Thermal atomization during droplet impingement on superhydrophobic surfaces: Influence of Weber number and micropost array configuration

An experimental study of thermal atomization intensity during droplet impingement on superheated hydrophobic and superhydrophobic surfaces varying microstructure was performed. Thermal in these scenarios is the result boiling, where vapor bubbles burst upwards through lamella, causing a fine spray secondary droplets. A smooth surface three post-patterned similar solid fraction but differing post size were investigated over range temperatures from 120 ∘C to 320 Weber numbers 20 200. Trends characterized using high-speed image processing technique. Changes temperature, number, configuration shown significantly influence intensity, parameters are thought be directly linked main mechanisms accounting for dynamics scenarios. These generation at liquid-solid interface impinging droplet, bursting spreading escape laterally beneath droplet. Vapor increases with an increase heat transfer which may produced by increasing temperature or contact wetting. lamella depends mainly thickness decreases number. Finally, occur as flows micropost arrays. This found enhanced spacing between structures. competing atomization, generally number decreasing pitch. Additionally, Leidenfrost point also scale analysis performed explore effect resistance arrays resulting scaling describes findings well.