Numerical study on free convection of cold water in a square porous cavity heated with sinusoidal wall temperature

Purpose The aim of the present study is to analyze the natural convection flow and heat transfer of cold water around °C in a square porous cavity. The horizontal walls of cavity are adiabatic, and the vertical walls are maintained at different temperatures. The right side wall is maintained at temperature θc, and the left side wall is maintained at sinusoidal temperature distribution. Design/methodology/approach The Brinkman–Forchheimer-extended Darcy model for porous medium is used to study the effects of density inversion parameter, Rayleigh number and impact of Darcy number and porosity. The finite volume method is used to solve the governing equations. Findings The heat transfer rate is increased on increasing the Darcy number and porosity. Also, the convective heat transfer rate is decreased first and then increased on increasing the density inversion parameter. Research limitations/implications The numerical computations have been carried out for the Darcy number ranging of 10(−4) ≤ Da ≤ 10(−1), the porosity ranging of 0.4 ≤ ε ≤ 0.8 and the density inversion parameter ranging of 0 ≤ Tm ≤ 1 and keeping Ra = 106. Practical implications The results can be used in the cooling of electronic components, thermal storage system and in heat exchangers. Originality/value The choice of consideration of sinusoidal heating and density maximum effect produces good result in flow field and temperature distribution. The obtained results can be used in various fields.

Numerical Simulation of Natural Convection of Water Near Its Density Maximum Around a Cylinder Inside a Concentric Triangular Enclosure

In this paper, a series of numerical simulations for natural convection of water near its maximum-density around a cylinder inside a concentric triangular enclosure were conducted using finite volume method. The effects of the density inversion parameter, the aspect ratio, the Rayleigh number and the inclination angle on natural convection were discussed. Furthermore, the flow and temperature fields, the local and average Nusselt numbers at different parameters were obtained and analyzed. The results show that the flow pattern and temperature distribution are unique for various density inversion parameters and inclination angles. The density inversion parameter, the aspect ratio, the Rayleigh number all have significant effects on the overall heat transfer rates, except for the inclination angle. The present results can also contribute further information on the natural convection of non-Boussinesq fluid in enclosures.