Internal natural convection driven by an orthogonal pair of differentially heated plates

•Internal convection due to orthogonal and differentially heated plates is studied.•The effects of plate–plate and plate–wall temperature are investigated.•Thermal buoyancy and hydrodynamical blockage effects of the plates are discussed.•Convection heat transfer becomes strong when the vertical plate is hotter.•The study also includes the situations wherein the plates are wall mounted.

An internal natural convective flow arising in a closed square cavity due to the presence of two orthogonal and differentially heated plates is studied numerically. The flow is assumed to be laminar and two-dimensional. The Alternating Direction Implicit technique in association with the Successive Over Relaxation method is used to solve the coupled nonlinear governing equations. The heat and fluid flow interactions are studied for various combinations of plate–plate and plate–wall temperature ratios and different positions of the heated plates. When there are two plates with high temperature contrast the heat transfer mechanism inside the cavity is mainly ruled by the hotter one. In general convection heat transfer becomes strengthened when the vertical plate is hotter.