Abstract
The introduction of a small volume of liquid into a turbulent gas stream used as cooling agent improves considerably the heat transfer coefficient of the gas. When the turbulent regime is established, one observes in a cylindrical tube two types of flow whether the liquid wets or does not wet the wall. In the first case, one gets on the wall an annular liquid film and droplets in suspension are in the gas stream. In the second case, a fog of droplets is formed without any liquid film on the wall. Experiments were performed with the following mixtures: water-hydrogen, water-nitrogen, ethanol-nitrogen (wetting liquids) introduced into a stainless steel tube of 4 mm ID, electrically heated on 320 mm of length. We varied the gas flow rate (Reynolds until 50000), the rate of the liquid flow rate to gas flow rate (until 15), the pressure (until 10 kg/cm{sup 2}), the temperature (until the boiling point) and the heat flux (until 250 W/cm{sup 2}). Two types of burnout were observed. A formula of correlation of the burnout heat flux is given. Making use of the analogy between mass transfer and heat transfer, a dimensionless formula of correlation of the local heat transfer
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Grison, E;
[1]
Commissariat a l'Energie Atomique, Saclay (France).Centre d'Etudes Nucleaires]
- Commissariat a l'Energie Atomique, Lab. de Physique-Chimie et basses temperatures, Grenoble (France).Centre d'Etudes Nucleaires
Citation Formats
Grison, E, and Commissariat a l'Energie Atomique, Saclay (France).Centre d'Etudes Nucleaires].
Heat transfer by liquids in suspension in a turbulent gas stream (1960); Transfert de chaleur par liquides entraines dans un ecoulement gazeux turbulent (1960).
France: N. p.,
1960.
Web.
Grison, E, & Commissariat a l'Energie Atomique, Saclay (France).Centre d'Etudes Nucleaires].
Heat transfer by liquids in suspension in a turbulent gas stream (1960); Transfert de chaleur par liquides entraines dans un ecoulement gazeux turbulent (1960).
France.
Grison, E, and Commissariat a l'Energie Atomique, Saclay (France).Centre d'Etudes Nucleaires].
1960.
"Heat transfer by liquids in suspension in a turbulent gas stream (1960); Transfert de chaleur par liquides entraines dans un ecoulement gazeux turbulent (1960)."
France.
@misc{etde_20943001,
title = {Heat transfer by liquids in suspension in a turbulent gas stream (1960); Transfert de chaleur par liquides entraines dans un ecoulement gazeux turbulent (1960)}
author = {Grison, E, and Commissariat a l'Energie Atomique, Saclay (France).Centre d'Etudes Nucleaires]}
abstractNote = {The introduction of a small volume of liquid into a turbulent gas stream used as cooling agent improves considerably the heat transfer coefficient of the gas. When the turbulent regime is established, one observes in a cylindrical tube two types of flow whether the liquid wets or does not wet the wall. In the first case, one gets on the wall an annular liquid film and droplets in suspension are in the gas stream. In the second case, a fog of droplets is formed without any liquid film on the wall. Experiments were performed with the following mixtures: water-hydrogen, water-nitrogen, ethanol-nitrogen (wetting liquids) introduced into a stainless steel tube of 4 mm ID, electrically heated on 320 mm of length. We varied the gas flow rate (Reynolds until 50000), the rate of the liquid flow rate to gas flow rate (until 15), the pressure (until 10 kg/cm{sup 2}), the temperature (until the boiling point) and the heat flux (until 250 W/cm{sup 2}). Two types of burnout were observed. A formula of correlation of the burnout heat flux is given. Making use of the analogy between mass transfer and heat transfer, a dimensionless formula of correlation of the local heat transfer coefficients is established. (author) [French] L'introduction d'un faible volume de liquide dans un ecoulement gazeux turbulent utilise comme fluide refrigerant permet une amelioration considerable des coefficients d'echanges thermiques que l'on aurait si le gaz etait employe seul (nous avons obtenu un facteur d'amelioration superieur a 10). En regime turbulent etabli, on observe dans un tube deux modes d'ecoulements selon que le liquide mouille ou ne mouille pas la paroi. Dans le premier cas, on obtient sur la paroi un film annulaire liquide et des gouttelettes en suspension dans le coeur gazeux. Dans le deuxieme cas, il se forme un veritable brouillard sans film liquide sur la paroi. Les etudes experimentales ont ete effectuees avec les melanges eau-hydrogene, eau-azote, ethanol-azote (liquides mouillants) introduits dans un tube d'acier inoxydable de 4 mm de diametre interieur, chauffe electriquement sur 320 mm de longueur. On a fait varier le debit de gaz (Reynolds jusqu'a 50 000), le rapport debit en masse liquide, le debit en masse de gaz (jusqu'a 15), la pression (jusqu'a 10 kg/cm{sup 2}), les temperatures (jusqu'a l'ebullition) et le flux de chaleur (jusqu'a 250 W/cm{sup 2}). Deux modes de burnout ont ete observes. On donne une formule de correlation du flux de chaleur provoquant le burnout. On etablit une formule de correlation sans dimension des coefficients d'echanges locaux en utilisant l'analogie entre tranfert de masse et transfert de chaleur. (auteur)}
place = {France}
year = {1960}
month = {Jul}
}
title = {Heat transfer by liquids in suspension in a turbulent gas stream (1960); Transfert de chaleur par liquides entraines dans un ecoulement gazeux turbulent (1960)}
author = {Grison, E, and Commissariat a l'Energie Atomique, Saclay (France).Centre d'Etudes Nucleaires]}
abstractNote = {The introduction of a small volume of liquid into a turbulent gas stream used as cooling agent improves considerably the heat transfer coefficient of the gas. When the turbulent regime is established, one observes in a cylindrical tube two types of flow whether the liquid wets or does not wet the wall. In the first case, one gets on the wall an annular liquid film and droplets in suspension are in the gas stream. In the second case, a fog of droplets is formed without any liquid film on the wall. Experiments were performed with the following mixtures: water-hydrogen, water-nitrogen, ethanol-nitrogen (wetting liquids) introduced into a stainless steel tube of 4 mm ID, electrically heated on 320 mm of length. We varied the gas flow rate (Reynolds until 50000), the rate of the liquid flow rate to gas flow rate (until 15), the pressure (until 10 kg/cm{sup 2}), the temperature (until the boiling point) and the heat flux (until 250 W/cm{sup 2}). Two types of burnout were observed. A formula of correlation of the burnout heat flux is given. Making use of the analogy between mass transfer and heat transfer, a dimensionless formula of correlation of the local heat transfer coefficients is established. (author) [French] L'introduction d'un faible volume de liquide dans un ecoulement gazeux turbulent utilise comme fluide refrigerant permet une amelioration considerable des coefficients d'echanges thermiques que l'on aurait si le gaz etait employe seul (nous avons obtenu un facteur d'amelioration superieur a 10). En regime turbulent etabli, on observe dans un tube deux modes d'ecoulements selon que le liquide mouille ou ne mouille pas la paroi. Dans le premier cas, on obtient sur la paroi un film annulaire liquide et des gouttelettes en suspension dans le coeur gazeux. Dans le deuxieme cas, il se forme un veritable brouillard sans film liquide sur la paroi. Les etudes experimentales ont ete effectuees avec les melanges eau-hydrogene, eau-azote, ethanol-azote (liquides mouillants) introduits dans un tube d'acier inoxydable de 4 mm de diametre interieur, chauffe electriquement sur 320 mm de longueur. On a fait varier le debit de gaz (Reynolds jusqu'a 50 000), le rapport debit en masse liquide, le debit en masse de gaz (jusqu'a 15), la pression (jusqu'a 10 kg/cm{sup 2}), les temperatures (jusqu'a l'ebullition) et le flux de chaleur (jusqu'a 250 W/cm{sup 2}). Deux modes de burnout ont ete observes. On donne une formule de correlation du flux de chaleur provoquant le burnout. On etablit une formule de correlation sans dimension des coefficients d'echanges locaux en utilisant l'analogie entre tranfert de masse et transfert de chaleur. (auteur)}
place = {France}
year = {1960}
month = {Jul}
}