scholarly journals Bioconvection flow in accelerated couple stress nanoparticles with activation energy: bio-fuel applications

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sami Ullah Khan ◽  
Kamel Al-Khaled ◽  
A. Aldabesh ◽  
Muhammad Awais ◽  
Iskander Tlili
Keyword(s):  
Activation Energy ◽  
Couple Stress ◽  
Fluid Model ◽  
Flow Characteristics ◽  
Periodic Oscillation ◽  
Buongiorno’S Model ◽  
Nanoparticles Concentration ◽  
Flow Domain ◽  
Gyrotactic Microorganism ◽  
Accelerated Flow

AbstractOn the account of significance of bioconvection in biotechnology and several biological systems, valuable contributions have been performed by scientists in current decade. In current framework, a theoretical bioconvection model is constituted to examine the analyzed the thermally developed magnetized couple stress nanoparticles flow by involving narrative flow characteristics namely activation energy, chemical reaction and radiation features. The accelerated flow is organized on the periodically porous stretched configuration. The heat performances are evaluated via famous Buongiorno’s model which successfully reflects the important features of thermophoretic and Brownian motion. The composed fluid model is based on the governing equations of momentum, energy, nanoparticles concentration and motile microorganisms. The dimensionless problem has been solved analytically via homotopic procedure where the convergence of results is carefully examined. The interesting graphical description for the distribution of velocity, heat transfer of nanoparticles, concentration pattern and gyrotactic microorganism significance are presented with relevant physical significance. The variation in wall shear stress is also graphically underlined which shows an interesting periodic oscillation near the flow domain. The numerical interpretation for examining the heat mass and motile density transfer rate is presented in tubular form.

scholarly journals Insights into the Generalized Fourier's and Fick's Laws for Simulating Mixed Bioconvective Flows of Radiative-Reactive Walters-B Fluids Conveying Tiny Particles subject to Lorentz Force

2021 ◽  
Author(s):  
A. Wakif ◽  
I. L. Animasaun ◽  
Umair Khan ◽  
Ahmed Mohammed Alshehri
Keyword(s):  
Activation Energy ◽  
Differential Equations ◽  
Computational Cost ◽  
Energy Parameter ◽  
Linearization Method ◽  
Surface Drag ◽  
Force Coefficient ◽  
Buongiorno’S Model ◽  
Similarity Transformations ◽  
Nanoparticles Concentration

Abstract The current improvement in nanoscience and nanotechnology areas has attracted researchers' attention to biofuel, bioengineering, and biomedical and mechanical engineering applications. However, there is no report on the extension of Buongiorno's model incorporating the Cattaneo-Christov theory and the generalized Fick's law to reflect the significant impacts of Brownian motion, thermophoresis diffusion, thermal radiation, and activation energy. The governing partial differential equations (PDEs) suitable to model the case as mentioned above were converted into a unified set of ordinary differential equations (ODEs) by applying appropriate similarity transformations and solved numerically by using the Spectral Local Linearization Method (SLLM) and MATLAB in-built package. The SLLM numerical method provides robustness results with a higher level of exactness and low‐computational cost. It is worthy to conclude that the nanoparticles concentration distribution can be heightened considerably either by diminishing the Prandtl number and concentration relaxation parameter or increasing the values of nanoparticles concentration Biot number and activation energy parameter. An attractive reduction in the surface drag force coefficient is achievable via the intensifying values of the non-Newtonian parameter.

Bioconvection in the Rheology of Magnetized Couple Stress Nanofluid Featuring Activation Energy and Wu’s Slip

2020 ◽  
Vol 45 (1) ◽  
pp. 81-95 ◽  
Author(s):  
Sami Ullah Khan ◽  
H. Waqas ◽  
M. M. Bhatti ◽  
M. Imran
Keyword(s):  
Activation Energy ◽  
Thermal Radiation ◽  
Couple Stress ◽  
Radiation Effects ◽  
Numerical Solutions ◽  
Fluid Model ◽  
Velocity Slip ◽  
Animal Blood ◽  
Chain Molecules ◽  
Buongiorno Model

AbstractIn order to meet the current challenges in the fabrication of nanobiomaterials and enhancement of thermal extrusion systems, current theoretical continuation is targeted at the rheology of couple stress nanofluid by exploiting activation energy, porous media, thermal radiation, gyrotactic micro-organisms, and convective Nield boundary conditions. The heat and mass performances of nanofluid are captured with an evaluation of the famous Buongiorno model, which enables us to determine the attractive features of Brownian motion and thermophoretic diffusion. The couple stress fluid is beneficial to examine multiple kinds of physical problems because this fluid model has the capability to describe the rheology of various complex fluids, e. g., fluids having long-chain molecules as a polymeric suspension, liquid crystals, lubricants, and human and animal blood. Simultaneous behavior of the magnetic field and porosity are studied with thermal radiation effects. The distribution of velocity has been conducted by using second-order velocity slip (Wu’s slip) and activation energy features. For the dimensionless purpose, the similarity variable has been initiated, and the modeled equations are renovated sufficiently. A famous shooting method is used to determine the numerical solutions, and accurate results have been obtained. A variety of critical flow parameters is graphically illustrated with physical significance.

Energy-minimization multiscale based mesoscale modeling and applications in gas-fluidized catalytic reactors

2019 ◽  
Vol 35 (8) ◽  
pp. 879-915 ◽  
Author(s):  
Bona Lu ◽  
Yan Niu ◽  
Feiguo Chen ◽  
Nouman Ahmad ◽  
Wei Wang ◽  
...  
Keyword(s):  
Energy Minimization ◽  
Fluid Model ◽  
Scale Up ◽  
Flow Characteristics ◽  
Chemical Kinetic ◽  
Mesoscale Modeling ◽  
Catalytic Reactors ◽  
Chemical Kinetic Model ◽  
Starting Point ◽  
Wide Range

Abstract Gas-solid fluidization is intrinsically dynamic and manifests mesoscale structures spanning a wide range of length and timescales. When involved with reactions, more complex phenomena emerge and thus pose bigger challenges for modeling. As the mesoscale is critical to understand multiphase reactive flows, which the conventional two-fluid model without mesoscale modeling may be inadequate to resolve even using extremely fine grids, this review attempts to demonstrate that the energy-minimization multiscale (EMMS) model could be a starting point to develop such mesoscale modeling. Then, the EMMS-based mesoscale modeling with emphasis on formulation of drag coefficients for different fluidization regimes, modification of mass transfer coefficient, and other extensions are discussed in an attempt to resolve the emerging challenges. Its applications with examples of development of novel fluid catalytic cracking and methanol-to-olefins processes prove that the mesoscale modeling plays a remarkable role in improving the predictions in hydrodynamic behaviors and overall reaction rate. However, the product content primarily depends on the chemical kinetic model itself, suggesting the necessity of an effective coupling between chemical kinetics and flow characteristics. The mesoscale modeling can be believed to accelerate the traditional experimental-based scale-up process with much lower cost in the future.

A higher order slip flow of generalized Micropolar nanofluid with applications of motile microorganisms, nonlinear thermal radiation and activation energy

2021 ◽  
pp. 2150095
Author(s):  
Usman ◽  
M. Ijaz Khan ◽  
Sami Ullah Khan ◽  
Abuzar Ghaffari ◽  
Yu-Ming Chu ◽  
...  
Keyword(s):  
Activation Energy ◽  
Thermal Radiation ◽  
Micropolar Fluid ◽  
Fluid Model ◽  
Slip Flow ◽  
Higher Order ◽  
Nonlinear Thermal Radiation ◽  
Coupled Equations ◽  
Flow Parameters ◽  
Micropolar Nanofluid

This communication aims to develop the thermal flow model for generalized micropolar nanofluid with insensitive applications of bioconvection, activation energy and nonlinear thermal radiation. The generalized micropolar fluid model is the extension of traditional micropolar fluid model with viscoelastic relations. The viscous nature of non-Newtonian micropolar material can be successfully predicted with help of this model. The motivating idea for considering the motile microorganisms is to control the nanoparticles suspension effectively. The higher order slip relations are incorporated to examine the bio-convective phenomenon. The simplified coupled equations in terms of non-dimensional variables are numerically treated with shooting scheme. The reliable graphical outcomes are presented for flow parameters governed to the transported problem. The flow pattern of each parameter is highlighted in view of viscous nature of micropolar fluid.

scholarly journals Numerical Solution of Non-Newtonian Fluid Flow Due to Rotatory Rigid Disk

Symmetry ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 699 ◽  
Author(s):  
Khalil Ur Rehman ◽  
M. Y. Malik ◽  
Waqar A Khan ◽  
Ilyas Khan ◽  
S. O. Alharbi
Keyword(s):  
Brownian Motion ◽  
Newtonian Fluid ◽  
Fluid Model ◽  
Rotating Disk ◽  
Casson Fluid ◽  
Infinite Domain ◽  
Nanoparticles Concentration ◽  
Navier’S Slip ◽  
Local Sherwood Number

In this article, the non-Newtonian fluid model named Casson fluid is considered. The semi-infinite domain of disk is fitted out with magnetized Casson liquid. The role of both thermophoresis and Brownian motion is inspected by considering nanosized particles in a Casson liquid spaced above the rotating disk. The magnetized flow field is framed with Navier’s slip assumption. The Von Karman scheme is adopted to transform flow narrating equations in terms of reduced system. For better depiction a self-coded computational algorithm is executed rather than to move-on with build-in array. Numerical observations via magnetic, Lewis numbers, Casson, slip, Brownian motion, and thermophoresis parameters subject to radial, tangential velocities, temperature, and nanoparticles concentration are reported. The validation of numerical method being used is given through comparison with existing work. Comparative values of local Nusselt number and local Sherwood number are provided for involved flow controlling parameters.

Numerical Study of MHD Viscoelastic Fluid Flow with Binary Chemical Reaction and Arrhenius Activation Energy

2017 ◽  
Vol 15 (1) ◽  
Author(s):  
M. Mustafa ◽  
A. Mushtaq ◽  
T. Hayat ◽  
A. Alsaedi
Keyword(s):  
Activation Energy ◽  
Fluid Flow ◽  
Chemical Reaction ◽  
Viscoelastic Fluid ◽  
Numerical Study ◽  
Fluid Model ◽  
Constitutive Relations ◽  
Mathematical Formulation ◽  
Large Temperature ◽  
Temperature Function

Abstract Here we address the influence of heat/mass transfer on MHD axisymmetric viscoelastic fluid flow developed by an elastic sheet stretching linearly in the radial direction. Constitutive relations of Maxwell fluid model are utilized in mathematical formulation of the problem. Non-linear radiation heat flux is factored in the model which accounts for both small and large temperature differences. Chemical reaction effects with modified Arrhenius energy function are analyzed which are not yet explored for viscoelastic fluid flows. Highly accurate numerical computations are performed. Our computations show S-shaped profiles of temperature function in case of sufficiently large temperature differences. Species concentration increases when activation energy for chemical reaction is increased. However, both chemical reaction rate and temperature gradient tend to reduce the solute concentration.

scholarly journals SWIMMING DYNAMICS OF A MICRO-ORGANISM IN A COUPLE STRESS FLUID: A RHEOLOGICAL MODEL OF EMBRYOLOGICAL HYDRODYNAMIC PROPULSION

2017 ◽  
Vol 17 (03) ◽  
pp. 1750054 ◽  
Author(s):  
N. ALI ◽  
M. SAJID ◽  
Z. ABBAS ◽  
O. ANWAR BÉG
Keyword(s):  
Swimming Speed ◽  
Couple Stress ◽  
Fluid Model ◽  
Lateral Displacement ◽  
Structural Characteristics ◽  
Couple Stress Fluid ◽  
Fluid Medium ◽  
Fluid Parameter ◽  
Work Done ◽  
Perturbation Solutions

Mathematical simulations of embryological fluid dynamics are fundamental to improving clinical understanding of the intricate mechanisms underlying sperm locomotion. The strongly rheological nature of reproductive fluids has been established for a number of decades. Complimentary to clinical studies, mathematical models of reproductive hydrodynamics provide a deeper understanding of the intricate mechanisms involved in spermatozoa locomotion which can be of immense benefit in clarifying fertilization processes. Although numerous non-Newtonian studies of spermatozoa swimming dynamics in non-Newtonian media have been communicated, very few have addressed the micro-structural characteristics of embryological media. This family of micro-continuum models include Eringen’s micro-stretch theory, Eringen’s microfluid and micropolar constructs and V. K. Stokes’ couple stress fluid model, all developed in the 1960s. In the present paper we implement the last of these models to examine the problem of micro-organism (spermatozoa) swimming at low Reynolds number in a homogenous embryological fluid medium with couple stress effects. The micro-organism is modeled as with Taylor’s classical approach, as an infinite flexible sheet on whose surface waves of lateral displacement are propagated. The swimming speed of the sheet and rate of work done by it are determined as function of the parameters of orbit and the couple stress fluid parameter ([Formula: see text]). The perturbation solutions are validated with a Nakamura finite difference algorithm. The perturbation solutions reveal that the normal beat pattern is effective for both couple stress and Newtonian fluids only when the amplitude of stretching wave is small. The swimming speed is observed to decrease with couple stress fluid parameter tending to its Newtonian limit as alpha tends to infinity. However the rate of work done by the sheet decreases with [Formula: see text] and approaches asymptotically to its Newtonian value. The present solutions also provide a good benchmark for more advanced numerical simulations of micro-organism swimming in couple-stress rheological biofluids.

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