Free convection boundary layer flow past a horizontal flat plate embedded in porous medium filled by nanofluid containing gyrotactic microorganisms

The steady boundary layer free convection flow past a horizontal flat plate embedded in a porous medium filled by a water-based nanofluid containing gyrotactic microorganisms is investigated. The Oberbeck-Boussinesq approximation is assumed in the analysis. The effects of bioconvection parameters on the dimensionless velocity, temperature, nanoparticle concentration and density of motile microorganisms as well as on the local Nusselt, Sherwood and motile microorganism numbers are investigated and presented graphically. In the absence of bioconvection, the results are compared with the existing data in the open literature and found to be in good agreement. The bioconvection parameters strongly influence the heat, mass, and motile microorganism transport rates. (C) 2012 Elsevier Masson SAS. All rights reserved.