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Effect of several heated interior bodies on turbulent natural convection in enclosures

Nouri Borujerdi, A ; Sharif University of Technology | 2019

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  1. Type of Document: Article
  2. DOI: 10.24200/sci.2018.20588
  3. Publisher: Sharif University of Technology , 2019
  4. Abstract:
  5. In this study, turbulent natural convection in a square enclosure including one or four hot and cold bodies is numerically investigated in the range of Rayleigh numbers of 1010 < Ra < 1012. The shape of the internal bodies is square or rectangular with the same surface areas and different aspect ratios. In all cases, the horizontal walls of the enclosure are adiabatic, and the vertical ones are isothermal. It is desired to investigate the influence of different shapes and arrangements of internal bodies on the heat transfer rate inside the enclosure with wide-ranging applications such as ventilation of buildings, electronic cooling, and industrial cold box packages. Governing equations, including Reynolds-averagedNavier-Stokes equations, have been solved numerically with finite volume method and k - e turbulence model in a staggered grid. The boundary condition for the turbulence model is based on the standard wall function approach. The strongly implicit method is employed to solve the discretized systems of algebraic equations with a remarkable rate of convergence. The effects of several parameters, such as the distance between the bodies, aspect ratio, and Rayleigh number, on the heat transfer rate have been investigated. The most noticeable change in the heat transfer rate at high values of Rayleigh numbers is associated with alteration in the distance between square bodies. Moreover, the horizontal installation of rectangular bodies with h/w = 1/3 is accompanied by a maximum reduction of heat transfer at low Rayleigh numbers. The present results have been compared with previous experimental and numerical works regarding enclosures with or without internal bodies. Then, reasonable agreement is observed. © 2019 Sharif University of Technology. All rights reserved
  6. Keywords:
  7. Enclosure ; Interior bodies ; Algebra ; Aspect ratio ; Electronic cooling ; Enclosures ; Finite volume method ; Numerical methods ; Wall function ; Walls (structural partitions) ; Discretized systems ; Function approaches ; Governing equations ; Heat transfer rate ; K-E turbulence model ; Rate of convergence ; Turbulent natural convection ; Wide-ranging applications ; Natural convection ; Adiabatic process ; Boundary condition ; Heat transfer ; Numerical method ; Parameter estimation ; Rayleigh number ; Turbulent flow
  8. Source: Scientia Iranica ; Volume 26, Issue 3B , 2019 , Pages 1335-1349 ; 10263098 (ISSN)
  9. URL: http://scientiairanica.sharif.edu/article_20588.html