Natural Convection Instabilities Using the Lattice Boltzmann Method: Cavity Aspect Ratio Effect

• Published in: Journal of thermophysics and heat transfer 2023-07, Vol.37 (3), p.606-617
• Main Authors: Berra, El Mehdi, Faraji, Mustapha
• Format: Article
• Language: English
• Subjects: Aspect ratio; Convection heating; Electronic components; Flow simulation; Fluid dynamics; Fluid flow; Free convection; Heat transfer; Simulation; Temperature distribution
• ISSN: 0887-8722; 1533-6808
• DOI: 10.2514/1.T6690

In this paper, the natural convection instability flows in a partial heating cavity filled with air and cooled by the top wall are numerically investigated using the lattice Boltzmann method; and the cavity is partially heated and contains a heat source from below that is presented as an electronic component. To track the cavity aspect ratio effect on the heat transfer over time, first, a series of numerical simulations is completed by varying the aspect ratio of the cavity from A=0.5 to A=5. The results show that the change in aspect ratio has a noticeable impact on the heat transfer behavior, specifically on the temperature distribution in the cavity, and the numerical results obtained indicate two different temperature distribution regimes: a stable steady regime, and a stable oscillatory regime. In the second step, a numerical simulation is done to study the natural convection instability into the cavity for the aspect ratio configuration of A=2. The results show that the cavity structure has an important effect on the heat transfer in the cavity. The lattice Boltzmann method choice as a numerical simulation approach is due to its considerable result in fluid flow simulation and also to its simplicity of implementation, and it has become a suitable alternative method for solving fluid dynamics and thermal problems, as well as challenged traditional methods in many sectors by its simplicity of implementation.