a b s t r a c t
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.