TIR4CPC: Total Internal Reflection for Condensation Phase-Change
Abstract
The interactions between liquids and solid surfaces are ubiquitous in nature and in everyday industrial and domestic applications. Liquids in the form of films or droplets wet and/or spread upon contact with a solid surface and then evaporate and/or condense if the liquid is not in equilibrium with its vapor. Evaporation and condensation phase-change encompass both heat and mass transfer, both mechanisms being relevant to thermal management, microfluidics, transportation sector, medical and biomedical applications, among others. More specifically, dropwise condensation and flow condensation phase-change of water and refrigerants has played an important role in several thermal management applications as per their greater heat fluxes and heat transfer performance when compared to single phase. Nonetheless, controlling and ensuring maximum heat fluxes during condensation phase-change are still a challenge as per our impossibility to date to access the direct relevant interactions taking place between the condensing fluids and the condenser orsolid surface during condensation phase-change. Common methodologies addressing the solid-liquid interactions during condensation rely on a top-bottom or side-view approach; where the fundamental liquid-solid and triple-phase contact line (TPCL) interactions remain hidden by the shape of the droplets and the experimental technique adopted. This is further intensified on superhydrophilic or superhydrophobic surfaces. To overcome such challenge, Total Internal Reflection (TIR) is applied to condensation phase-change for thefirst time. In order to achieve so, TIR needs to be carefully coupled to an environmental chamber so to control the environment between the imaging path, as well as to high-speed optical microscopy so to empower unprecedented spatial resolutions. The use of long working distance optical microscopy and/or high magnification lenses will contribute to achieve the spatial resolutions down to a µm/px, i.e., 2 to 3 orders of magnitude smaller than current TIR of 20 µm/px, with the consequent better elucidation of the different static and dynamic interactions taking place during condensation and flow condensation.The accurate elucidation and understanding ofthe direct interactions between liquid films and/or droplets and solid surfaces at the solid-liquid interface is of outermost importance for precise design and implementation of applications were droplet manipulation and control is desired. Hence, findings unveiled anticipate the development of our fundamental understanding on the effect of wettability and solid structures during condensationand flow-boiling condensation enabling high heat fluxes. Such findings align with the Office of Naval Research as well as with the UN Sustainability Development Goal 6: Clean Water & Sanitation & 7: Affordable & Clean Energy.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Nov 08, 2024
- Source ID
- N000142412450
Entities
People
- Daniel Orejon
Organizations
- Office of Naval Research
- United States Navy
- University of Edinburgh