Importance of near surface effects during bubble life cycle for enhanced nucleate boiling heat transfer
Séminaire Matevz Zupancic – Université de Ljubljana (Slovénie)
Mardi 31 octobre à 10 h 00 – Amphithéâtre Nougaro
Near surface effects in nucleate pool boiling can be considered on a scale of several micrometers (effects related to microlayer and contact line evaporation), tens of micrometers (i.e., the extent of the thermal boundary layer), of several hundreds of micrometers (micro convective flows due to bubble dynamics and coalescence events) being effective up to the phenomenological characteristic length (i.e., the bubble departure diameter). Interplay between different phenomena is still not fully understood, also because in-liquid transient temperature field around the growing/departing bubbles cannot be easily experimentally determined. The presentation will outline our current understanding about near surface effects related to enhanced nucleate boiling heat transfer, developed and emerging experimental techniques that would help in further studies, and new experimental results obtained on laser-textured surfaces through synchronized high-speed imaging, IR thermography and in-liquid temperature measurement through microthermocouple.
