NUMERICAL SIMULATION OF ATMOSPHERIC PRESSURE TOWNSEND DISCHARGES IN NITROGEN WITH HYDROGEN GAS ADMIXTURES
| Authors | |
|---|---|
| Year of publication | 2008 |
| Type | Article in Proceedings |
| Conference | Proccedings of HAKONE X |
| MU Faculty or unit | |
| Citation | |
| Field | Plasma physics |
| Keywords | electrical discharge; atmospheric pressure; nitrogen |
| Description | In this contribution the influence of hydrogen admixture on an Atmospheric Pressure Townsend Discharge (APTD) in nitrogen is investigated by means of numerical modelling and experiments. The numerical model is a one-dimensional fluid model. Electron emission from dielectrics by a diffusion flux of metastable molecules and photoemission are incorporated in the model. The secondary emission due to ions is neglected. The results are compared with measured electrical parameters (ignition voltage, voltage necessary for causing the transition to the filamentary regime and current evolution). The measured and simulated current profiles of discharge in nitrogen-hydrogen mixture are similar for applied voltages close to ignition voltage. The simulations give a qualitative explanation for the measured current profiles in pure nitrogen and for small admixtures of hydrogen. The results indicate that the influence of hydrogen on the APTD is due to the quenching of the main metastable state N2(A 3 Sigma+ u ) by hydrogen molecules and atoms. Generally a APTD typical one peak current structure is caused by secondary electron emission by nitrogen metastable molecules, a current pulse with multiple peaks is caused mainly by secondary emission of ions or photoemission. |
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