Numerical study of bioconvection flow of nanofluids using non-Fourier’s heat flux and non-Fick’s mass flux theory

Abstract

The characteristics of buoyancy-driven convection of nanofluid stream containing motile gyrotactic micro-organisms over a continuous heated surface are explored. The benefits of including micro-organisms to the suspension incorporate micro-scale mixing and foreseen enhanced stability of nanofluid. For heat transfer and mass transfer processes, non-Fourier’s heat flux theory and non-Fick’s mass flux theory are employed. This theory is actively under investigation to resolve some drawbacks of the famous Fourier’s Law and Fick’s Law. The modified parameters in conventional laws are thermal and solutal relaxation times, respectively. The governing equations are remodeled using appropriate similarity transformations into a system of coupled ordinary differential equations. Finite Element Methodology is used to obtain the solution of nonlinear coupled differential equations. The governing equations are associated with dimensionless parameters like [Formula: see text]. The influence of these parameters is analyzed graphically on velocity, temperature profile, concentration profile and density of micro-organisms. The computational results obtained reveal that the temperature profile and concentration profile have an inverse relationship with thermal relaxation and solutal relaxation time, respectively. Furthermore, the velocity increases with increasing values of the Richardson number, while a reverse pattern is observed for bioconvection Rayleigh number and Buoyancy ratio parameter.