Magneto-bioconvection flow in a porous annulus between circular cylinders containing oxytactic microorganisms and NEPCM
Noura Alsedais, Amal Al-Hanaya, Abdelraheem M. Aly
Abstract
Purpose This paper aims to investigate magnetic impacts on bioconvection flow within a porous annulus between an outer cylinder and five inner cylinders. The annulus is filled by oxytactic microorganisms and nano-encapsulated phase change materials. Design/methodology/approach The modified ISPH method based on the time-fractional derivative is applied to solve the regulating equations in Lagrangian dimensionless forms. The pertinent factors are bioconvection Rayleigh number Ra b (1–100), circular cylinder’s radius R c (0.1–0.3), fractional time derivative α (0.95–1), Darcy parameter Da (10 −5 –10 −2 ), nanoparticle parameter ϕ (0–0.1), Hartmann number Ha (0–50), Lewis number Le (1–20), Peclet number Pe (0.1–0.75), s (0.1–0.9), number of cylinders N Cylinders (1–4), Rayleigh number Ra (10 3 –10 6 ) and fusion temperature θ f (0.005–0.9). Findings The simulations revealed that there is a strong enhancement in the velocity field according to an increase in Ra b . The intensity and location of the phase zone change in response to changes in θ f . The time-fractional derivative a acting on a nanofluid velocity and flow characteristics in an annulus. The number of embedded cylinders N Cylinders is playing a significant role in the cooling processes and as N Cylinders increases from 1 to 4, the velocity field’s maximum reduces by almost 33.3%. Originality/value The novelty of this study is examining the impacts of the magnetic field and the presence of several numbers of embedded cylinders on bioconvection flow within a porous annulus between an outer cylinder and five inner cylinders.