Convection naturelle dans une cavité carrée avec des parois verticales soumises à des températures périodiques

The laminar natural convection in a square cavity submitted to different heating modes on its vertical walls, is investigated numerically. The temperature of the heated wall is varied sinusoidally with time while the temperature of the opposite vertical wall is either maintained constant or varied sinusoidally with time. The parameters of the study are the amplitude of the variable temperature(s) (0 ≤ a ≤ 0.8), its (their) period (0.001 ≤ τ < 1), the Rayleigh number (10⁴ ≤ Ra ≤ 10⁶) and the Prandtl number (Pr = 0.7). For adequate combinations of these parameters, the variation with time of the two imposed temperatures gives the possibility to control the heat transfer through the cold boundary of the cavity.