Modelling Turbulence Using the Staggered Grid and Simplec Method

Abstract

In a natural convection, local density differences and a resulting pressure gradient accelerate the fluid. In this paper a numerical study of a turbulent, natural convection problem is performed with an incompressible fluid in a rectangular enclosure. At the heated wall, the temperature distribution is a function of temperature gradients. The objective of this study is to conduct a numerical investigation of turbulent natural convection in a 3-D cavity using the staggered grid and the SIMPLEC method. The statisticalaveraging 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 ReynoldsAveraged Navier-stokes (RANS), energy and k- SST turbulent equations are first non-dimensionalized and the resulting equations are discretized using a staggered and solved using SIMPLEC. From the results, both the experimental data and simulation using the staggered grid and SIMPLEC return a non-dimensional temperature of 0.5 at the core of the cavity and almost zero towards the cold and the natural turbulence flow is responsible for temperature distribution. Further, convective mass exchange is dominant in the centre of the enclosure. The investigated Rayleigh number of this study lies at Ra = 1.58.