Corona Discharge in Wind: Revisited

Abstract:

Experimental and theoretical works of corona discharge in wind have dealt with grounded electrode systems. These works report a current increase with wind speed, first explained by S. Chapman (1970), as the effect of the wind is to remove the shielding ions from the coronating electrode vicinity, strengthening the corona. In the context of atmospheric electricity, corona discharges can be initiated by thunderstorm electric fields at the tips of pointed objects such as towers or trees. These coronae produce space charge layers that influence the spatial distribution of the electric fields and as a result can influence the initiation and progression of leaders. In the presence of wind the ion clouds are dispersed and their shielding effect is reduced, which qualitatively explains the observed preference of lightning attachment to rotating blades of windmills rather than to static towers (Montanya et al., 2014).

There are a number of problems that are not directly addressed by the literature: those that include electrically isolated electrode configurations. Examples are corona discharge appearing at sharp extremities in aircraft, helicopter and isolated wind turbine blade tips when exposed to thunderstorm fields. Of particular interest to the authors is using corona discharge to artificially charge an aircraft in flight (Pavan et al. 2020). This contribution reports wind tunnel experiments and simulation of the effect of wind on a positive glow corona discharge in air from a wire-wing electrode system, that is electrically isolated from its environment (Guerra-Garcia et al. 2020). We demonstrate that the classical scaling laws of corona discharge in wind do not apply for electrically isolated electrodes and that indeed corona can be used for charging.

Chapman, S. (1970). Journal of Geophysical Research, 75 (12), 2165-2169.

Montanya, J., van der Velde, O., and Williams, E. R. (2014). Journal of Geophysical Research: Atmospheres, 119, 1455-1462.

Pavan, C., Fontanes, P., Urbani, M., Nguyen, N. C., Martinez-Sanchez, M., Peraire, J., Montanya, J., and Guerra-Garcia, C. (2020). Journal of Geophysical Research: Atmospheres, 125, e2019JD031245.

Guerra-Garcia, C., Nguyen, N. C., Mouratidis, T., Martinez-Sanchez, M. (2020). Journal of Geophysical Research: Atmospheres, in press.