77th Annual Meeting of the APS Division of Fluid Dynamics (November 24, 2024 — November 26, 2024)

V2684780: Damped bouncing of Leidenfrost drops

Authors

• Gopal Pal, Indian Institute of Technology Ropar
• Pawan Indolia, Indian Institute of Technology Ropar
• NARENDRA BAHADUR, Indian Institute of Technology Ropar
• Devranjan Samanta, Department of Mechanical Engineering, Indian Institute of Technology Ropar, Punjab–140001, India
• Chander S. Sharma, Thermofluidics Research Laboratory, Department of Mechanical Engineering, Indian Institute of Technology Ropar, Rupnagar, Punjab 140 001, India

DOI: https://doi.org/10.1103/APS.DFD.2024.GFM.V2684780

A drop on a sufficiently hot surface floats over a cushion of its own vapor. This phenomenon, commonly referred to as the Leidenfrost effect, is observed across multiple applications. Leidenfrost droplets below capillary length spontaneously bounce on the hot surface. Such bouncing is caused by overpressure in the vapor cushion arising from pressure perturbations due to capillary ripples. In this video, we show that such droplet bouncing is damped on textures with interconnected cavities. The textures have spatial wavelength comparable to that of ripples at the droplet base that disrupt the overpressure responsible for droplet bouncing. If the cavities are isolated, then the bouncing is damped only partially. The reduced bouncing improves the overall droplet evaporation rate