Enhanced ionic wind output using emitter-surface decoration under varying ambient conditions

Ionic wind is a novel airflow phenomenon for cooling, food drying, and flow control etc. Decorating the emitter is an effective method to reduce corona-inception voltage and enhance wind-velocity output. However, its underlying correlation mechanisms have not been fully revealed, and the influence of ambient conditions on the effectiveness of emitter decoration remains unclear. In this study, an ionic wind blower is investigated to reveal the changes in corona-discharge behavior and ionic wind output after the emitter is decorated with graphene and carbon nanotubes (CNTs), respectively. The influence of temperature and humidity on the effectiveness of emitter decoration in enhancing corona and ionic wind output are clearly identified. The results indicate graphene decoration increases the Trichel-pulse frequency (by at least 16.83 % at 20 °C) but reduces pulse amplitudes, while CNT decoration has the opposite effect, reducing the frequency by up to 52.4 % at 20 °C. Emitter decoration lowers the corona-inception voltage and increases discharge current at low humidity. High humidity weakens or even cancels the effectiveness of emitter decoration in enhancing corona. Temperature rise further suppresses the intended enhancement effect of emitter decoration owing to the increased current magnitude and intensified condensation. Emitter decoration significantly boosts ionic wind velocity and remains effective across varying temperatures and humidity levels. CNT decoration is more effective than graphene decoration, proving the advantages of micron-scale discharge sites.