Optical thickness effect on natural convection in a vertical channel containing a gray gas

I. Zavala-Guillén*, J. Xamán, C. Salinas, K. A.R. Ismail, I. Hernández-Pérez, I. Hernández-López

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

2 Scopus citations

Abstract

The effect of radiation on natural convection heat transfer in a vertical parallel-plate channel with asymmetric heating, considering the radiation effects for both walls and participating air is presented. The channel is formed by one vertical wall heated by a uniform heat flux and by a vertical adiabatic plate. The governing equations of laminar natural convection and radiative transfer are solved by the finite volume method (FVM) and by the discrete ordinates method (DOM), respectively. The code was validated and verified with data reported in the literature. The effect of optical thickness (τ), channel width (b) and wall emissivity (εh) on the heat transfer and mass flow are investigated. The mass flow of the channel for τ=0.1 is up to 42% greater than that obtained for a transparent medium (τ=0.0). When τ=0.1, the average temperature difference between the air at the inlet and air at the outlet of the channel decreases up to 75% due to the increase of b from 0.02 to 0.10 m. Varying εh from 0.1 to 0.9 increases the radiative heat flux at the heated wall up to 72% and the mass flow rate increases up to 29%. A set of correlations were obtained for the mass flow, average convective Nusselt number and average radiative Nusselt number.

Original languageEnglish
Pages (from-to)510-519
Number of pages10
JournalInternational Journal of Heat and Mass Transfer
Volume107
DOIs
StatePublished - 1 Apr 2017

Bibliographical note

Funding Information:
C. Salinas wishes to thanks for the financial support grant # 2016/01493-9 , São Paulo Research Foundation (FAPESP).

Funding Information:
I. Zavala-Guillén would like to thanks TWAS-CNPQ program for the financial support during her stay at UNICAMP .

Funding Information:
The authors are grateful to Consejo Nacional de Ciencia y Tecnología (CONACYT) whose financial support made this work possible.

Publisher Copyright:
© 2016 Elsevier Ltd

Keywords

  • DOM
  • Natural convection
  • Participating media
  • Vertical channel

Fingerprint

Dive into the research topics of 'Optical thickness effect on natural convection in a vertical channel containing a gray gas'. Together they form a unique fingerprint.

Cite this