TY - JOUR

T1 - DYNAMICS OF BUBBLES AND DRY SPOTS UNDER THE HEATED DOWNWARD-FACING SUBSTRATE

AU - Mungalov, Aleksandr S.

AU - Derevyannikov, Ivan A.

AU - Kochkin, Dmitry Yu

AU - Kabov, Oleg A.

AU - Marchuk, Igor V.

AU - Luo, Zhengyuan

AU - Sun, Chengzhen

AU - Bai, Bofeng

N1 - Финансирующий спонсор Номер финансирования Акроним Russian Foundation for Basic Research RFBR National Natural Science Foundation of China 21-58-53050 NSFC Dynamics of bubbles and dry spots under the heated downward-facing substrate / A. Mungalov, I. Derevyannikov, D. Kochkin [et al.] // Interfacial Phenomena and Heat Transfer. – 2024. – DOI 10.1615/interfacphenomheattransfer.2024054467.

PY - 2025

Y1 - 2025

N2 - A comprehensive methodological approach is used to study bubble dynamics under the downward-facing substrate including high-speed imaging and interferometry simultaneously with shadow technique and infrared thermometry. A transparent indium-tin-oxide heater deposited on a sapphire substrate is utilized. This approach allows bubble and dry-spot dynamics, bubble coalescence, and the formation and evaporation of the microlayer to be investigated. The fluorocarbon liquid FC-72 is used as the working fluid. The study revealed significant nonlinear bubble and dry-spot growth rates with increasing heating power. The motion of the bubble relative to the heated substrate facilitates the formation of a microlayer at the bubble’s periphery. It was observed that bubbles moving at higher velocity along the substrate at the same heating power experienced faster growth, apparently due to an increase in the area of the microlayer. It is established that the coalescence of bubbles results in the formation of a microlayer under the resulting bubble. The dynamics of the microlayer after coalescence is studied using interferometry. A significant increase in the evaporation rate of the microlayer with increasing heating power is observed. The considered processes play an important role in the microgravity conditions where, due to the lack of buoyancy force, the bubble does not detach from the heater. The presented experimental results can be useful for a deep understanding of bubble dynamics under the heated downward-facing substrate and for the future model development.

AB - A comprehensive methodological approach is used to study bubble dynamics under the downward-facing substrate including high-speed imaging and interferometry simultaneously with shadow technique and infrared thermometry. A transparent indium-tin-oxide heater deposited on a sapphire substrate is utilized. This approach allows bubble and dry-spot dynamics, bubble coalescence, and the formation and evaporation of the microlayer to be investigated. The fluorocarbon liquid FC-72 is used as the working fluid. The study revealed significant nonlinear bubble and dry-spot growth rates with increasing heating power. The motion of the bubble relative to the heated substrate facilitates the formation of a microlayer at the bubble’s periphery. It was observed that bubbles moving at higher velocity along the substrate at the same heating power experienced faster growth, apparently due to an increase in the area of the microlayer. It is established that the coalescence of bubbles results in the formation of a microlayer under the resulting bubble. The dynamics of the microlayer after coalescence is studied using interferometry. A significant increase in the evaporation rate of the microlayer with increasing heating power is observed. The considered processes play an important role in the microgravity conditions where, due to the lack of buoyancy force, the bubble does not detach from the heater. The presented experimental results can be useful for a deep understanding of bubble dynamics under the heated downward-facing substrate and for the future model development.

KW - ITO heater

KW - bubble

KW - coalescence

KW - downward-facing substrate

KW - dry spots

KW - microlayer

UR - https://www.mendeley.com/catalogue/44d52883-9d39-317a-8abf-c20a821e5937/

UR - https://www.scopus.com/record/display.uri?eid=2-s2.0-86000334801&origin=inward&txGid=fd6561aede57fcc2b4af572cf6117292

UR - https://www.elibrary.ru/item.asp?id=78905373

U2 - 10.1615/InterfacPhenomHeatTransfer.2024054467

DO - 10.1615/InterfacPhenomHeatTransfer.2024054467

M3 - Article

VL - 13

SP - 25

EP - 43

JO - Interfacial Phenomena and Heat Transfer

JF - Interfacial Phenomena and Heat Transfer

SN - 2169-2785

IS - 1

ER -