Lattice Boltzmann simulation of natural convection heat transfer of a nanofluid in a L-shape enclosure with a baffle

Abstract In the present study, the fluid flow and heat transfer of a Cu-water nanofluid in a L-shaped enclosure with a baffle is numerically simulated using the Lattice Boltzmann Method (LBM). The implementation of different baffle combinations with the L shape cavity is the novel contribution of this study. The effect of baffle configuration on natural convection in different parameter ranges of Rayleigh number ( 10 3 – 10 5 ) and nanoparticle volume fraction (0–0.05) is investigated. Various baffle configuration cases are examined based on baffle length (L) and position (S). The baffled L shape results are also compared to the results obtained from a L shape without a baffle that were also achieved in this study and are validated with excellent agreement with existing data. Different models are used for evaluating the dynamic viscosity and thermal conductivity, to compare the effects of nanofluid properties. The results show that at low Rayleigh numbers ( 10 3 – 10 4 ), the addition of baffle always enhances natural convection. In high Rayleigh numbers ( 10 5 ), only the longer baffle (L = 0.30 m) can improve natural convection regardless of its positioning. The longer baffle is always more effective with proper positioning (S = 0.4 m) and the case C baffle configuration (L = 0.30 m, S = 0.4 m) is the most effective in all conditions.