Natural convection in two-layer channel near bottom sludge under the influence of daily temperature fluctuations by the Lattice Boltzmann Method

This study investigates the natural convective flow within an horizontal two-layer system driven by daily temperature fluctuations. The upper part of the layer is free of the porous medium, while the porosity is in the lower part. A homogeneous porosity distribution is assumed along the bottom, mimicking the flow near bottom vegetation or sludge. The Lattice Boltzmann Method is employed to solve the problem. The porous medium is simulated using the representative elementary volume (REV) method. An additional set of distribution functions is implemented to capture temperature distribution. Simulation is performed at constant porosity coefficient and at different Darcy number.