Nanofluid containing motile gyrotactic microorganisms squeezed between parallel disks

Abstract

Advanced nano and microtechnologies for nano/micro-electronic devices have made substantial advances in the past few years. These technologies are rapidly incorporating advanced fluid media such as nanofluids and biological microorganisms. Inspired by bio-nanofluid applications in medicine, biological systems and biotechnology in the present study, mathematical model is evolved for unsteady bio convective conducting nanofluid along with gyrotactic micro-organisms squeezed between parallel disks. The lower disk and upper disks are solids. The temperature field is improved by the methods of haphazard motion of nanoparticles and thermophoresis parameters. The nano-bio transfer model is written as a series of non-linear partial differential equations that are reduced into a set of ordinary differential equations using suitable transforms. The dimensionless problem is then numerically solved by RK-4th order scheme utilizing MATLAB bvp4c solver’s package to investigate the impact of the squeezing parameter, Hartman number, Brownian motion and thermophoresis parameter on motile microorganism velocity, temperature, nanoparticle concentration, and density. The friction factor, Nusselt number, Sherwood number and microorganism number distributions on Hartman number, thermophoresis and Brownian motion factors are also computed. The Brownian motion and the thermophoresis factors of nanoparticles cause an increment in temperature profiles for both suction and injection. The concentration and motile microorganism are both amplified for the Brownian parameter in the case of injection, whereas they are declined for suction and the opposite trend is observed for the thermophoresis parameter. The motile microorganism is deflated for both suction and injection with thermophoresis parameter. Suction and injection adversely affect the transfer properties at the disks. The resistive magnetic body force prevails in the core zone, resulting in a decrease in velocity. The heat generation in squeeze films with motile microorganisms can be successfully removed with magnetic nanoparticles which require a longer serviceability of the lubrication system, bio-medical systems and need for less maintenance and a longer lifespan approach. The finding is pertinent to novel bio-microsystems that combine nanofluid and the bioconvection phenomenon. The percentage increase in heat, mass, and microorganism transport rates is calculated.