Combined convection heat transfer in a lid driven cavity filled with nanofluids

A simulation study is performed of laminar steady combined convection heat transfer in a lid-driven cavity containing various types of nanofluid (CuO–water nanofluid and Al₂O₃–water nanofluid) at various boundary conditions. The influence of two different types of temperature distributions applied to the cavity's bottom wall is investigated. There are two types of temperature distributions: constant temperature (T_h) and a sinusoidal temperature distribution applied to the bottom wall, which has a higher temperature than the top moving wall (T_c). In both circumstances, the sidewalls are kept adiabatic. The finite element method is utilized for the current issue. The influence of the Richardson number, which ranges from 0.01 to 10, and the volume fraction of nanoparticles, which ranges from 0 to 0.1, on the heat transfer rate has been explored. The influence of the sinusoidal temperature distribution's amplitude and phase angle is also examined. The isotherm and streamline patterns within the cavity are diverse with distinct nanoparticle volume fractions, and the Richardson numbers are presented and analyzed. The numerical findings showed that lowering the Richardson number raises the average Nusselt number. Also, the existence of nanoparticles in pure water increases heat transmission. Additionally, raising the sinusoidal temperature's amplitude increases the average Nusselt number. The results show that the increase of average Nusselt number at (φ = 0, Gr = 10⁴, Pr = 1, Ɣ = 3π/2) for amplitude 0.25, 0.5, 0.75, and 1 is 0.53, 0.9, 1.3, and 1.87, respectively.