Double-Diffusive Bioconvection in a Suspension of Gyrotactic Microorganisms Saturated by Nanofluid

Abstract

This paper focuses on analytical and numerical investigation of double-diffusive bioconvection in a porous media saturated by nanofluid using the modified mass flux condition. Normal mode technique is employed to solve the governing equations of the Brinkman-Darcy model. The Galerkin weighted residual method (singleterm and six-term) is used to obtain numerical solution of the mathematical model. It is found that due to the presence of gyrotactic microorganisms, Rayleigh number is decreased substantially which shows that convection sets in earlier as compared to nanofluid without microorganisms and this destabilizing effect is more predominant for faster swimming microorganisms. modified Darcy number number, Soret parameter, and porosity postpone the onset of the bioconvection, whereas nanoparticle Rayleigh number, bioconvection Rayleigh number, nanoparticle Lewis number, Dufour parameter, Péclet number, and Lewis number pre-pone the onset of bioconvection under certain conditions.

Thermophoresis and Brownian Model of Pseudo-Plastic Nanofluid Flow over a Vertical Slender Cylinder

“…Transport of heat for the ferromagnetic fluid with thermal stratification over a stretching sheet was examined by Muhammad et al [22]. Saini and Sharma [23] extended the application of nanofluids through the investigation of double-diffusive bioconvection. Further extensive research and applications of nanofluids across numerous fields are heat transmission, energy, microequipment, and boiling applications [24][25][26][27][28].…”

Impact of Soret and Dufour on bioconvective flow of nanofluid in porous square cavity

“…Equations (2) and (3) are momentum equations in x and y directions, respectively, based on Darcy–Boussinesq approximation. Equations (4)–(6) represent conservation energy, conservation of solute, and conservation of oxygen concentration, respectively 23 . Equation (7) represents the cell conservation of oxytactic microorganism 10 …”

Investigation of Marangoni bio‐thermal convection in layers of nanofluid with gyrotactic microorganisms

“…He showed that the existence of gyrotactic microorganisms has a destabilizing effect on the system. Some recent analyses of nanofluid behaviour in the presence of gyrotactic microorganisms are given by Tham et al [17], Uddin et al [18], Saini and Sharma [19,20] among others.…”

“…The nanoparticle diameter (expressed in nanometres) satisfies 𝑑 𝑝 ∈[11, 50] for a DW/alumina nanofluid and 𝑑 𝑝 = 29 for a DW/cupric oxide nanofluid, and φ ∈ [0.01, 0.1]. Khanafer and Vafai[38] also proposed that the effective dynamic viscosity follows the constitutive model for nanoparticle diameters (expressed in nanometres) satisfying 𝑑 𝑝 ∈[13, 133] and for Celsius temperatures 𝑇 ∈[20, 70]. Here 𝑎 1 , 𝑎 2 , … , 𝑎 8 and 𝑏 0 , 𝑏 1 , … , 𝑏 8 are constants.…”