Vertically oscillated gyrotactic bio-thermal convection in a porous media

Abstract

We investigate the onset of gyrotactic bioconvection in a porous fluid layer subject to convective force under the effect of high-frequency oscillation. Differential equations governing the flow for the thermal vibrational bioconvection are formulated using the time-averaging scheme. The instability threshold is investigated for the cases of no-slip boundaries using the Darcy model. The Galerkin technique is invoked to tackle the Eigen value problem and establish an approximation to the analytical results. The instability criterion is analyzed for the non-oscillatory convection along with the relationship between the controlling agencies. The convection is stabilized due to the Péclet number, while the increase in gyrotactic propulsion destabilizes the flow. The stabilizing nature of the vibrational force is significantly affected due to the thermally stratified porous matrix, which induces destabilization. An exciting feature is the destabilizing significance of the thermo–vibrational parameter, which arises due to the coupling of vibrational and thermal properties. Discussions of the results with their physical revelations and comparisons are presented for all the cases.

Keywords

• Thermo-vibrational
• Gyrotactic
• Porous
• Stability
• Biothermal