{"title":"Effect of the inclination angles of the capillary tube on the natural evaporation of absolute ethanol","authors":"","doi":"10.1016/j.expthermflusci.2024.111302","DOIUrl":null,"url":null,"abstract":"<div><p>Microchannel heat transfer plays an important role in microelectronics technology for heat dissipation, due to its high efficiency and low heat transfer temperature difference and flow resistance. To underpin the fundamental understanding of this technology, the natural evaporation process of absolute ethanol in a capillary tube at inclination angles ranging from 0° to 90° was investigated experimentally by exploring a spectrum of properties, such as Marangoni flow patterns, evaporation rate, heat flux, and temperature distribution. We found that the morphology of the meniscus is similar under different inclination angles, but the liquid and the tube wall slip to varying degrees due to the pressure difference at the liquid–vapor interface during evaporation. Therefore, the force distribution of the meniscus interface is different, and the resultant force is <em>F<sub>max</sub></em><sub>(60°)</sub> > <em>F<sub>max</sub></em><sub>(0°)</sub> > <em>F<sub>max</sub></em><sub>(30°)</sub> > <em>F<sub>max</sub></em><sub>(90°)</sub>. We found that the morphology of the meniscus is independent of the inclination angle when absolute ethanol evaporates naturally. And the evaporation rate, heat flux and temperature distribution of meniscus at the initial stage of evaporation follow the law of resultant force distribution. That is, when the inclination angle is 60°, the evaporation rate and heat flux reach the maximum, i.e. 1.64 μm/s and 10.96 W/cm<sup>2</sup>, respectively, and the temperature between the center of the meniscus and the wedge region reaches 1.5 ℃. We used μ-PIV to observe the Marangoni vortex morphology of the vertical section of the meniscus, and found that there are different degrees of deformation at different inclination angles. When the inclination angle is 90°, the Marangoni vortex structure is destroyed.</p></div>","PeriodicalId":12294,"journal":{"name":"Experimental Thermal and Fluid Science","volume":null,"pages":null},"PeriodicalIF":2.8000,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Experimental Thermal and Fluid Science","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0894177724001717","RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ENGINEERING, MECHANICAL","Score":null,"Total":0}
引用次数: 0
Abstract
Microchannel heat transfer plays an important role in microelectronics technology for heat dissipation, due to its high efficiency and low heat transfer temperature difference and flow resistance. To underpin the fundamental understanding of this technology, the natural evaporation process of absolute ethanol in a capillary tube at inclination angles ranging from 0° to 90° was investigated experimentally by exploring a spectrum of properties, such as Marangoni flow patterns, evaporation rate, heat flux, and temperature distribution. We found that the morphology of the meniscus is similar under different inclination angles, but the liquid and the tube wall slip to varying degrees due to the pressure difference at the liquid–vapor interface during evaporation. Therefore, the force distribution of the meniscus interface is different, and the resultant force is Fmax(60°) > Fmax(0°) > Fmax(30°) > Fmax(90°). We found that the morphology of the meniscus is independent of the inclination angle when absolute ethanol evaporates naturally. And the evaporation rate, heat flux and temperature distribution of meniscus at the initial stage of evaporation follow the law of resultant force distribution. That is, when the inclination angle is 60°, the evaporation rate and heat flux reach the maximum, i.e. 1.64 μm/s and 10.96 W/cm2, respectively, and the temperature between the center of the meniscus and the wedge region reaches 1.5 ℃. We used μ-PIV to observe the Marangoni vortex morphology of the vertical section of the meniscus, and found that there are different degrees of deformation at different inclination angles. When the inclination angle is 90°, the Marangoni vortex structure is destroyed.
期刊介绍:
Experimental Thermal and Fluid Science provides a forum for research emphasizing experimental work that enhances fundamental understanding of heat transfer, thermodynamics, and fluid mechanics. In addition to the principal areas of research, the journal covers research results in related fields, including combined heat and mass transfer, flows with phase transition, micro- and nano-scale systems, multiphase flow, combustion, radiative transfer, porous media, cryogenics, turbulence, and novel experimental techniques.