Effect of internal-heating on weakly non-linear stability analysis of Rayleigh–Bénard convection under g-jitter

In this paper, we study the combined effect of internal-heating and time-periodic gravity modulation on thermal instability in a viscous fluid layer, heated from below. The time-periodic gravity modulation, considered in this problem can be realized by vertically oscillating the fluid layer. A weak non-linear stability analysis has been performed by using power series expansion in terms of the amplitude of gravity modulation, which is assumed to be small. The Nusselt number has been obtained in terms of the amplitude of convection which is governed by the non-autonomous Ginzburg–Landau equation derived for the stationary mode of convection. Effects of various parameters such as internal Rayleigh number, Prandtl number, and amplitude and frequency of gravity modulation have been analysed on heat transport. It is found that the response of the convective system to the internal Rayleigh number is destabilizing. Further, it is found that the heat transport can be controlled by suitably adjusting the external parameters of the system.

••Effect of internal heating is studied on fluid layer under gravity modulation.••Weak non-linear analysis of thermal instability has been done.••Sinusoidal time-periodic gravity modulation has been considered.••The Nusselt number has been obtained in terms of the amplitude of convection.••Effects of various parameters have been investigated.