Prof. Fei DUAN

Nanyang Technological University, Singapore

Bio

Dr. Fei DUAN is a tenured faculty in School of Mechanical and Aerospace Engineering at Nanyang Technological University (NTU), Singapore. Dr. Duan obtained his Ph.D. degree in University of Toronto, Canada in 2005. Dr. Duan also worked as a visiting scientist in Institute of Fluid Mechanics at Friedrich-Alexander-University, Erlangen-Nuremberg, Germany. The topics of his research cover droplet wetting and evaporation dynamics, Marangoni flow energy transport, particle self-assembly, enhanced thermal management, efficient cogeneration system, etc. In NTU, Dr. Duan has secured over 12 million Singapore dollars on research funding from the governmental agencies and industries as a principal investigator. He has advised over 28 postdoctoral fellows or research associates, 18 Ph.D. students, and 14 Master’s students. Dr. Duan has published over 170 peer-reviewed journal papers, 4 patents, 5 book chapters, and 120 conference presentations including 18 plenary lectures and keynotes. He serves as Subject Editor for Applied Thermal Engineering (Elsevier, Impact Factor: 6.4), at Editorial Board for Scientific Reports (Nature Portfolio, Impact Factor: 4.8) and Frontiers in Heat and Mass Transfer (Tech Science Press); and Editor at Large in Droplet (Willy).

Title

Interfacial Energy and Mass Transfer During Droplet Evaporation

Abstract

Droplet phase changes between vapor and liquid phases are widely found in thermal management, advanced manufacturing, medical diagnosis, and energy applications. The fundamental mechanisms at interfaces, however, are beyond the sufficiently understanding. This talk starts from the interfacial temperature measurement at a steady-state experiments in evaporation of droplet to show the occurrence of thermocapillary convection driven by the surface tension gradient; The interfacial convection can transport up to 40% energy for phase change. Secondly, the hydrothermal waves are demonstrated in phase-change droplets, and explained the hydrothermal waves with the fluid flow patterns in the experiments of the particle image velocimetry and thermographic techniques. Thirdly, the deposition of sessile particle-laden droplets is shown on the flat and structured substrates. The transition of the particle aggregation is introduced from ring-shape, uniform and mixed patterns from the droplets with the circular and noncircular wetting. The diffusion-limited cluster-cluster aggregation model is developed to understand the depositions from coffee ring, uniform coverage, to disk-ring shape in the pinned sessile nanofluid droplet drying, while the kinetic Monte Carlo model is proposed to explain the branched particle self-assembly in drying the depinned droplets.