Experimental investigation of micro-scale heat transfer at an evaporating moving 3-phase contact line
2010 14th International Heat Transfer Conference • 2010
Publication Information
Authors
K Ibrahem, MF Abd Rabbo, T Gambaryan-Roisman, P Stephan
Keywords
3-phase contact line; heat transfer; evaporation; micro region
Journal
2010 14th International Heat Transfer Conference
Publisher
American Society of Mechanical Engineers
Volume
3
Issue
August 8–13, 2010
Pages
783-790
publication.type
International
Paper Link
Open Link
Supplementary Materials
Not Available
Abstract
An experimental study is conducted to investigate the microscale
heat transfer at an evaporating moving 3-phase contact line. The moving evaporating meniscus is formed by pushing or sucking a liquid column of HFE7100 in a vertical channel of 600 μm width using a syringe pump. The gas atmosphere is pure HFE7100 vapor. This channel is built using two parallel flat plates. A 10 μm thick stainless steel heating foil forms a part of one of the flat plates. Two dimensional microscale temperature field at the back side of the heating foil is observed with a high speed infrared camera with a spatial resolution of 14.8 μm × 14.8 μm and an insitu calibration procedure is used at each pixel element. A high speed CMOS camera is
used to capture the shape of the moving meniscus, the images are post processed to track the free surface of the meniscus. Local heat fluxes from the heater to the evaporating meniscus are calculated from the measured transient wall temperature distributions using an energy balance for each pixel element. In the vicinity of the 3-phase contact line the heat flux distribution shows a local maximum due to high evaporation rates at this small region. The local maximum heat flux at the 3-phase contact line
area is found to be dependent on the input heat flux, the velocity and the direction of the meniscus movement. The results give detailed insight into the specific dynamic microscale heat and fluid transport process.
heat transfer at an evaporating moving 3-phase contact line. The moving evaporating meniscus is formed by pushing or sucking a liquid column of HFE7100 in a vertical channel of 600 μm width using a syringe pump. The gas atmosphere is pure HFE7100 vapor. This channel is built using two parallel flat plates. A 10 μm thick stainless steel heating foil forms a part of one of the flat plates. Two dimensional microscale temperature field at the back side of the heating foil is observed with a high speed infrared camera with a spatial resolution of 14.8 μm × 14.8 μm and an insitu calibration procedure is used at each pixel element. A high speed CMOS camera is
used to capture the shape of the moving meniscus, the images are post processed to track the free surface of the meniscus. Local heat fluxes from the heater to the evaporating meniscus are calculated from the measured transient wall temperature distributions using an energy balance for each pixel element. In the vicinity of the 3-phase contact line the heat flux distribution shows a local maximum due to high evaporation rates at this small region. The local maximum heat flux at the 3-phase contact line
area is found to be dependent on the input heat flux, the velocity and the direction of the meniscus movement. The results give detailed insight into the specific dynamic microscale heat and fluid transport process.
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