STABILITY ANALYSIS OF BIOCONVECTIVE HEAT TRANSFER IN A SUSPENSION OF GYROTACTIC MICROORGANISMS UNDER VERTICAL VIBRATION

Abstract

Vertical vibration is an important technique to reduce or increase the bioconvective heat transfer. It has great applications in biotechnology, biomedicine, enhancing oil recovery, mixing in microvolumes, analysis of whole body vibration (WBV), and industry. The present study aims to investigate the influence of vertical vibration on the initiation of thermo-bioconvection in a suspension of randomly swimming gyrotactic microorganisms in a shallow thermally stratified horizontal fluid layer. The time-averaged method, linear stability analysis, and single-term Galerkin technique with different boundary layers are employed on the set of field equations. A secular equation is obtained in terms of vibrational and bioconvectional parameters for rigid-rigid and rigid-free boundary conditions. The analysis reported that vertical vibration destabilizes the suspension due to randomly swimming of gyrotactic microorganisms, i.e., enhancing the rate of bioconvective heat transfer. The authors also found that pertinent controlling parameters influence the size of the cell of vibrational thermo-bioconvection. It is observed that the diffusion and average volume of randomly swimming microorganisms affect the bioconvective heat transfer of the vibrational system inversely.