Numerical investigation of Von Karman swirling bioconvective nanofluid transport from a rotating disk in a porous medium with Stefan blowing and anisotropic slip effects

Abstract

In recent years, significant progress has been made in modern micro- and nanotechnologies related toapplications in micro/nano-electronic devices. These technologies are increasingly utilizing sophisticated fluentmedia to enhance performance. Among the new trends is the simultaneous adoption of nanofluids and biologicalmicro-organisms. Motivated by bio-nanofluid rotating disk oxygenators in medical engineering, in the currentwork, a mathematical model is developed for steady convective Von Karman swirling flow from animpermeable power-law radially stretched disk rotating in a Darcy porous medium saturated with nanofluiddoped with gyrotactic micro-organisms. Anisotropic slip at the wall and blowing effects due to concentrationare incorporated. The nano-bio transport model is formulated using non-linear partial differential equations(NPDEs), which are transformed to a set of similarity ordinary differential equations (SODEs) by appropriatetransformations. The transformed boundary value problem is solved by a Chebyshev collocation method. Theimpact of key parameters on dimensionless velocity components, concentration, temperature and motilemicroorganism density distributions are computed and visualized graphically. Validation with previous studiesis included. It is found that that the effects of suction provide a better enhancement of the heat, mass andmicroorganisms transfer in comparison to blowing. Moreover, physical quantities decrease with higher slipparameters irrespective of the existence of blowing. Temperature is suppressed with increasing thermalslip whereas nanoparticle concentration is suppressed with increasing wall mass slip. Micro-organismdensity number increases with the greater microorganism slip. Radial skin friction is boosted withpositive values of the power law stretching parameter whereas it is decreased with negative values.The converse response is computed for circumferential skin friction, nanoparticle mass transfer rateand motile micro-organism density number gradient. Results from this study are relevant to novelbioreactors, membrane oxygenators, food processing and bio-chromatography