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1.
Nanotechnology ; 35(11)2023 Dec 27.
Article in English | MEDLINE | ID: mdl-38081079

ABSTRACT

In this comprehensive study, the dynamic behavior of a copper-water nanofluid infused with gyrotactic microorganisms, focusing on the effects of Hall current, nanoparticle radius, inter-particle spacing, and multiple slip mechanisms is investigated. Through advanced numerical simulations and rigorous analysis, intricate relationships between the parameters and the suspension's characteristics are uncovered. Comparison of the present results show a good agreement with the published results. The research findings unveil the potential for fine-tuning transport processes, manipulating thermal properties, and controlling dispersion and aggregation in nanofluids. These insights hold promise for a wide array of applications, from enhancing heat exchangers and cooling systems to pioneering biomedical devices utilizing gyrotactic microorganisms for targeted drug delivery and sensing. This study not only advances the fundamental understanding of nanofluid dynamics but also paves the way for innovative developments across various scientific and engineering domains.

3.
Sci Rep ; 12(1): 19821, 2022 Nov 17.
Article in English | MEDLINE | ID: mdl-36396699

ABSTRACT

Bioconvection due to microorganisms is important area of research, considerably importance for environment and sustainable fuel cell technologies. Buongiorno nanofluid model for Cattaneo-Christov heat and mass flux theory taken into account the Oldroyd-B nanofluid and gyrotactic microorganisms in a rotating system with the effects of Hall current, and Darcy porous medium is scrutinized. The constitutive equations of the problem are transformed into nondimensional equations with the help of similarity transformations. Homotopy analysis method is used to obtain the solution. Graphs and table support the comprehesive representation of the achieved results. Radial velocity is reduced with the increasing values of relaxation time, retardation time and magnetic field parameters while heat transfer is augmented with thermal relaxation time parameter. The nanoparticles concentration is reduced with the increasing values of Schmidt number and the gyrotactic microorganisms concentration is enhanced with the increasing values of Peclet number. A nice agreement is obtained while comparing the present results numerically with the published results. The proposed mathematical model is used in biochemical engineering, meteorology, power and transportation production, optoelectronic and sensing microfabrication.

4.
Sci Rep ; 11(1): 19378, 2021 09 29.
Article in English | MEDLINE | ID: mdl-34588473

ABSTRACT

The study concerns with the mechanical characteristics of heat and mass transfer flow of a second grade nanofluid as well as gyrotatic microorganism motion past a thin needle with dipole effect, entropy generation, thermal radiation, Arrhenius activation energy and binar chemical reaction. The governing equations and boundary conditions are simplified by the use of suitable similarity transformations. Homotopy analysis method is implemented to obtain the series solution of non-linear ordinary differential equations. Physical behaviors of heat and mass transfer flow with gyrotatic microorganisms and entropy generation are investigated through the embedded parameters. The nanofluid velocity is enhanced for higher values of the ferromagnetic parameter, local Grashof number, bioconvection Rayleigh number and radiation parameter. The Reynolds number, radiation parameter and Eckert number decrease the nanofluid temperature. The entropy generation is increased with the enhancement of radiation parameter, Eckert number, Lewis number, temperature difference parameter, dimensionless constant parameter, Curie temperature, Prandtl number and concentration difference parameter.

5.
Sci Rep ; 11(1): 19399, 2021 Sep 29.
Article in English | MEDLINE | ID: mdl-34588553

ABSTRACT

In this paper, a numerical study of MHD steady flow due to a rotating disk with mixed convection, Darcy Forchheimer's porous media, thermal radiation, and heat generation/absorption effects are explored. A strong magnetic field is applied in perpendicular direction to the flow which governs the Hall current effects. Homogeneous and heterogeneous reactions are also taken into account. For the simplification of partial differential equations (PDEs) into the nonlinear ordinary differential equations (ODEs), the method of generalized Von Karman similarity transformations is employed, and the resulting non-dimensional ordinary differential equations are solved by using the homotopy analysis method (HAM). Effects of different parameters on the axial, radial and tangential velocity profiles, temperature and concentration of chemical reaction profiles are analyzed and discussed. The present work's remarkable finding is that with the expansion of nanoparticles size, dimensionless constant parameter, local Grashof number, porosity parameter, Hall current, and suction parameter, the nanofluid radial velocity is enhanced. For the higher values of magnetic field parameter, the tangential velocity and nanofluid temperature are enhanced. The magnetic field parameter and the disk thickness coefficient parameter have similar impacts on the axial velocity profile. Heterogeneous chemical reaction parameter decreases the concentration of chemical reaction profile. The nanoparticles volume fraction increases the concentration of chemical reaction profile. Furthermore, the present results are found to be in excellent agreement with previously published work in tabulated form.

6.
Sci Rep ; 11(1): 13576, 2021 06 30.
Article in English | MEDLINE | ID: mdl-34193892

ABSTRACT

This article outlines an analytical analysis of unsteady mixed bioconvection buoyancy-driven nanofluid thermodynamics and gyrotactic microorganisms motion in the stagnation domain of the impulsively rotating sphere with convective boundary conditions. To make the equations physically realistic, zero mass transfer boundary conditions have been used. The Brownian motion and thermophoresis effects are incorporated in the nanofluid model. Magnetic dipole effect has been implemented. A system of partial differential equations is used to represent thermodynamics and gyrotactic microorganisms motion, which is then transformed into dimensionless ordinary differential equations. The solution methodology is involved by homotopy analysis method. The results obtained are based on the effect of dimensionless parameters on the velocity, temperature, nanoparticles concentration and density of the motile microorganisms profiles. The primary velocity increases as the mixed convection and viscoelastic parameters are increased while it decreases as the buoyancy ratio, ferro-hydrodynamic interaction and rotation parameters are increased. The secondary velocity decreases as viscoelastic parameter increases while it increases as the rotation parameter increases. Temperature is reduced as the Prandtl number and thermophoresis parameter are increased. The nanoparticles concentration is increased as the Brownian motion parameter increases. The motile density of gyrotactic microorganisms increases as the bioconvection Rayleigh number, rotation parameter and thermal Biot number are increased.

7.
Sci Rep ; 11(1): 11641, 2021 06 02.
Article in English | MEDLINE | ID: mdl-34078976

ABSTRACT

The behavior of an Oldroyd-B nanoliquid film sprayed on a stretching cylinder is investigated. The system also contains gyrotactic microorganisms with heat and mass transfer flow. Similarity transformations are used to make the governing equations non-dimensional ordinary differential equations and subsequently are solved through an efficient and powerful analytic technique namely homotopy analysis method (HAM). The roles of all dimensionless profiles and spray rate have been investigated. Velocity decreases with the magnetic field strength and Oldroyd-B nanofluid parameter. Temperature is increased with increasing the Brownian motion parameter while it is decreased with the increasing values of Prandtl and Reynolds numbers. Nanoparticle's concentration is enhanced with the higher values of Reynolds number and activation energy parameter. Gyrotactic microorganism density increases with bioconvection Rayleigh number while it decreases with Peclet number. The film size naturally increases with the spray rate in a nonlinear way. A close agreement is achieved by comparing the present results with the published results.

8.
Sci Rep ; 11(1): 11277, 2021 May 28.
Article in English | MEDLINE | ID: mdl-34050201

ABSTRACT

The current study characterizes the effects of Hall current, Arrhenius activation energy and binary chemical reaction on the rotating flow of hybrid nanofluid in two double disks. By the use of suitable similarity transformations, the system of partial differential equations and boundary conditions for hybrid nanofluid are transformed to ordinary differential equations which are solved through optimal homotopy analysis method. The intensified magnetic field and hybrid nanofluid performances are represented in three dimensional model with flow, heat and mass transfer. Radial velocity decreases and tangential velocity increases with the Hall parameter. Temperature rises with high values of rotation parameter while it decreases with the Prandtl number. Nanoparticles concentration enhances with the increments in Arrhenius activation energy parameter and stretching parameter due to lower disk. There exists a close and favorable harmony in the results of present and published work.

9.
Sci Rep ; 11(1): 1692, 2021 Jan 18.
Article in English | MEDLINE | ID: mdl-33462274

ABSTRACT

Analytical analysis of two-dimensional, magnetohydrodynamic, heat and mass transfer flow of hybrid nanofluid incorporating Hall and ion-slip effects and viscous dissipation in the presence of homogeneous-heterogeneous chemical reactions and entropy generation is performed. The governing equations are modified with the help of similarity variables. The reduced resulting nonlinear coupled ordinary differential equations are solved with the help of homotopy analysis method. The effects of all the physical parameters are demonstrated graphically through a detailed analysis. The main outcome of the study is the use of applied strong magnetic field which generates the cross flow of hybrid nanofluid along the z-axis. The numerical comparison to the existing published literature is also provided.

10.
Sci Rep ; 10(1): 19792, 2020 Nov 09.
Article in English | MEDLINE | ID: mdl-33168916

ABSTRACT

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

11.
Sci Rep ; 10(1): 7868, 2020 05 12.
Article in English | MEDLINE | ID: mdl-32398708

ABSTRACT

Nanotechnology research has a huge impact upon biomedicine and at the forefront of this area are micro and nano devices that use active/controlled motion. In this connection, it is focus to investigate steady three dimensional rotating flow with heat and mass transfer incorporating gyrotactic microorganisms. Buongiorno's nanofluid formulation is followed for thermophoresis and Brownian motion, porous space, Arrhenius activation energy and binary chemical reaction with some other effects. An enhanced analytical method is applied to solve the nondimensional equations. The non-dimensional parameters effects on the fields of velocity, temperature, nanoparticles concentration and gyrotactic microorganisms concentration are shown graphically. Velocity decreases while temperature and nanoparticles concentration increase with magnetic field strength. Gyrotatic microorganisms motion becomes slow with rotation parameter. Due to rotation, the present problem can be applied in microbial fuel cells, food processing, microbiology, biotechnology and environmental sciences, electric power generating and turbine systems, computer disk drives, mass spectromentries and jet motors.

12.
Sci Rep ; 10(1): 4448, 2020 03 10.
Article in English | MEDLINE | ID: mdl-32157121

ABSTRACT

Buongiorno's nanofluid model is followed to study the bioconvection in two stretchable rotating disks with entropy generation. Similarity transformations are used to handle the problem equations for non-dimensionality. For the simulation of the modeled equations, Homotopy Analysis Method is applied. The biothermal system is explored for all the embedded parameters whose effects are shown through different graphs. There exists interesting results due to the effects of different parameters on different profiles. Radial velocity decreases with increasing stretching and magnetic field parameters. Temperature increases with Brownian motion and thermophoresis parameters. Nanoparticles concentration decreases on increasing Lewis number and thermophoresis parameter while motile gyrotactic microorganisms profile increases with increasing Lewis and Peclet numbers. Convergence of the solution is found and good agreement is obtained when the results are compared with published work.

13.
Sci Rep ; 10(1): 1226, 2020 Jan 27.
Article in English | MEDLINE | ID: mdl-31988289

ABSTRACT

The Arrhenius activation energy and binary chemical reaction are taken into account to consider the magnetohydrodynamic mixed convection second grade nanofluid flow through a porous medium in the presence of thermal radiation, heat absorption/generation, buoyancy effects and entropy generation. The items composing of the governing systems are degenerated to nonlinear ordinary differential equations by adopting the appropriate similarity transformations which are computed through Runge-Kutta-Fehlberg (RKF) numerical technique along with Shooting method. The solution is manifested through graphs which provides a detailed explanations of each profile in terms of involved parameters effects. The compared results maintain outstanding approach to the previous papers.

14.
Entropy (Basel) ; 21(2)2019 Feb 01.
Article in English | MEDLINE | ID: mdl-33266855

ABSTRACT

Chemical reaction in mixed convection magnetohydrodynamic second grade nanoliquid thin film flow through a porous medium containing nanoparticles and gyrotactic microorganisms is considered with entropy generation. The stratification phenomena, heat and mass transfer simultaneously take place within system. Microorganisms are utilized to stabilize the suspended nanoparticles through bioconvection. For the chemical reaction of species, the mass transfer increases. The governing equations of the problem are transformed to nonlinear differential equations through similarity variables, which are solved through a well known scheme called homotopy analysis method. The solution is expressed through graphs and illustrations which show the influences of all the parameters. The residual error graphs elucidate the authentication of the present work.

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