Droplet evaporation on a structured surface: The role of near wall vortexes in heat and mass transfer
| Parent link: | International Journal of Heat and Mass Transfer Vol. 148.— 2019.— [119126, 23 p. |
|---|---|
| Enti autori: | , |
| Altri autori: | , , , |
| Riassunto: | Title screen Experimental studies on the evaporation of a drop located on a horizontal hot wall with cavities of different diameters of 0.5-2.5 mm were carried out. The wall temperature Tw was constant (74 °C and 83 °C). The evaporation behavior on a structured surface was compared with that on a smooth wall. Instantaneous velocity profiles have been obtained over a single cavity and in the vicinity of several cavities using the Micro Particle Image Velocity method (Micro PIV). It has been established that a hotter liquid is periodically ejected from the cavity, which increases convection inside the drop. The strongest intensification of mass transfer is specific for the largest cavities with a diameter of 2.5 mm. The behavior of the droplet evaporation on a smooth wall coincides with that on a structured surface with a cavity diameter of 0.5 mm. Until now, there have been no data that would link the convection in the drop with the vortexes in the cavity at non-isothermal evaporation and at high heat fluxes. The strongest influence of cavities is manifested in the initial period of evaporation, when a cold drop is placed on a hot wall. Over time, the evaporation rate on a structured wall approaches evaporation on a smooth (unstructured) surface. The article considers the influence of several key factors on the convection in a drop. Режим доступа: по договору с организацией-держателем ресурса |
| Lingua: | inglese |
| Pubblicazione: |
2019
|
| Soggetti: | |
| Accesso online: | https://doi.org/10.1016/j.ijheatmasstransfer.2019.119126 |
| Natura: | Elettronico Capitolo di libro |
| KOHA link: | https://koha.lib.tpu.ru/cgi-bin/koha/opac-detail.pl?biblionumber=661372 |
| Riassunto: | Title screen Experimental studies on the evaporation of a drop located on a horizontal hot wall with cavities of different diameters of 0.5-2.5 mm were carried out. The wall temperature Tw was constant (74 °C and 83 °C). The evaporation behavior on a structured surface was compared with that on a smooth wall. Instantaneous velocity profiles have been obtained over a single cavity and in the vicinity of several cavities using the Micro Particle Image Velocity method (Micro PIV). It has been established that a hotter liquid is periodically ejected from the cavity, which increases convection inside the drop. The strongest intensification of mass transfer is specific for the largest cavities with a diameter of 2.5 mm. The behavior of the droplet evaporation on a smooth wall coincides with that on a structured surface with a cavity diameter of 0.5 mm. Until now, there have been no data that would link the convection in the drop with the vortexes in the cavity at non-isothermal evaporation and at high heat fluxes. The strongest influence of cavities is manifested in the initial period of evaporation, when a cold drop is placed on a hot wall. Over time, the evaporation rate on a structured wall approaches evaporation on a smooth (unstructured) surface. The article considers the influence of several key factors on the convection in a drop. Режим доступа: по договору с организацией-держателем ресурса |
|---|---|
| DOI: | 10.1016/j.ijheatmasstransfer.2019.119126 |