Suppression of Leidenfrost Rebound and Enhanced Heat Transfer by Ionic Wind.

The Leidenfrost effect, in which a vapor film insulates a droplet from a superheated surface, severely limits heat transfer in spray cooling and quenching processes. Here, we investigate corona-discharge-induced ionic wind using a needle-array electrode system. By suppressing corona discharge, the effects of the electric field and ionic wind are distinguished. Under electric-field-only conditions, the maximum spreading factor increases from 2.007 to 2.124, but the residence time decreases from 15.4 to 13.8 ms. Ionic wind increases the maximum spreading factor to 2.395 and extends the residence time to 18.9 ms, with the strongest rebound suppression occurring near 7 kV. In the Leidenfrost regime, ionic wind reduces the droplet lifetime by up to 57.5%. Combined with a stainless-steel mesh, it cools the surface from 450 °C to below 300 °C within tens of seconds. These results demonstrate a tunable strategy for enhancing high-temperature phase-change cooling.