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Anwar O Beg - One of the best experts on this subject based on the ideXlab platform.
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unsteady electroMagnetic radiative nanofluid stagnation point flow from a stretching sheet with chemically reactive nanoparticles stefan blowing effect and entropy generation
Proceedings of the Institution of Mechanical Engineers Part N: Journal of Nanomaterials Nanoengineering and Nanosystems, 2018Co-Authors: Puneet Rana, A Kadir, Nisha Shukla, Anwar O Beg, Bani SinghAbstract:The present article investigates the combined influence of nonlinear radiation, Stefan blowing and chemical reactions on unsteady EMHD stagnation point flow of a nanofluid from a horizontal stretching sheet. Both electrical and Magnetic Body forces are considered. In addition, the effects of velocity slip, thermal slip and mass slip are considered at the boundaries. An analytical method named as homotopy analysis method is applied to solve the non-dimensional system of nonlinear partial differential equations which are obtained by applying similarity transformations on governing equations. The effects of emerging parameters including Stefan blowing parameter, electric parameter, Magnetic parameter etc. on the important physical quantities are presented graphically. Additionally, an entropy generation analysis is provided in this article for thermal optimization. The flow is observed to be accelerated both with increasing Magnetic field and electrical field. Entropy generation number is markedly enhanced with greater Magnetic field, electrical field and Reynolds number, whereas it is reduced with increasing chemical reaction parameter.
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electro magneto hydrodynamic peristaltic pumping of couple stress biofluids through a complex wavy micro channel
Journal of Molecular Liquids, 2017Co-Authors: Dharmendra Tripathi, Anwar O Beg, Ravinder Jhorar, A KadirAbstract:Abstract Biomimetic propulsion mechanisms are increasingly being explored in engineering sciences. Peristalsis is one of the most efficient of these mechanisms and offers considerable promise in microscale fluidics. Electrokinetic peristalsis has recently also stimulated significant attention. Electrical and Magnetic fields also offer an excellent mode for regulating flows. Motivated by novel applications in electro-conductive microchannel transport systems, the current article investigates analytically the electroMagnetic pumping of non-Newtonian aqueous electrolytes via peristaltic waves in a two-dimensional microchannel with different peristaltic waves propagating at the upper and lower channel wall (complex wavy scenario). The Stokes couple stress model is deployed to capture micro-structural characteristics of real working fluids. The unsteady two-dimensional conservation equations for mass and momentum conservation, electro-kinetic and Magnetic Body forces, are formulated in two dimensional Cartesian co-ordinates. The transport equations are transformed from the wave frame to the laboratory frame and the electrical field terms rendered into electrical potential terms via the Poisson-Boltzmann equation, Debye length approximation and ionic Nernst Planck equation. The dimensionless emerging linearized electro-Magnetic boundary value problem is solved using integral methods. The influence of Helmholtz-Smoluchowski velocity (characteristic electro-osmotic velocity), couple stress length parameter (measure of the polarity of the fluid), Hartmann Magnetic number, and electro-osmotic parameter on axial velocity, volumetric flow rate, time-averaged flow rate and streamline distribution are visualized and interpreted at length.
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magnetohydrodynamic free convection boundary layer flow of non newtonian tangent hyperbolic fluid from a vertical permeable cone with variable surface temperature
Journal of The Brazilian Society of Mechanical Sciences and Engineering, 2017Co-Authors: Abdul S Gaffar, Ramachandra V Prasad, Keshava S Reddy, Anwar O BegAbstract:The nonlinear, non-isothermal steady-state boundary layer flow and heat transfer of an incompressible tangent hyperbolic non-Newtonian (viscoelastic) fluid from a vertical permeable cone with Magnetic field are studied. The transformed conservation equations are solved numerically subject to physically appropriate boundary conditions using the second-order accurate implicit finite difference Keller-box technique. The numerical code is validated with previous studies. The influence of a number of emerging non-dimensional parameters, namely a Weissenberg number (We), rheological power law index (m), surface temperature exponent (n), Prandtl number (Pr), Magnetic parameter (M) suction/injection parameter (fw) and dimensionless tangential coordinate (ξ) on velocity and temperature evolution in the boundary layer regime, is examined in detail. Furthermore, the effects of these parameters on surface heat transfer rate and local skin friction are also investigated. It is observed that velocity, surface heat transfer rate and local skin friction are reduced with increasing Weissenberg number, but temperature is increased. Increasing m enhances velocity and surface heat transfer rate but reduces temperature and local skin friction. An increase in non-isothermal power law index (n) is observed to decrease the velocity and temperature. Increasing Magnetic parameter (M) is found to decrease the velocity and increase the temperature. Overall, the primary influence on free convection is sustained through the Magnetic Body force parameter, M, and also the surface mass flux (injection/suction) parameter, fw. The rheological effects, while still prominent, are not as dramatic. Boundary layers (both hydrodynamic and thermal) are, therefore, most strongly modified by the applied Magnetic field and wall mass flux effect. The study is pertinent to smart coatings, e.g., durable paints, aerosol deposition processing and water-based solvent thermal treatment in chemical engineering.
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a numerical study of magnetohydrodynamic transport of nanofluids over a vertical stretching sheet with exponential temperature dependent viscosity and buoyancy effects
Chemical Physics Letters, 2016Co-Authors: Noreen Sher Akbar, Dharmendra Tripathi, Z H Khan, Anwar O BegAbstract:Abstract In this paper, a mathematical study is conducted of steady incompressible flow of a temperature-dependent viscous nanofluid from a vertical stretching sheet under applied external Magnetic field and gravitational Body force effects. The Reynolds exponential viscosity model is deployed. Electrically-conducting nanofluids are considered which comprise a suspension of uniform dimension nanoparticles suspended in viscous base fluid. The nanofluid sheet is extended with a linear velocity in the axial direction. The Buonjiornio model is utilized which features Brownian motion and thermophoresis effects. The partial differential equations for mass, momentum, energy and species (nano-particle concentration) are formulated with Magnetic Body force term. Viscous and Joule dissipation effects are neglected. The emerging nonlinear, coupled, boundary value problem is solved numerically using the Runge–Kutta fourth order method along with a shooting technique. Graphical solutions for velocity, temperature, concentration field, skin friction and Nusselt number are presented. Furthermore stream function plots are also included. Validation with Nakamura’s finite difference algorithm is included. Increasing nanofluid viscosity is observed to enhance temperatures and concentrations but to reduce velocity magnitudes. Nusselt number is enhanced with both thermal and species Grashof numbers whereas it is reduced with increasing thermophoresis parameter and Schmidt number. The model is applicable in nano-material manufacturing processes involving extruding sheets.
Bradley J. Nelson - One of the best experts on this subject based on the ideXlab platform.
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In Vitro Oxygen Sensing Using Intraocular Microrobots
IEEE Transactions on Biomedical Engineering, 2012Co-Authors: Olgaç Ergeneman, George Chatzipirpiridis, Juho Pokki, Marta Marin-suárez, Georgios A. Sotiriou, Santiago Medina-rodriguez, Jorge Fernández F. Sanchez, Alberto Fernandez-gutiérrez, Salvador Pane, Bradley J. NelsonAbstract:We present a luminescence oxygen sensor integrated with a wireless intraocular microrobot for minimally-invasive diagnosis. This microrobot can be accurately controlled in the intraocular cavity by applying Magnetic fields. The microrobot consists of a Magnetic Body susceptible to Magnetic fields and a sensor coating. This coating embodies Pt(II) octaethylporphine (PtOEP) dyes as the luminescence material and polystyrene as a supporting matrix, and it can be wirelessly excited and read out by optical means. The sensor works based on quenching of luminescence in the presence of oxygen. The excitation and emission spectrum, response time, and oxygen sensitivity of the sensor were characterized using a spectrometer. A custom device was designed and built to use this sensor for intraocular measurements with the microrobot. Due to the intrinsic nature of luminescence lifetimes, a frequency-domain lifetime measurement approach was used. An alternative sensor design with increased performance was demonstrated by using poly(styrene-co-maleic anhydride) (PS-MA) and PtOEP nanospheres.
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modeling Magnetic torque and force for controlled manipulation of soft Magnetic bodies
IEEE Transactions on Robotics, 2007Co-Authors: Jake J. Abbott, Michael P. Kummer, Olgaç Ergeneman, Ann M. Hirt, Bradley J. NelsonAbstract:We calculate the torque and force generated by an arbitrary Magnetic field on an axially symmetric soft-Magnetic Body. We consider the magnetization of the Body as a function of the applied field, using a continuous model that unifies two disparate Magnetic models. The continuous torque and force follow. The model is verified experimentally, and captures the often neglected region between weak and saturating fields, where interesting behavior is observed. We provide the field direction to maximize torque for a given field magnitude. We also find an absolute maximum torque, for a given Body geometry and material, which can be generated with relatively weak applied fields. This paper is aimed at those interested in systems-level analysis, simulation, and real-time control of soft-Magnetic bodies.
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Modeling Magnetic torque and force for controlled manipulation of soft-Magnetic bodies
IEEE Transactions on Robotics, 2007Co-Authors: Jake J. Abbott, Michael P. Kummer, Olgaç Ergeneman, Ann M. Hirt, Bradley J. NelsonAbstract:We calculate the torque and force generated by an arbitrary Magnetic field on an axially symmetric soft-Magnetic Body. We consider the magnetization of the Body as a function of the applied field, using a continuous model that unifies two disparate Magnetic models. The continuous torque and force follow. The model is verified experimentally, and captures the often-neglected region between weak and saturating fields, where interesting behavior is observed. We provide the optimal field direction for a given field magnitude. We find a maximum possible torque, which can be generated with relatively weak applied fields. This paper facilitates systems-level analysis, simulation, and real-time control of soft-Magnetic bodies.
Oa Beg - One of the best experts on this subject based on the ideXlab platform.
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Unsteady squeezing flow of a magnetized nano-lubricant between parallel disks with Robin boundary conditions
'SAGE Publications', 2021Co-Authors: Jc Umavathi, Sl Patil, Mahanthesh B, Oa BegAbstract:The aim of the present work is to examine the impact of magnetized nanoparticles (NPs) in enhancement of heat transport in a tribological system subjected to convective type heating (Robin) boundary conditions. The regime examined comprises the squeezing transition of a Magnetic (smart) Newtonian nanolubricant between two analogous disks under an axial magnetism. The lower disk is permeable whereas the upper disk is solid. The mechanisms of haphazard motion of NPs and thermophoresis are simulated. The non-dimensional problem is solved numerically using a finite difference method in the MATLAB bvp4c solver based on Lobotto quadrature, to scrutinize the significance of thermophoresis parameter, squeezing number, Hartmann number, Prandtl number and Brownian motion parameter on velocity, temperature, nanoparticle concentration, Nusselt number, factor of friction and Sherwood number distributions. The obtained results for the friction factor are validated against previously published results. It is found that friction factor at the disk increases with intensity in applied Magnetic field. The haphazard (Brownian) motion of nanoparticles causes an enhancement in thermal field. Suction and injection are found to induce different effects on transport characteristics depending on the specification of equal or unequal Biot numbers at the disks. The main quantitative outcome is that, unequal Biot numbers produce significant cooling of the regime for both cases of disk suction or injection, indicating that Robin boundary conditions yield substantial deviation from conventional thermal boundary conditions. Higher thermophoretic parameter also elevates temperatures in the regime. The nanoparticles concentration at the disk is boosted with higher values of Brownian motion parameter. The response of temperature is similar in both suction and injection cases; however, this tendency is quite opposite for nanoparticle concentrations. In the core zone, the resistive Magnetic Body force dominates and this manifests in a significant reduction in velocity i.e. damping. The heat buildup in squeeze films (which can lead to corrosion and degradation of surfaces) can be successfully removed with Magnetic nanoparticles leading to prolonged serviceability of lubrication systems and the need for less maintenance
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Nonlinear nanofluid fluid flow under the consequences of Lorentz forces and Arrhenius kinetics through a permeable surface : a robust spectral approach
'Elsevier BV', 2021Co-Authors: Zhang L, M M Bhatti, Oa Beg, Shahid A, Ellahi R, Sa SaitAbstract:Background: Emerging applications in nanomaterials processing are increasingly featuring multiple physical phenomena including Magnetic Body forces, chemical reactions and high temperature behavior. Stimulated by developing a deeper insight of nanoscale fluid dynamics in such manufacturing systems, in the current article, we study the Magnetic nanofluid dynamics along a nonlinear porous stretching sheet with Arrhenius chemical kinetics and wall transpiration. Appropriate similarity transformations are employed to simplify the governing flow problem. Methods: The emerging momentum, thermal energy and nanoparticle concentration ordinary differential conservation equations are solved numerically with a hybrid technique combining Successive Linearization and Chebyshev Spectral Collocation. A parametric study of the impacts of Magnetic parameter, porous media parameter, Brownian motion parameter, parameters for thermophoresis, radiation, Arrhenius function, suction/injection (transpiration) and nonlinear stretching in addition to Schmidt number on velocity, temperature and nanoparticle (concentration) distribution is conducted. A detail numerical comparison is presented with different numerical and 2 analytical techniques as a specific case of the current investigation. Findings: Increasing chemical reaction constant parameter significantly decreases nanoparticle concentration magnitudes and results in a thickening of the nanoparticle concentration boundary layer. Enhancing the values of activation energy parameter significantly increases the nanoparticle concentration magnitudes. Increasing thermophoresis parameter elevates both temperature and nanoparticle concentration. Increasing radiation parameter increases temperature and thermal boundary layer thickness. Enlarging Brownian motion parameter (smaller nanoparticles) and Schmidt number both depress the nanoparticle concentration
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Non-similar radiative bioconvection nanofluid flow under oblique Magnetic field with entropy generation
'Geophysical Center of the Russian Academy of Sciences', 2021Co-Authors: Shukla N, Rana P, Kuharat S, Oa BegAbstract:Motivated by exploring the near-wall transport phenomena involved in bioconvection fuel cells combined with electrically conducting nanofluids, in the present article, a detailed analytical treatment using homotopy analysis method (HAM) is presented of non-similar bioconvection flow of a nanofluid under the influence of Magnetic field (Lorentz force) and gyrotactic microorganisms. The flow is induced by a stretching sheet under the action of a oblique Magnetic field. In addition, nonlinear radiation effects are considered which are representative of solar flux in green fuel cells. A second thermodynamic law analysis has also been carried out for the present study to examine entropy generation (irreversibility) minimization. The influence of Magnetic parameter, radiation parameter and bioconvection Rayleigh number on skin friction coefficient, Nusselt number, micro-organism flux and entropy generation number (EGN) is visualized graphically with detailed interpretation. Validation of the HAM solutions with published results is also included for the non-Magnetic case in the absence of bioconvection and nanofluid effects. The computations show that the flow is decelerated with increasing Magnetic Body force parameter and bioconvection Rayleigh number whereas it is accelerated with stronger radiation parameter. EGN is boosted with increasing Reynolds number, radiation parameter and Prandtl number whereas it is reduced with increasing inclination of Magnetic field
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Spectral computation of reactive bi-directional hydroMagnetic non-Newtonian convection flow from a stretching upper parabolic surface in non-Darcy porous medium
'World Scientific Pub Co Pte Lt', 2021Co-Authors: Shahid A, M M Bhatti, Oa Beg, Il Animasaun, Javid KAbstract:The current article presents a mathematical model for bi-directional convection magnetohydrodynamic (MHD) tangent hyperbolic nanofluid flow from the upper horizontal subsurface of a stretching parabolic surface to a non-Darcian porous medium, as a simulation of nano-coating. Chemical reaction, activation energy and thermosolutal buoyancy effects are included. The Darcy-Brinkman-Forchheimer model is deployed which permits the analysis of inertial (second order) porous drag effects. The Buongiorno nanoscale model is deployed which includes Brownian motion and thermophoresis effects. The dimensionless, transformed, nonlinear, coupled ordinary differential equations are solved by implementing the spectral relaxation method (SRM). Validation with previous studies is included. The numerical influence of key parameters on transport characteristics is evaluated and visualized graphically. Velocity is elevated (and momentum boundary layer thickness is reduced) with increasing wall thickness parameter, permeability parameter, Forchheimer parameter, Weissenberg (rheological) parameter and modified Hartmann (Magnetic Body force) number. Velocity enhancement is also computed with increment in stretching rate parameter, rheological power-law index, thermal Grashof number, and species (solutal) Grashof number, and momentum boundary layer thickness diminishes. Temperature is suppressed with increasing stretching rate index and Prandtl number whereas it is substantially elevated with increasing Brownian motion and thermophoresis parameters. Velocity and temperature profiles are reduced adjacent to the parabolic surface with larger wall thickness parameter for stretching rate index < 1, whereas the reverse behaviour is observed for stretching rate index>1. Nano-particle concentration magnitude is depleted with larger numeric of Lewis number and the Brownian motion parameter, whereas it is enhanced with greater values of the stretching index and thermophoresis parameter. The nanoparticle concentration magnitude is reduced with an increase in chemical reaction rate parameter whereas it is boosted with activation energy parameter. Skin friction, Nusselt number and Sherwood number are also computed. The study is relevant to electroMagnetic nano-materials coating processes with complex chemical reactions
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Computation of transient radiative reactive thermo-solutal magnetohydrodynamic convection in inclined mhd hall generator flow with dissipation and cross diffusion
'Begell House', 2020Co-Authors: Oa Beg, Modugula P, Kadir AAbstract:The present article investigates the collective influence of chemical reaction, viscous dissipation and Hall current Magnetic effects on timedependent radiative magnetohydrodynamic flow, heat and mass transfer from an inclined wall embedded in a homogenous, isotropic highpermeability porous medium. The model developed is relevant to near wall magnetohydrodynamic energy generator transport phenomena in which chemical corrosion effects may arise during operations. The governing non-linear partial differential equations for mass, momentum, energy and species conservation are transformed into a system of coupled non-linear dimensionless partial differential equations with appropriate similarity variables. The normalized conservation equations are then solved with a robust finite element method (MATLABFEM) subject to corresponding initial and boundary conditions. Important dimensionless parameters emerging are Eckert number, thermal Grashof number, solutal Grashof number, Magnetic Body force parameter, Hall parameter, permeability parameter, Dufour number, Soret number, time, radiation-conduction parameter, chemical reaction parameter, heat absorption parameter, Prandtl number, Schmidt number and wall angle. Primary velocity is enhanced with Eckert number, thermal Grashof number, solutal Grashof number, Hall parameter, permeability parameter, Dufour number, Soret number, radiation-conduction parameter and time whereas it is reduced with first order chemical reaction parameter, heat absorption, Magnetic Body force parameter, Prandtl number, Schmidt number and wall inclination. Secondary velocity is elevated with Eckert number, solutal Grashof number, thermal Grashof number, Magnetic Body force parameter, Hall parameter, radiation-conduction parameter, Dufour number, Soret number and time whereas it is suppressed with reaction parameter, heat absorption, Prandtl number, Schmidt number and wall inclination. Temperature is enhanced with Eckert number, Dufour number, heat absorption, radiation-conduction parameter and time whereas it is depressed with Prandtl number. Species concentration is reduced with increasing chemical reaction parameter (destructive homogenous reaction) and Schmidt number whereas it is elevated with Soret number and time. Extensive discussion of the finite element formulation, convergence and validation is provided Skin friction, Nusselt number and Sherwood number distributions are also provided for selected parameter variation. Validation of solutions with published literature is also included for several special cases, namely non-reactive, non-dissipative flow in the absence of heat generation or absorption. Further validation is included using a multi-step differential transform method (MS-DTM). The present simulations provide an interesting insight into complex fluid/thermal/species diffusion characteristics in the boundary layer region of relevance to working MHD generator systems
Dharmendra Tripathi - One of the best experts on this subject based on the ideXlab platform.
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Peristaltic pumping of Magnetic nanofluids with thermal radiation and temperature-dependent viscosity effects: Modelling a solar magneto-biomimetic nanopump
Renewable Energy, 2019Co-Authors: J Prakash, E. P. Siva, Dharmendra Tripathi, S KuharatAbstract:Abstract Nanofluids have shown significant promise in the thermal enhancement of many industrial systems. They have been developed extensively in energy applications in recent years. Solar energy systems are one of the most promising renewables available to humanity and these are increasingly being re-designed to benefit from nanofluids. Most designs of solar collectors involve fixed (rigid) geometries which may be cylindrical, parabolic, tubular or flat-plate types. Modern developments in biomimetics have identified that deformable conduit structures may be beneficial for sustainable energy systems. Motivated by these aspects, in the current work we present a novel model for simulating a biomimetic peristaltic solar magnetohydrodynamic nanofluid-based pump. The working fluid is a magnetized nanofluid which comprises a base fluid containing suspended Magnetic nano-particles. The novelty of the present work is the amalgamation of biomimetics (peristaltic propulsion), magnetohydrodynamics and nanofluid dynamics to produce a hybrid solar pump system model. Heat is transferred via distensibility of the conduit in the form of peristaltic thermal waves and buoyancy effects. An externally applied Magnetic field achieves the necessary circuit design for generating Lorentzian Magnetic Body force in the fluid. A variable viscosity modification of the Buongiorno nanofluid model is employed which features thermophoretic Body force and Brownian dynamic effects. To simulate solar loading conditions a thermal radiative flux model is also deployed. An asymmetric porous channel is investigated with multiple amplitudes and phases for the wall wavy motion. The channel also contains a homogenous, isotropic porous medium which is simulated with a modified Darcy model. Heat generation/absorption effects are also examined. The electrically-conducting nature of the nanofluid invokes magnetohydrodynamic effects. The moving boundary value problem is normalized and linearized using the lubrication approach. Analytical solutions are derived for axial velocity, temperature and nanoparticle volume fraction. Validation is conducted with Maple numerical quadrature. Furthermore, the salient features of pumping and trapping phenomena discourse briefly. The observations demonstrate promising features of the solar magnetohydrodynamic peristaltic nanofluid pump which may also be exploited in spacecraft applications, biological smart drug delivery etc.
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electro magneto hydrodynamic peristaltic pumping of couple stress biofluids through a complex wavy micro channel
Journal of Molecular Liquids, 2017Co-Authors: Dharmendra Tripathi, Anwar O Beg, Ravinder Jhorar, A KadirAbstract:Abstract Biomimetic propulsion mechanisms are increasingly being explored in engineering sciences. Peristalsis is one of the most efficient of these mechanisms and offers considerable promise in microscale fluidics. Electrokinetic peristalsis has recently also stimulated significant attention. Electrical and Magnetic fields also offer an excellent mode for regulating flows. Motivated by novel applications in electro-conductive microchannel transport systems, the current article investigates analytically the electroMagnetic pumping of non-Newtonian aqueous electrolytes via peristaltic waves in a two-dimensional microchannel with different peristaltic waves propagating at the upper and lower channel wall (complex wavy scenario). The Stokes couple stress model is deployed to capture micro-structural characteristics of real working fluids. The unsteady two-dimensional conservation equations for mass and momentum conservation, electro-kinetic and Magnetic Body forces, are formulated in two dimensional Cartesian co-ordinates. The transport equations are transformed from the wave frame to the laboratory frame and the electrical field terms rendered into electrical potential terms via the Poisson-Boltzmann equation, Debye length approximation and ionic Nernst Planck equation. The dimensionless emerging linearized electro-Magnetic boundary value problem is solved using integral methods. The influence of Helmholtz-Smoluchowski velocity (characteristic electro-osmotic velocity), couple stress length parameter (measure of the polarity of the fluid), Hartmann Magnetic number, and electro-osmotic parameter on axial velocity, volumetric flow rate, time-averaged flow rate and streamline distribution are visualized and interpreted at length.
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a numerical study of magnetohydrodynamic transport of nanofluids over a vertical stretching sheet with exponential temperature dependent viscosity and buoyancy effects
Chemical Physics Letters, 2016Co-Authors: Noreen Sher Akbar, Dharmendra Tripathi, Z H Khan, Anwar O BegAbstract:Abstract In this paper, a mathematical study is conducted of steady incompressible flow of a temperature-dependent viscous nanofluid from a vertical stretching sheet under applied external Magnetic field and gravitational Body force effects. The Reynolds exponential viscosity model is deployed. Electrically-conducting nanofluids are considered which comprise a suspension of uniform dimension nanoparticles suspended in viscous base fluid. The nanofluid sheet is extended with a linear velocity in the axial direction. The Buonjiornio model is utilized which features Brownian motion and thermophoresis effects. The partial differential equations for mass, momentum, energy and species (nano-particle concentration) are formulated with Magnetic Body force term. Viscous and Joule dissipation effects are neglected. The emerging nonlinear, coupled, boundary value problem is solved numerically using the Runge–Kutta fourth order method along with a shooting technique. Graphical solutions for velocity, temperature, concentration field, skin friction and Nusselt number are presented. Furthermore stream function plots are also included. Validation with Nakamura’s finite difference algorithm is included. Increasing nanofluid viscosity is observed to enhance temperatures and concentrations but to reduce velocity magnitudes. Nusselt number is enhanced with both thermal and species Grashof numbers whereas it is reduced with increasing thermophoresis parameter and Schmidt number. The model is applicable in nano-material manufacturing processes involving extruding sheets.
A Kadir - One of the best experts on this subject based on the ideXlab platform.
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modeling Magnetic nanopolymer flow with induction and nano particle solid volume fraction effects solar Magnetic nano polymer fabrication simulation
Proceedings of the Institution of Mechanical Engineers Part N: Journal of Nanomaterials Nanoengineering and Nanosystems, 2019Co-Authors: S Kuharat, A Kadir, M Ferdows, Md ShamshuddinAbstract:A mathematical model is presented for the nonlinear steady, forced convection, hydroMagnetic flow of electro-conductive Magnetic nano-polymer with Magnetic induction effects included. The transformed two-parameter, non-dimensional governing partial differential equations for mass, momentum, Magnetic induction and heat conservation are solved with the local non-similarity method (LNM) subject to appropriate boundary conditions. Keller’s implicit finite difference “box” method (KBM) is used to validate solutions. Computations for four different nanoparticles and three different base fluids are included. Silver nanoparticles in combination with various base fluids enhance temperatures and induced Magnetic field and accelerate the flow. An elevation in Magnetic Body force number decelerates the flow whereas an increase in Magnetic Prandtl number elevates the Magnetic induction. Furthermore, increasing nanoparticle solid volume fraction is found to substantially boost temperatures. Applications of the study arise in advanced Magnetic solar nano-materials (fluids) processing technologies.
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second law analysis of flow in a circular pipe with uniform suction and Magnetic field effects
Journal of Heat Transfer-transactions of The Asme, 2019Co-Authors: G Nagaraju, Srinivas Jangili, J Ramana V Murthy, A KadirAbstract:The present paper investigates analytically the two-dimensional heat transfer and entropy generation characteristics of axi-symmetric, incompressible viscous fluid flow in a horizontal circular pipe.The flow is subjected to an externally applied uniform suction across the wall in normal direction and a constant radial Magnetic field. Constant wall temperature is considered as the thermal boundary condition.The reduced Navier-Stokes equations in a cylindrical coordinate system are solved to obtain the velocity and temperature distributions. The velocity distributions are expressed in terms of stream function and thesolution is obtained using the Homotopy Analysis Method (HAM). Validation with earlier non-Magnetic solutions in the literature is incorporated. The effects of various parameters on axial and radial velocities, temperature, axial and radial entropy generation numbers, and axial and radial Bejan numbers and are presented graphically and interpreted at length. Streamlines, isotherms, pressure, entropy generation number and Bejan number contours are also visualized. Increasing Magnetic Body force parameter shifts the peak of the velocity curve near to the axis where as it accelerates the radial flow. The study is relevant to thermodynamic optimization of Magnetic blood flows and electroMagnetic industrial flows featuring heat transfer.
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unsteady electroMagnetic radiative nanofluid stagnation point flow from a stretching sheet with chemically reactive nanoparticles stefan blowing effect and entropy generation
Proceedings of the Institution of Mechanical Engineers Part N: Journal of Nanomaterials Nanoengineering and Nanosystems, 2018Co-Authors: Puneet Rana, A Kadir, Nisha Shukla, Anwar O Beg, Bani SinghAbstract:The present article investigates the combined influence of nonlinear radiation, Stefan blowing and chemical reactions on unsteady EMHD stagnation point flow of a nanofluid from a horizontal stretching sheet. Both electrical and Magnetic Body forces are considered. In addition, the effects of velocity slip, thermal slip and mass slip are considered at the boundaries. An analytical method named as homotopy analysis method is applied to solve the non-dimensional system of nonlinear partial differential equations which are obtained by applying similarity transformations on governing equations. The effects of emerging parameters including Stefan blowing parameter, electric parameter, Magnetic parameter etc. on the important physical quantities are presented graphically. Additionally, an entropy generation analysis is provided in this article for thermal optimization. The flow is observed to be accelerated both with increasing Magnetic field and electrical field. Entropy generation number is markedly enhanced with greater Magnetic field, electrical field and Reynolds number, whereas it is reduced with increasing chemical reaction parameter.
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numerical exploration of thermal radiation and biot number effects on the flow of a non newtonian mhd williamson fluid over a vertical convective surface
Heat Transfer Research, 2018Co-Authors: Chota Hyder Amanulla, Oa Beg, N Nagendra, Annasagaram Subba Rao, A KadirAbstract:A theoretical and computational study of the magnetohydrodynamic flow and free convection heat transfer in an electroconductive polymer on the external surface of a vertical plate under radial Magnetic field is presented. The Biot number effects are considered at the vertical plate surface via modified boundary conditions. The Williamson viscoelastic model is employed which is representative of certain industrial polymers. The nondimensional, transformed boundary layer equations for momentum and energy are solved with the second-order accurate implicit Keller box finite difference method under appropriate boundary conditions. Validation of the numerical solutions is achieved via benchmarking with earlier published results. The influence of Weissenberg number (ratio of the relaxation time of the fluid and time scale of the flow), Magnetic Body force parameter, stream-wise variable, and Prandtl number on thermo fluid characteristics are studied graphically and via tables. A weak elevation in temperature accompanies increasing Weissenberg number, whereas a significant acceleration in the flow is computed near the vertical plate surface with increasing Weissenberg number. Nusselt number is reduced with increasing Weissenberg number. Skin friction and Nusselt number are both reduced with increasing Magnetic field effect. The model is relevant to the simulation of Magnetic polymer materials processing.
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mathematical modelling of nonlinear thermal radiation effects on emhd peristaltic pumping of viscoelastic dusty fluid through a porous medium duct
Engineering Science and Technology an International Journal, 2017Co-Authors: M M Bhatti, A Zeeshan, N Ijaz, A KadirAbstract:Biologically-inspired propulsion systems are currently receiving significant interest in the aerospace sector. Since many spacecraft propulsion systems operate at high temperatures, thermal radiation is important as a mode of heat transfer. Motivated by these developments, in the present article, the influence of nonlinear thermal radiation (via the Rosseland diffusion flux model) has been studied on the laminar, incompressible, dissipative EMHD (Electro-magneto-hydrodynamic) peristaltic propulsive flow of a non-Newtonian (Jefferys viscoelastic) dusty fluid containing solid particles through a porous planar channel. The fluid is electrically-conducting and a constant static Magnetic field is applied transverse to the flow direction (channel walls). Slip effects are also included. Magnetic induction effects are neglected. The mathematical formulation is based on continuity, momentum and energy equations with appropriate boundary conditions, which are simplified by neglecting the inertial forces and taking the long wavelength and lubrication approximations. The boundary value problem is then rendered non-dimensional with appropriate variables and the resulting system of reduced ordinary differential equations is solved analytically. The impact of various emerging parameters dictating the non-Newtonian propulsive flow i.e. Prandtl number, radiation parameter, Hartmann number, permeability parameter, Eckert number, particle volume fraction, electric field and slip parameter are depicted graphically. Increasing particle volume fraction is observed to suppress temperature magnitudes. Furthermore the computations demonstrate that an increase in particle volume fraction reduces the pumping rate in retrograde pumping region whereas it causes the opposite effect in the co-pumping region. The trapping mechanism is also visualized with the aid of streamline contour plots. Increasing thermal radiation elevates temperatures. Increasing Hartmann (Magnetic Body force) number decreases the size of the trapping bolus whereas the quantity of the does not effected. Conversely increasing particle volume fraction reduces the magnitude of the trapping bolus whereas the number of trapped bolus remains constant.
