Résumé
Through analysis of the experimental results of buoyancy-induced heat transfer deterioration at supercritical conditions, a theoretical model based on the force equilibrium is developed for the vertically upward supercritical flow under heating conditions. A program code is designed to simulate the effect of buoyancy on the degree of heat transfer deterioration. The simulation results for a wall temperature of 175? are presented. They show that the salient point in the M-shaped velocity profile plays a key role in heat transfer deterioration. The salient point locates at low y+ when the deterioration occurs, and it moves to higher y+ as the friction Reynolds number increases. Furthermore, the salient points will consistently locate behind the pseudocritical point in the boundary. Heat transfer will recover when the condition of force equilibrium is not met, manifested by bulk fluid temperature that is slightly lower than the pseudocritical temperature.
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Détails
- Titre original : Theoretical model for buoyancy-induced heat transfer deterioration under supercritical pressure.
- Identifiant de la fiche : 30024708
- Langues : Anglais
- Source : 2018 Purdue Conferences. 17th International Refrigeration and Air-Conditioning Conference at Purdue.
- Date d'édition : 09/07/2018
Liens
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Indexation
- Thèmes : Transfert de chaleur
- Mots-clés : État supercritique; Transfert de chaleur; Altération; Reynolds; Modélisation; Pression
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