Following De Vahl Davis’ pioneering work, natural convection in an air-filled square cavity became a reference problem for verifying the CFD methods. The 3D simulation results of convection and radiation in a differentially heated cavity have been provided by Colomer et al., however based on the dimensionless parameters he provided, it is difficult to calculate the values of physical quantities like averaged temperature T0 and temperature difference. This has made us validate the problem using ANSYS Fluent based on the benchmark paper entitled “ Three-dimensional numerical simulation of convection and radiation in a differentially heated cavity using the discrete ordinates method “.

Simulation Process

The Benchmark issue is an expansion of the 2D benchmark problem and deals with a 3D air-filled cubic cavity with height H, width W, and depth D. The cavity’s air is seen as a transparent medium. At x=0 and W, the two vertical walls are kept at two distinct but constant temperatures (Th, Tc). Buoyancy-driven air flow in the cavity is governed and affected by radiation effects that is included by Surface to Surface (S2S) radiation model.

Post-processing

The reference paper represents local extreme values for velocity and heat flux. In the third column, when Ra= 10^5, the x and y components of velocity vector are reported: 0.1869 – 0.2865. Also, heat flux of radiative and convective are shown. The CFD Simulation results and the reference paper are compared in the table below:

The simulation of natural convection flow within the 3D cavity demonstrates significant alignment with the reference paper’s findings, validating the model’s accuracy.