Natural convection heat transfer of microemulsion phase-change-material slurry in rectangular cavities heated from below and cooled from above

H. Inaba, C. Dai, Akihiko Horibe

Research output: Contribution to journalArticle

63 Citations (Scopus)

Abstract

An experimental study has been conducted in dealing with natural convection heat transfer characteristics of microemulsion slurry in rectangular enclosures. The microemulsion slurry used in the present experiment was composed of water, surfactant, and fine particles of phase-change-material (PCM). The PCM mass concentration of the microemulsion slurry was varied from a maximum 30 mass% to a diluted minimum 5 mass%, and the experiments have been done separately in three subdivided temperature ranges of the dispersed PCM particles in a solid phase, two phases (coexistence of solid and liquid) and a liquid phase. The results showed that the Nusselt number increased slightly with the PCM mass concentration for the slurry in solid phase. In the phase change temperature range, the Nusselt number increased with an increase in PCM mass concentration of the slurry at low Rayleigh numbers, while it decreased with increasing PCM mass concentration of the slurry at high Rayleigh numbers. There was not much difference in natural heat transfer characteristics of the PCM slurry with low PCM concentrations (<10 mass%), however, the difference was getting greater with increasing the PCM concentration, especially for the enclosure at a lower aspect ratio (width/height of the rectangular enclosure). The enclosure height was varied from 5.5 to 24.6 mm under a fixed width and depth of 120 mm. Hence, the experiments were performed for a wide range of modified Rayleigh number from 3 × 102 to 1.0 × 107. The correlation generalized for the PCM slurry in a single phase was derived in the form of Nu = 0.22(1 - C1Cme-C2AR) Ra1/(3n+1), where C1 and C2 were the optimum fitting constants obtained by the least square method. While the PCM was in a phase changing region, the correlation could be expressed as Nu = 0.22(1 - C1Cm e-C2AR)Ra1/(3n+1)Ste-0.25, where the Ste was the modified Stefan number.

Original languageEnglish
Pages (from-to)4427-4438
Number of pages12
JournalInternational Journal of Heat and Mass Transfer
Volume46
Issue number23
DOIs
Publication statusPublished - Nov 2003

Fingerprint

phase change materials
Phase change materials
Microemulsions
Natural convection
free convection
heat transfer
Heat transfer
cavities
enclosure
Enclosures
Rayleigh number
Nusselt number
solid phases
low aspect ratio
Experiments
Liquids
least squares method
Surface-Active Agents
Aspect ratio
liquid phases

ASJC Scopus subject areas

  • Fluid Flow and Transfer Processes
  • Energy(all)
  • Mechanical Engineering

Cite this

@article{d94712aee8a24b10a006a0ad8708cceb,
title = "Natural convection heat transfer of microemulsion phase-change-material slurry in rectangular cavities heated from below and cooled from above",
abstract = "An experimental study has been conducted in dealing with natural convection heat transfer characteristics of microemulsion slurry in rectangular enclosures. The microemulsion slurry used in the present experiment was composed of water, surfactant, and fine particles of phase-change-material (PCM). The PCM mass concentration of the microemulsion slurry was varied from a maximum 30 mass{\%} to a diluted minimum 5 mass{\%}, and the experiments have been done separately in three subdivided temperature ranges of the dispersed PCM particles in a solid phase, two phases (coexistence of solid and liquid) and a liquid phase. The results showed that the Nusselt number increased slightly with the PCM mass concentration for the slurry in solid phase. In the phase change temperature range, the Nusselt number increased with an increase in PCM mass concentration of the slurry at low Rayleigh numbers, while it decreased with increasing PCM mass concentration of the slurry at high Rayleigh numbers. There was not much difference in natural heat transfer characteristics of the PCM slurry with low PCM concentrations (<10 mass{\%}), however, the difference was getting greater with increasing the PCM concentration, especially for the enclosure at a lower aspect ratio (width/height of the rectangular enclosure). The enclosure height was varied from 5.5 to 24.6 mm under a fixed width and depth of 120 mm. Hence, the experiments were performed for a wide range of modified Rayleigh number from 3 × 102 to 1.0 × 107. The correlation generalized for the PCM slurry in a single phase was derived in the form of Nu = 0.22(1 - C1Cme-C2AR) Ra1/(3n+1), where C1 and C2 were the optimum fitting constants obtained by the least square method. While the PCM was in a phase changing region, the correlation could be expressed as Nu = 0.22(1 - C1Cm e-C2AR)Ra1/(3n+1)Ste-0.25, where the Ste was the modified Stefan number.",
author = "H. Inaba and C. Dai and Akihiko Horibe",
year = "2003",
month = "11",
doi = "10.1016/S0017-9310(03)00289-8",
language = "English",
volume = "46",
pages = "4427--4438",
journal = "International Journal of Heat and Mass Transfer",
issn = "0017-9310",
publisher = "Elsevier Limited",
number = "23",

}

TY - JOUR

T1 - Natural convection heat transfer of microemulsion phase-change-material slurry in rectangular cavities heated from below and cooled from above

AU - Inaba, H.

AU - Dai, C.

AU - Horibe, Akihiko

PY - 2003/11

Y1 - 2003/11

N2 - An experimental study has been conducted in dealing with natural convection heat transfer characteristics of microemulsion slurry in rectangular enclosures. The microemulsion slurry used in the present experiment was composed of water, surfactant, and fine particles of phase-change-material (PCM). The PCM mass concentration of the microemulsion slurry was varied from a maximum 30 mass% to a diluted minimum 5 mass%, and the experiments have been done separately in three subdivided temperature ranges of the dispersed PCM particles in a solid phase, two phases (coexistence of solid and liquid) and a liquid phase. The results showed that the Nusselt number increased slightly with the PCM mass concentration for the slurry in solid phase. In the phase change temperature range, the Nusselt number increased with an increase in PCM mass concentration of the slurry at low Rayleigh numbers, while it decreased with increasing PCM mass concentration of the slurry at high Rayleigh numbers. There was not much difference in natural heat transfer characteristics of the PCM slurry with low PCM concentrations (<10 mass%), however, the difference was getting greater with increasing the PCM concentration, especially for the enclosure at a lower aspect ratio (width/height of the rectangular enclosure). The enclosure height was varied from 5.5 to 24.6 mm under a fixed width and depth of 120 mm. Hence, the experiments were performed for a wide range of modified Rayleigh number from 3 × 102 to 1.0 × 107. The correlation generalized for the PCM slurry in a single phase was derived in the form of Nu = 0.22(1 - C1Cme-C2AR) Ra1/(3n+1), where C1 and C2 were the optimum fitting constants obtained by the least square method. While the PCM was in a phase changing region, the correlation could be expressed as Nu = 0.22(1 - C1Cm e-C2AR)Ra1/(3n+1)Ste-0.25, where the Ste was the modified Stefan number.

AB - An experimental study has been conducted in dealing with natural convection heat transfer characteristics of microemulsion slurry in rectangular enclosures. The microemulsion slurry used in the present experiment was composed of water, surfactant, and fine particles of phase-change-material (PCM). The PCM mass concentration of the microemulsion slurry was varied from a maximum 30 mass% to a diluted minimum 5 mass%, and the experiments have been done separately in three subdivided temperature ranges of the dispersed PCM particles in a solid phase, two phases (coexistence of solid and liquid) and a liquid phase. The results showed that the Nusselt number increased slightly with the PCM mass concentration for the slurry in solid phase. In the phase change temperature range, the Nusselt number increased with an increase in PCM mass concentration of the slurry at low Rayleigh numbers, while it decreased with increasing PCM mass concentration of the slurry at high Rayleigh numbers. There was not much difference in natural heat transfer characteristics of the PCM slurry with low PCM concentrations (<10 mass%), however, the difference was getting greater with increasing the PCM concentration, especially for the enclosure at a lower aspect ratio (width/height of the rectangular enclosure). The enclosure height was varied from 5.5 to 24.6 mm under a fixed width and depth of 120 mm. Hence, the experiments were performed for a wide range of modified Rayleigh number from 3 × 102 to 1.0 × 107. The correlation generalized for the PCM slurry in a single phase was derived in the form of Nu = 0.22(1 - C1Cme-C2AR) Ra1/(3n+1), where C1 and C2 were the optimum fitting constants obtained by the least square method. While the PCM was in a phase changing region, the correlation could be expressed as Nu = 0.22(1 - C1Cm e-C2AR)Ra1/(3n+1)Ste-0.25, where the Ste was the modified Stefan number.

UR - http://www.scopus.com/inward/record.url?scp=0042322724&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0042322724&partnerID=8YFLogxK

U2 - 10.1016/S0017-9310(03)00289-8

DO - 10.1016/S0017-9310(03)00289-8

M3 - Article

AN - SCOPUS:0042322724

VL - 46

SP - 4427

EP - 4438

JO - International Journal of Heat and Mass Transfer

JF - International Journal of Heat and Mass Transfer

SN - 0017-9310

IS - 23

ER -