Droplet evaporation on bio-inspired surfaces considering the electric field based on MRT-LBM

Droplet collisions on superheated solid surfaces under the electric field are universal phenomenon in both nature and industrial production processes. The electric field intensity and textured surface morphology are crucial factors influencing droplet evaporation. However, the understanding of how droplets impact and evaporate on textured surfaces with the electric field is limited. The research investigates how droplets morphologically change upon impacting superheated bio-inspired surfaces under the electric field, based on the multiphase and thermal multiple-relaxation-time lattice Boltzmann method that incorporates the leaky dielectric model. The bio-inspired surfaces, characterized by reentrant pillars, are designed based on the cuticles of springtails. Factors such as electric capillary number, Weber number, and microstructural morphology are taken into account for the effects of droplet collision and evaporation. The results indicate that an enhanced electric field promotes droplet evaporation during film evaporation. Nevertheless, in the context of nucleate boiling, the enhanced electric field does not consistently facilitate droplet evaporation. When the ratio of substrate temperature to critical temperature $\left(T_h/T_c\right)$ is 0.90 and the Weber number is 85.5, the droplet breaks through the energy barriers of the structure, even without the electric field. Droplet lifetime on the superheated bio-inspired surface is shortest when $T_h/T_c=0.90,1.02,1.06$ with the electric field, measuring 76.27 %, 46.36 %, and 56.78 % of that on the micro-pillar surface, respectively. This study provides valuable insights into accurately controlling electric fields to enhance the evaporation of droplets.