| Popis: |
Incompressible, steady-state, boundary layer magneto-bioconvection of a nanofluid\ud (containing motile gyrotactic micro-organisms) over a nonlinear inclined stretching sheet\ud subjected to non-uniform magnetic field is studied theoretically and numerically. This regime\ud is encountered in novel bio-nano-material electroconductive polymeric processing systems\ud currently being considered for third generation organic solar coatings, anti-fouling marine\ud coatings etc. Buongiorno’s two-component nanofluid model is deployed with the OberbeckBoussinesq approximation. Ohmic dissipation (Joule heating) is included. The governing\ud nonlinear partial differential equations are reduced to a system of ordinary differential\ud equations and appropriate similarity transformations. The normalized system of equations with\ud associated boundary conditions features a number of important dimensionless parameters\ud including magnetohydrodynamic body force parameter (M), sheet inclination (δ), Brownian\ud motion nanoscale parameter (Nb), thermophoresis nanoscale parameter (Nt), Richardson\ud number (Ri=GrRe2\ud , where Gr is thermal Grashof number and Re is Reynolds number),\ud buoyancy ratio parameter (Nr), Eckert (viscous dissipation) number (Ec), bioconvection\ud Rayleigh number (Rb), Lewis number (Le), bioconvection Lewis number (Lb), Péclet number\ud (Pe), nonlinear stretching parameter (n) are solved with a variational Finite Element Method\ud (FEM). Validation is conducted with earlier published studies of Khan and Pop (2010) for the\ud case of non-magnetic stretching sheet nanofluid flow without bioconvection. Further validation\ud of the general magnetic bioconvection nanofluid model is achieved with a generalized\ud differential quadrature (GDQ) numerical technique developed by Bég and Kuharat (2017). The\ud response of non-dimensional velocity, temperature, nanoparticle concentration, motile microorganism density function, local skin friction coefficient, Nusselt number, Sherwood number,\ud wall motile density gradient function to variation in physically pertinent values of selected\ud control parameters (representative of real solar bio-nano-magnetic materials manufacturing\ud systems) are studied in detail. Interesting features of the flow dynamics are elaborated and new\ud future pathways for extension of the study identified in bio-magneto-nano polymers (BMNPs)\ud for solar coatings. |
