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Production of long, laminar plasma jets at atmospheric pressure with multiple cathodes
Author(s) -
Wang Cheng,
Cui Haichao,
Zhang Zelong,
Xia Weiluo,
Xia Weidong
Publication year - 2017
Publication title -
contributions to plasma physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.531
H-Index - 47
eISSN - 1521-3986
pISSN - 0863-1042
DOI - 10.1002/ctpp.201600073
Subject(s) - laminar flow , nozzle , plasma , jet (fluid) , plasma torch , atmospheric pressure plasma , materials science , anode , atmospheric pressure , cathode , plasma arc welding , turbulence , atomic physics , helium , arc (geometry) , mechanics , physics , thermodynamics , chemistry , electrode , meteorology , nuclear physics , geometry , mathematics , quantum mechanics
Plasma jets from conventional non‐transferred arc plasma devices are usually operated in turbulent flows at atmospheric pressure. In this paper, a novel non‐transferred arc plasma device with multiple cathodes is introduced to produce long, laminar plasma jets at atmospheric pressure. A pure helium atmosphere is used to produce a laminar plasma jet with a maximum length of >60 cm. The influence of gas components, arc currents, anode nozzle diameter, and gas flow rate on the jet characteristics is experimentally studied. The results reveal that the length of the plasma jet increases with increasing helium content and arc current but decreases with increasing nozzle diameter. As the gas flow rate increases, the length of the plasma jet initially increases and then decreases. Accordingly, the plasma jet is transformed from a laminar state to a transitional state and finally to a turbulent state. Furthermore, the anode arc root behaviours corresponding to different plasma jet flows are studied. In conclusion, the multiple stationary arc roots that exist on the anode just inside the nozzle entrance are favourable for the generation of a laminar plasma jet in this device.