Modelling Turbulent Natural Convection Using the Staggered Grid and k-ω SST

  • K. J. Kimunguyi
  • K. O. Awuor
  • F. K. Gatheri


In this paper, a computational study of turbulent, natural convective flow of an incompressible fluid in a rectangular cavity is done. At the hot wall, the temperature distribution is a function of temperature gradients. The objective of this study is to investigate numerically, turbulent natural convection in a 3-D cavity using the staggered grid and the k- SST model. The statistical-averaging process of the mass, momentum and energy governing equations introduces unknown turbulent correlations into the mean flow equations which represent the turbulent transport of momentum, heat and mass, namely Reynolds stress () and heat flux (), which are modeled using k- SST model. The Reynolds-Averaged Navier-stokes (RANS), energy and k- SST turbulent equations are first non-dimensionalized and the resulting equations are discretized using a staggered grid. From the results, for both the experimental data and simulation using the staggered grid and k- SST model, the discretization error has diminished to zero and the grid independence has been reached. Furthermore, we have reduced computational cost by finding an optimum grid size of the control volume, without compromising with the accuracy of the solution. The investigated Rayleigh number of this study lies at Ra = 1.58.Keywords: turbulence, natural convection, staggered grid, k- SST model