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ISSN Online: 2377-424X

ISBN Print: 978-1-56700-421-2

International Heat Transfer Conference 15
August, 10-15, 2014, Kyoto, Japan

Multi-scale Second Moment Modelling of Turbulence and Heat Transfer in Porous Media

Get access (open in a dialog) DOI: 10.1615/IHTC15.ttr.008416
pages 9271-9284

Resumo

To predict turbulence and heat transfer in porous media, double (volume and Reynolds) averaged transport equations are considered. In the momentum equation, there appear unknown terms which are namely the dispersive covariance and the volume averaged Reynolds stress that is split into the macro-scale Reynolds stress and the micro-scale Reynolds stress. Although an algebraic model is applied to the dispersive covariance, to obtain the Reynolds stress, a second moment closure is applied to the volume averaged Reynolds stress, coupled with a two-equation k − ε eddy viscosity model for the micro-scale Reynolds stress. For solving scalar fields, a two-energy equation model, which solves the energy of solid and fluid phases, is developed to consider non equilibrium energy fields between the energy of solid and fluid phases. In the double averaged scalar transport equations, two kinds of scalar fluxes (the dispersion heat flux and the volume averaged turbulent heat flux which is split into the macro-scale and the micro-scale turbulent fluxes) and the energy exchange terms (wall heat transfer and tortuosity) between fluid and solid phases come out. In this study, algebraic models of the volume averaged turbulent heat flux and wall heat transfer terms are discussed. The proposed models of turbulence and heat transfer are evaluated in fully developed square rod array flows. The results suggest that the present models are promising.