Condensation, evaporation and boiling of falling films in wickless heat pipes (two-phase closed thermosyphons): A critical review of correlations
| Autor: | Guichet, Valentin, Jouhara, Hussam |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
Falling film
Materials science 020209 energy Thermal resistance lcsh:Heat Evaporation 02 engineering and technology Heat transfer coefficient 020401 chemical engineering Boiling Heat transfer 0202 electrical engineering electronic engineering information engineering 0204 chemical engineering Fluid Flow and Transfer Processes Mechanical Engineering Condensation Mechanics lcsh:QC251-338.5 Condensed Matter Physics Nusselt number Thermosyphon Correlation Heat pipe Thermosiphon |
| Zdroj: | International Journal of Thermofluids, Vol 1, Iss, Pp 100001-(2020) International Journal of Thermofluids |
| ISSN: | 2666-2027 |
| Popis: | With the objective of estimating the thermal resistance of a two-phase closed thermosyphon (TPCT), the work presented is a state of the art of condensation and falling film evaporation/boiling correlations. A deep analysis of up-to-date reported equations dealing with falling film heat transfer is carried out and recommendations are provided to select the most suitable and reliable correlations. Mechanisms such as filmwise condensation and Nusselt theory, falling film development in the thermal entry length (TEL), film thickness, appearance of waves and turbulence, two-phase flow interaction and entrainment with the shear stress at the liquid-vapour interface, falling film evaporation and boiling, in addition to film breakdown, are comprehensively explained and discussed. For all sections, the advised correlations are reported in a clear and simple way using tables. The objective of this paper is to cover sufficient knowledge on the falling film dynamic in thermosyphons to ease the prediction of heat transfer coefficients. This paper can be taken as a starting point for thermosyphon users in the study of falling film heat transfer in wickless heat pipes. |
| Databáze: | OpenAIRE |
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