Enhancement of natural convection for improvement of Trombe wall performance. An experimental study

Abderrahmane Baïri, A Martin Garin, Kemi Adeyeye, Kaming She, J.A. Millán-García

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

This experimental work shows that the natural convective heat transfer in the active enclosure of a conventional Trombe wall assembly is enhanced by the interposition of transparent and vertical partitions. Quantification of the average Nusselt number corresponding to both versions with and without partitions was carried out by means of a 1/5 scale assembly. The glass cover is maintained isothermal at cold temperature while the active wall generates a variable heat flux simulating the incident solar radiation. The distance between the two active and parallel walls is variable. Four ratios between this distance and the height of the wall are considered, associated with a wide range of Rayleigh number reaching 4.1×109. An error calculation is carried out for all the processed configurations, taking into account the experimental uncertainties of the measured physical parameters. The maximum error found on the average Nusselt number is low, of about 5%. Measurements made by means of an interstitial medium without partitions are consistent with the results of other work carried out by experimental and numerical approaches in specific ranges of Rayleigh number. This study reveals the partitions effectiveness, since the natural convective heat transfer's increase lies between 10.0% and 14.4% according to the considered configuration. Correlations are proposed in the present work in order to calculate the average natural convective Nusselt number for the conventional Trombe wall without partitions and for its improved version, for any aspect ratio and in the whole range of the considered Rayleigh number. They contribute to the optimization of the thermal design of this interesting assembly.
Original languageEnglish
Article number109788
JournalEnergy and Buildings
Volume211
Early online date17 Jan 2020
DOIs
Publication statusPublished - 15 Mar 2020

Keywords

  • Architecture
  • Experimental heat transfer
  • High rayleigh number
  • Natural convection
  • Performance enhancement
  • Thermal measurements
  • Trombe wall

ASJC Scopus subject areas

  • Civil and Structural Engineering
  • Building and Construction
  • Mechanical Engineering
  • Electrical and Electronic Engineering

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