EFFECTS OF A MOVING THERMAL-WAVE ON BENARD CONVECTION IN A HORIZONTALSATURATED POROUS LAYER

A numerical study is carried out on the natural convection taking plac e in a horizontal saturated porous layer. A sinusoidal temperature dis tribution, as a moving wave, is superposed on the hot temperature of t he lower plate. The imposed wavelength of this perturbation is equal t o the wavelength of incipient Benard cells. For a given Rayleigh numbe r R, results show that the Benard cells move with the imposed wave if the velocity of the latter remains below a critical value. Beyond this critical value, there is still an entrainment of the cells, but at a much lower rate. Further, the cell motion is irregular and time period ic.