Thermo-Bioconvection in a Square Porous Cavity Filled by Oxytactic Microorganisms

This paper studies the thermo-bioconvection in a square porous cavity filled by oxytactic microorganisms. The Darcy model with Boussinesq approximation has been used to solve the flow and heat and mass transfer in the porous region. The governing equations formulated in terms of the dimensionless stream function, temperature and concentration have been solved using the finite difference method. Comparison with results from the open literature of the mean Nusselt number for a square cavity filled with a regular porous medium is made. It is shown that the results are in very good agreement. The main objective was to investigate the influence of the traditional Rayleigh number Ra = 10, 100, bioconvection Rayleigh number Rb = 10, 100, Lewis number Le = 1, 10, and Péclet number Pe = 0.1, 1 on the fluid flow and heat and mass transfer. Comprehensive analysis of an effect of these key parameters on the Nusselt and Sherwood numbers at the vertical walls has been conducted.