Impact of the Position and Length of the Lid Moving Part on Mixed Convection in Porous Cavities

This study explores mixed convection in a square porous cavity, highlighting the dominant influence of a lid moving part (LMP) on flow dynamics and heat transfer.Numerical simulations, based on the Finite Volume Method, reveal that both the position and length on the LMP strongly affect vortex formation on and thermal performance.When the LMP is shifted and elongated, it induces multiple vortices that reduce the average Nusselt number.However, optimal configurations such as placing the heated wall on the right and adjusting the LMP location can significantly enhance heat transfer.A key finding is that mechanical forcing from the LMP outweighs buoyancy effects, especially at lower Darcy numbers, where heat transfer increase up to 9.5 fold.The study underscores the nonmonotonic influence of LMP geometry, and the interplay between Darcy and Richardson numbers in shaping temperature gradients and flow behavior within porous media.