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Natural convection flow in a square cavity revisited: Laminar and turbulent models with wall functions
Author(s) -
Barakos G.,
Mitsoulis E.,
Assimacopoulos D.
Publication year - 1994
Publication title -
international journal for numerical methods in fluids
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.938
H-Index - 112
eISSN - 1097-0363
pISSN - 0271-2091
DOI - 10.1002/fld.1650180705
Subject(s) - nusselt number , laminar flow , turbulence , natural convection , mechanics , mathematics , rayleigh number , finite volume method , heat transfer , physics , reynolds number
Numerical simulations have been undertaken for the benchmark problem of natural convection flow in a square cavity. The control volume method is used to solve the conservation equations for laminar and turbulent flows for a series of Rayleigh numbers ( Ra ) reaching values up to 10 10 . The k ‐ϵ model has been used for turbulence modelling with and without logarithmic wall functions. Uniform and non‐uniform (stretched) grids have been employed with increasing density to guarantee accurate solutions, especially near the walls for high Ra ‐values. ADI and SIP solvers are implemented to accelerate convergence. Excellent agreement is obtained with previous numerical solutions, while some discrepancies with others for high Ra ‐values may be due to a possibly different implementation of the wall functions. Comparisons with experimental data for heat transfer (Nusselt number) clearly demonstrates the limitations of the standard k ‐ϵ model with logarithmic wall functions, which gives significant overpredictions.