Arrêt de service lundi 11 juillet de 12h30 à 13h : tous les sites du CCSD (HAL, EpiSciences, SciencesConf, AureHAL) seront inaccessibles (branchement réseau à modifier)
Accéder directement au contenu Accéder directement à la navigation
Article dans une revue

Analytical interpretation of arc instabilities in a DC plasma spray torch: the role of pressure

Vincent Rat 1 Jean-François Coudert 1 
1 SPCTS-AXE2 - Axe 2 : procédés plasmas et lasers
SPCTS - Science des Procédés Céramiques et de Traitements de Surface
Abstract : Arc instabilities in a plasma spray torch are investigated experimentally and theoretically thanks to a linear simplified analytical model. The different parameters that determine the useful properties of the plasma jet at the torch exit, such as specific enthalpy and speed, but also pressure inside the torch and time variations of the flow rate are studied. The work is particularly focused on the link between the recorded arc voltage and the pressure in the cathode cavity. A frequency analysis of the recorded voltage and pressure allows the separation of different contributions following their spectral characteristics and highlights a resonance effect due to Helmholtz oscillations; these oscillations are responsible for the large amplitude fluctuations of all the parameters investigated. The influence of heat transfer, friction forces and residence time of the plasma in the nozzle are taken into account, thanks to different characteristics' times. The volume of the cathode cavity in which the cold gas is stored before entering the arc region appears to be of prime importance for the dynamics of instabilities, particularly for the non-intuitive effect that induces flow-rate fluctuations in spite of the fact that the torch is fed at a constant flow rate.
Liste complète des métadonnées
Contributeur : BEATRICE DERORY Connectez-vous pour contacter le contributeur
Soumis le : lundi 17 septembre 2018 - 11:38:56
Dernière modification le : samedi 26 mars 2022 - 04:28:00




Vincent Rat, Jean-François Coudert. Analytical interpretation of arc instabilities in a DC plasma spray torch: the role of pressure. Journal of Physics D: Applied Physics, IOP Publishing, 2016, 49 (23), pp.235202. ⟨10.1088/0022-3727/49/23/235202⟩. ⟨hal-01875355⟩



Consultations de la notice