Résumé:
A numerical study is conducted to investigate the transport mechanism of laminar mixed
convection in a shear and buoyancy driven cavity having a locally heated lower wall and
moving cooled sidewalls. Effort is focused on the interaction of forced convection with
natural convection. Discretisation of the governing equations is achieved through a finite
difference method. The third order upwind scheme for the convective derivative turns out to
be the most accurate scheme. Parametric studies on the effect of mixed convection parameter,
Gr/Re² (also referred as Richardson number, Ri) in the range 0.1 – 100.
Three different regimes are observed with increasing Ri. When the forced convection
dominates the flow consists of two symmetrical cells. For a precise interval of this number,
this symmetry disappears. Starting from a critical value of the Richardson number, we noted
an abrupt reduction in the number of average Nusselt as well as the apparition of four cells.
