Visualisation des structures en ébullition lors de l'ébullition libre à flux thermique élevé.

Visualization of boiling structures in high heat-flux pool-boiling.

Auteurs : NISHIO S., TANAKA H.

Type d'article : Article

Résumé

This article presents experimental results of observation of liquid-solid contact and bubble behaviours around the critical heat flux of saturated and subcooled pool boiling on a plate of single crystal sapphire. The observation was conducted from the back of a rectangular boiling surface and also from the side and back of a boiling surface with a narrow width. The main results obtained are summarized as follows. The bubble base area was almost dry and lateral coalescence of bubbles forms coalescent dry areas. As the wall superheat increases, liquid-solid contact becomes like a canal meandering through dry areas. The dependency on the surface superheat of the contact-line length density (CLLD) which is defined as the total length of the boundary between wetted and dry areas in a unit area was almost the same as the boiling curve, and the value of CLLD at CHF was not strongly dependent on boiling liquid and subcooling. The relation of the number and density of dry areas and their equivalent diameter in the large dry area region at CHF was not dependent on boiling liquid and subcooling, and it was similar to that of drop-wise condensation.

Détails

  • Titre original : Visualization of boiling structures in high heat-flux pool-boiling.
  • Identifiant de la fiche : 2005-0613
  • Langues : Anglais
  • Source : International Journal of Heat and Mass Transfer - vol. 47 - n. 21
  • Date d'édition : 10/2004

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