Temperature profiles in filamentary dielectric barrier discharges at atmospheric pressure

N Jidenko (1) , E Bourgeois (1) , J-P Borra (1)

1 LPGP - Laboratoire de physique des gaz et des plasmas

The physico-chemical properties of atmospheric pressure filamentary Dielectric Barrier Discharge (f-DBD) depend on its electrical characteristics and thermal profile. In this paper, a method for separating thermal and electrical effects is developed. Therefore, thermal profiles of f-DBD are studied for well defined electrical characteristics of filaments: all filaments are quasi identical with a controlled spatio-temporal density. The temperatures of gas, dielectric surface and plasma depend on the surface density and the temporal frequency of the filaments and can be altered by modifying the heat transfer. Different methods to control these temperatures are depicted. Moreover, heat transfer through conduction and convection from dielectric surface is shown to be the dominant heating mechanism for the flowing gas in the reactor. Finally, experimental results show that the temperature gradient around filaments can be controlled by the frequency of the applied voltage. Actually, the temperature difference between the filament and surrounding gas is independent of the applied frequency below 10 kHz. However, above 10 kHz, it increases linearly with the frequency. At high frequency, the time between two successive filaments occurring at the same position becomes smaller than the relaxation time constant of the thermal exchanges (~ 0.1 ms). Thus, this rise in temperature can be attributed to inefficient heat transfer from the filament formation zone.

Mots clés: Physical Sciences

Domaines: Physique [physics]

N Jidenko, E Bourgeois, J-P Borra. Temperature profiles in filamentary dielectric barrier discharges at atmospheric pressure. Journal of Physics D: Applied Physics, 2010, 43 (29), pp.295203. ⟨10.1088/0022-3727/43/29/295203⟩. ⟨hal-00569657⟩