Numerical simulation of 2D turbulent natural convection of humid air in a cavity filled with solid objects

Draco Iyi, Reaz Hasan, Roger Penlington

Research output: Contribution to journalConference article

3 Citations (Scopus)
9 Downloads (Pure)

Abstract

Natural convection flow in enclosures containing solid objects is important in the design of a wide range of industrial and engineering applications. Numerical calculations were performed for low turbulence double-diffusion convection for humid air inside a rectangular cavity with an aspect ratio of 2:1(height/width) and partially filled with disconnected solid cylindrical objects occupying 15% of the total cavity volume. The vertical walls are maintained at 1.2 and 21 °C and a Rayleigh number of the fluid mixture based on the height of the vertical wall is 1.45 × 109. In the computations, turbulent fluxes of momentum, heat and mass were modelled by a low-Re (Launder-Sharma) κ-□ eddy diffusivity model. Radiation equation was discretised using the discrete ordinate method. Detailed analysis was performed on the flow and heat transfer and on the turbulence quantities within the cavity. The effect of 2D simplification of inherently 3D radiation modelling was carefully scrutinised and calculations carried out with an equivalent emissivity. Variations of average Nusselt number and buoyancy flux are analysed. Profiles of turbulent kinetic energy and turbulent viscosity are studied in detail to observe the net effect on the intensity of turbulence caused by the interactions of radiation with double-diffusive natural convection heat and mass transfer. Particular emphasis was placed on quantifying the proximity of the solid objects to the active walls. It has been found that turbulence is suppressed as the objects get closer to the walls.

Original languageEnglish
Pages (from-to)538-543
Number of pages6
JournalProcedia Engineering
Volume56
DOIs
Publication statusPublished - 1 Jan 2013
Externally publishedYes
Event5th Bangladesh Society of Mechanical Engineers (BSME) International Conference on Thermal Engineering, ICTE 2012 - Dhaka, Bangladesh
Duration: 21 Dec 201223 Dec 2012

Bibliographical note

© 2013 The Authors. Published by Elsevier Ltd.
Open access under CC BY-NC-ND license.

Keywords

  • Double diffusive heat and mass transfer
  • Emissivity
  • Natural convection

ASJC Scopus subject areas

  • Engineering(all)

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