Thermal-phototactic bioconvection in a forward scattering algal suspension

TL;DR

This study explores how thermal gradients and forward scattering influence bioconvection in an algal suspension, revealing conditions that stabilize or destabilize the flow based on illumination and heating directions.

Contribution

It introduces a linear stability analysis of thermal-phototactic bioconvection considering anisotropic scattering and different heating configurations.

Findings

Forward scattering enhances bioconvective stability.

Heating from above stabilizes the system.

Heating from below promotes instability.

Abstract

Bioconvection induced by phototaxis and thermal gradients in an anisotropic (forward) scattering algal suspension is investigated in this article. The suspension is illuminated by collimated irradiation from above and heated either from top or bottom. The linear theory is deployed on the steady state of the proposed bioconvective system and resulting eigen value problem is solved using fourth-order accurate finite-difference scheme based on Newton-Raphson-Kantorovich iteration. The results indicate that the forward scattering and heating from above (or cooling from below) in an algal suspension enhance bioconvective stability. On the other hand, heating from below enhance bioconvective instability for a fixed forward scattering coefficient.