In the present study, heat transfer by two-dimensional incompressible nanofluids around four sinusoidal side obstacles in a horizontal channel is numerically analyzed via the lattice Boltzmann method (LBM). The liquid in the channel is a water containing copper nano-sized particles. The viscosity and effective thermal conductivity of the nanoliquid are respectively defined through the Brinkman and Patel approaches. Analysis is run for various magnitudes of the Reynolds number (Re = 100, 200, 400) and nano-sized particles concentration (ϕ = 0, 0.03, 0.05) at different non-dimensional amplitudes (A = 0, 10, 20) of the wavy wall of the sinusoidal obstacles. The effects of changing the distance between the obstacles regarding their arrangement inside the channel are also investigated. The obtained data are presented with reference to the streamlines, temperature and Nusselt numbers profiles. The results indicate that, as the magnitude of the nano-sized particles concentration increases and the distance between the obstacles decreases, the mean Nusselt number rises. In addition, decreasing in the wavy border amplitude results to the thermal transmission enhancement.

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