Large eddy simulations of a turbulent thermal plume

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Abstract

Large eddy simulations of a three-dimensional turbulent thermal plume in an open environment have been carried out using a self-developed parallel computational fluid dynamics code SMAFS (smoke movement and flame spread) to study the thermal plume's dynamics including its puffing, self-preserving and air entrainment. In the simulation, the sub-grid stress was modeled using both the standard Smagorinsky and the buoyancy modified Smagorinsky models, which were compared. The sub-grid scale (SGS) scalar flux in the filtered enthalpy transport equation was modeled based on a simple gradient transport hypothesis with constant SGS Prandtl number. The effect of the Smagorinsky model constant and the SGS Prandtl number were examined. The computation results were compared with experimental measurements, thermal plume theory and empirical correlations, showing good agreement. It is found that both the buoyancy modification and the SGS turbulent Prandtl number have little influence on simulation. However, the SGS model constant C (s) has a significant effect on the prediction of plume spreading, although it does not affect much the prediction of puffing.

Details

Authors
  • Zhenghua Yan
Organisations
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Building Technologies
Original languageEnglish
Pages (from-to)503-514
JournalHeat and Mass Transfer
Volume43
Issue number6
Publication statusPublished - 2007
Publication categoryResearch
Peer-reviewedYes