Study of bioconvection flow in Oldroyd-B nanofluid with motile organisms and effective Prandtl approach

On account of fabrication of nano bio-materials applications in various industrial and technological manufacturing systems, bioconvection in nanofluid has become famous in recent years. This investigation is made by adopting bioconvected flow of Oldroyd-B nanofluid over stretched sheet which assumed to be oscillatory. The periodically moving sheet generates the flow. The thermal radiations effects are also encountered in the energy equation. Three independent variables governed by the flow equations are diminished into two independent variables. The series solution for transformed ordinary differential equations is calculated by homotopy analysis method. In present investigation, thermal radiation for linearized Rosseland's assumption is studied in one parametric approach instead of two parametric approaches. Here, the temperature profile does not depend upon Prandtl number and radiation parameter but combination of these two which is termed as effective Prandtl number. Significance of flow parameters on effective local Nusselt number, local Sherwood number and local motile density number is evaluated in tabular form. It is noted that the temperature of nanoparticles effectively enhanced by increasing buoyancy ratio and Rayleigh number. The concentration profile increases with buoyancy ratio and bioconvected Rayleigh number. The higher values of bio-convected Peclet number lead to be decrement of motile microorganism profile. The results presented here can play effective role for enhancement of efficiency of heat transfer devices and microbial fuel cells. (C) 2019 Elsevier B.V. All rights reserved.