DOI: 10.1615/ICHMT.2004.CHT-04
ISBN Print: 978-1-56700-174-7
ISSN: 2578-5486
CONTRIBUTION TO ELLIPTIC RELAXATION MODELLING OF TURBULENT NATURAL AND MIXED CONVECTION
ABSTRACT
The paper reports on recent developments in modelling and numerical computations of natural and mixed convection based on newly developed non-linear algebraic heat flux and buoyancy extended stress models in the framework of the eddy-viscosity elliptic-relaxation approach. The DNS based a priori testing of generic cases of turbulent natural convection (the side- and heated from below configurations) demonstrated that significant improvements are obtained in predictions of turbulent heat flux components when compared with more conventional proposals from the literature (including SGDH, GGDH and AFM). The five equations (k - ε - v2 - f - θ2) model is then applied for computation of several 2D and 3D natural and mixed convection flows in turbulent regime. For all simulated cases, good agreements with available experimental and earlier numerical simulations are obtained. It is proved that new model provides a rational compromise between physically sounder wall treatment and computational robustness enabling the use of moderately dense computational grids.