EFFECTS STUDY OF SOLID PROTUBERANCES PROPERTIES ON THE TURBULENT NATURAL CONVECTION PERFORMANCE INSIDE A VERTICAL CHANNEL
Résumé
Dans cette étude, nous présentons des prédictions numériques des effets des propriétés géométriques, physiques et thermiques des protubérances, telles que la conductivité thermique des protubérances solides, les rapports d’aspect et les intensités du flux de chaleur exercées sur les faces externes des protubérances, sur la convection naturelle turbulente dans un canal vertical. Les résultats de l’analyse du transfert de chaleur sont obtenus en solutionnant les équations de l’écoulement de chaleur et des fluides en utilisant le modèle de la turbulence. Le système étudié est bidimensionnel, turbulent et permanant. La procédure numérique étend sur un code numérique qui modélise l’écoulement de chaleur et des fluides. Les résultats sont données en termes des champs et des profils des propriétés locales telles que la température, la vitesse, le coefficient de transfert de chaleur et l’intensité de la turbulence pour différents valeurs du rapport d’aspect des protubérances, la conductivité thermique et le flux de chaleur exercé sur les faces externes des protubérances. Les champs des propriétés d’air physiques et thermiques montrent des comportements différents en fonction de la valeur du rapport d’aspect des protubérances. Un effet positif sur le rendement de la convection naturelle turbulente a été prédit, dans la plage de 0 à 6,5%, par rapport à un canal vertical sans protubérances '. La présence des protubérances c’est un facteur important dans l’amélioration du rendement de la convection naturelle turbulente dans un canal vertical.
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