ depending on the approach employed. The thermal efficiency of the torch computed by the high-Ma model is between 50% and 60% and agrees well with experimental values. In contrast, a thermal efficiency of about 50% is predicted by the low-Ma model. It agrees with the measurements at a flow rate of 40 NLPM, but gradually decreases to about 40% for a flow rate of 80 NLPM.

This work is funded by the European Union and the Federal State of Germany Mecklenburg-Western Pomerania (Project number TBI-V-1-321-VBW-112).