The wall heat flux partitioning during the pool boiling of water on thin metallic foils

Zupančič, Matevž (author), Gregorčič, Peter (author), Bucci, Mattia (author), Wang, Chi (author), Aguiar, Gustavo Matana (author), Bucci, Matteo (author)

In this work, we studied the wall heat flux partitioning during the pool boiling of water on thin metallic surfaces. We conducted boiling experiments on surfaces where we engineered nucleation sites by nanosecond-fiber-laser texturing. These nucleation sites form triangular lattice patterns with different pitches. We measured the time-dependent temperature and heat flux distributions on the boiling surface using an infrared camera. We developed post-processing algorithms to measure, based on these distributions, all the fundamental boiling parameters used in heat flux partitioning models (e.g., nucleation site density, bubble wait and growth time, and bubble footprint radius) and the actual partitioning of the heat flux, i.e., how much heat is transferred by evaporation of the microlayer, rewetting of the surface, and convective effects. This work reveals that the mechanisms of heat transfer on substrates of small thermal capacity are very different compared to substrates of large thermal capacity. With water, the bubble microlayer typically does not dry out and the surface temperature at rewetting is practically the same as the rewetting fluid temperature. These effects limit the efficiency of microlayer evaporation and rewetting heat transfer. Instead, convective effects generated by the bubble growth process remove most of the energy from the heated surface. This behavior is captured by a heat flux partitioning model that we re-derived from first principles to describe the heat transfer mechanisms on substrate of small thermal capacity.

• Language: English
• Keywords: nucleate boiling, thin metallic foils, surface laser micro-engineering, infrared thermometry, heat flux partitioning
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FS - Faculty of Mechanical Engineering
• Publication status: Published
• Publication version: Version of Record
• Year: 2022
• Number of pages: 16 str.
• Numbering: Vol. 200, art. 117638
• PID: 20.500.12556/RUL-132089
• UDC: 536:66.02(045)
• ISSN on article: 1359-4311
• DOI: 10.1016/j.applthermaleng.2021.117638
• COBISS.SI-ID: 80131843
• Publication date in RUL: 12.10.2021

Record is a part of a journal

• Title: Applied thermal engineering
• Shortened title: Appl. therm. eng.
• Publisher: Elsevier
• ISSN: 1359-4311
• COBISS.SI-ID: 1861910

Licences

• License: CC BY-NC-ND 4.0, Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International
• Link: http://creativecommons.org/licenses/by-nc-nd/4.0/
• Description: The most restrictive Creative Commons license. This only allows people to download and share the work for no commercial gain and for no other purposes.

Secondary language

• Language: Slovenian
• Keywords: mehurčkasto vrenje, tanke kovinske folije, laserska mikroobdelava površin, infrardeča termografija, delitev toplotnega toka