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Etude expérimentale des profils du taux de vide lors de l'ébullition libre sur une surface verticale.

Experimental study of void fraction profiles in pool boiling on a vertical surface.

Auteurs : LOUAHLIA-GUALOUS H., LALLEMAND M.

Type d'article : Article

Résumé

An experimental study of saturated nucleate pool boiling of n-pentane on a vertical surface was conducted. The boiling surface was 120 mm high and 60 mm wide. Using a hot wire anemometer, void fraction profiles were measured along the height, width, and the normal of the heated surface for different heat fluxes. The output signals of the hot wire anemometer were treated in order to characterize the boiling flow. The contribution of long, average, and short bubbles along the width and the height of the heated surface are identified for various heat flux. Three different boiling regimes were defined and the transition heat flux density was determined and compared to the results of Gaertner. The wavelength of vapour waves formed on the heater was measured and was found to be higher than the critical wavelength characteristic of the Taylor instability. The experimental results showed that the wavelength is independent of the heat flux and increased along the heater height. However, the number of the wetting zones decreased because of the waves merging and stretching. The physical mechanisms that trigger critical heat flux were identified.

Détails

  • Titre original : Experimental study of void fraction profiles in pool boiling on a vertical surface.
  • Identifiant de la fiche : 2004-2183
  • Langues : Anglais
  • Source : Applied Thermal Engineering - vol. 23 - n. 18
  • Date d'édition : 12/2003

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