Aaqib Majeed - Academia.edu (original) (raw)

Papers by Aaqib Majeed

Alexandria Engineering Journal, 2016

The purpose of the present paper was to investigate the flow and heat transfer of Jeffery fluid p... more The purpose of the present paper was to investigate the flow and heat transfer of Jeffery fluid past a linearly stretching sheet with the effect of a magnetic dipole. The governing differential equations of motion and heat transfer are transformed into nonlinear coupled ordinary differential equations (ODEs) using appropriate similarity transformations. Then the ODEs are solved by adopting two different schemes, Runge-Kutta with shooting technique and series solution based on GA and NM. The effect of various physical parameters including ferromagnetic interaction parameter (b), Deborah number (c 1), Prandtl number (Pr), suction/injection parameter (S), ratio of relaxation to retardation times (k 2) on velocity and temperature profiles is illustrated graphically and in tabular form by considering two types of thermal process namely prescribed surface temperature (PST) and prescribed heat flux (PHF). Comparison with available results for particular cases is found an excellent agreement.

International journal of innovation and scientific research, 2016

DC to AC Converters generate discrete output wave forms. Mostly, neither the voltage nor the curr... more DC to AC Converters generate discrete output wave forms. Mostly, neither the voltage nor the current have the desired wave forms and also produce harmonic, power losses and high frequency noise. The non-sinusoidal wave form will make the electronic equipment to burn early. The loss of power will make the system uneconomical. All this include the poor performance of the existing DC to AC converters. In this paper, pure sine wave with voltage control for nonlinear load applications is presented for single phase full bridge inverter. PWM (Pulse Width Modulation) technique is used to control voltage while pure sine wave obtained by using two techniques one is through band pass filter (as high value inductor are rarely available and also difficult to build thus combination of high pass and low pass filter used) at output and other is by DAC (Digital to Analog Conversion). Moreover, the proposed controller used for output voltage control is PID. It works as voltage controller for inverter...

Mathematical Problems in Engineering, 2021

In this article, MHD flow of silver/water nanofluid past a stretched cylinder under the impact of... more In this article, MHD flow of silver/water nanofluid past a stretched cylinder under the impact of thermal radiation with chemical reaction and slip condition is studied. The impact of Soret and Dufour effect is also analyzed during this flow. The uniqueness of the given problem is enlarged with the insertion of variable magnetic field, free stream velocity, thermal slip condition, and nonlinear thermal radiation. The PDEs are converted to ODEs by using suitable similarity transformation. The nonlinear system of ODEs is solved by applying convergent homotopy analysis method (HAM). The velocity, temperature, and concentration profiles for the free stream and at the plate are discussed through graphs and numerical tables. It is found that velocity field reduces, while the temperature profile rises for the increasing values of magnetic parameter. It is examined that effects of curvature on frication factor are increasing. Furthermore, temperature profile increases for greater Brownian m...

Journal of Magnetics, 2021

Mathematics and Computers in Simulation, 2021

Abstract In this paper, the effect of viscous dissipation and Joule heating on magneto-hydrodynam... more Abstract In this paper, the effect of viscous dissipation and Joule heating on magneto-hydrodynamic (MHD) nanofluid flow towards a vertical sinusoidal wavy surface has been investigated numerically. The wavy surface is considered to be heated with uniform flux. Effects of radiation and nanoparticle volume concentration are also considered. The fluid flow over the surface geometry is designed through the highly non-linear partial differential equations, and governing equations must be transformed into a dimensionless non-similar system of equations to get a better solution by applying the highly efficient well-known Keller-box scheme. In this regard, the numerical solutions are obtained for a concentration of mass fluid, velocity profile, temperature profile, local skin friction number coefficient, local Nusselt number, and Sherwood number shown graphically. Connected parameters involve in the modelled problem such as heat generation parameter, radiative conduction flow parameter, the amplitude of the waviness of the surface, Prandtl number, Brownian motion parameter, Buoyancy ratio, magnetic parameter, Thermophoresis parameter and the Lewis number for momentum, temperature profile, and concentration profile of the fluid through different graphs are explained. In this process, certain iterations were performed for different step sizes in the direction of η = 0 . 01 and x = 0 . 005 , respectively. So, keeping this in view to get the more accurate results with all parameters considered, 0 ≤ M ≤ 1 , 0 ≤ R d ≤ 1 , 0 ≤ Q ≤ 1 , 0 . 01 ≤ α ≤ 0 . 04 , 0 ≤ L e ≤ 40 , 0 . 1 ≤ N b ≤ 0 . 7 , 0 . 1 ≤ N t ≤ 0 . 7 , 0 . 1 ≤ N r ≤ 0 . 7 , 0 . 1 ≤ E c ≤ 0 . 4 , 0 . 1 ≤ J ≤ 0 . 4 , . The obtained results illustrate that Nusselt number, Sherwood number, and velocity profile decreases respectively with the increase of waviness amplitude, but skin friction changes its behaviour to wavier. Also, temperature and concentration profiles increase respectively with enhancing the value of the amplitude of waviness. Finally, it is noted that Nusselt number and Sherwood number decrease for higher values of the Brownian parameter. But after a specific value of x, the trend of Sherwood number increases. However, the behaviour of skin friction decreases, but in a precise manner, it remains almost unchanged.

Alexandria Engineering Journal, 2021

Abstract Seismic numerical modeling technique provide most suitable way for the simulation of wav... more Abstract Seismic numerical modeling technique provide most suitable way for the simulation of wave propagation through subsurface rocks and play an essential role in seismic interpretation, seismic inversion and in evaluating and designing a seismic survey. In order to delineate subsurface more precisely, different approaches are proposed for numerical modeling in which the solutions of Biot’s poroelastic equation are given by using reflectivity, finite element and finite difference algorithms. In current study, a finite difference forward modeling method is proposed to quantify the variation in wave properties during its propagation in a poroelastic media exhibiting mesoscopic heterogeneity due to the existence of three phase fluids. The Biot’s poroelastic wave equations are resolved and a generalized finite difference technique in time domain (FDTD) is used to examine seismic responses in a poroelastic media saturated with three phase fluids. So that the ability to detect geo-fluids through forward modeling technique can be improved. The accuracy of the simulation will lay a good foundation for the follow up work and will enhance our understandings about wave propagation through multi-phase poroelastic media and will also assist in detection and discrimination between fluids of different nature. Also, the proposed approach is of great significance for imaging and prediction of subsurface structures and distribution of fluids.

Journal of Thermal Analysis and Calorimetry, 2020

Bioconvection flows are very much related to engineering and real-life phenomena, for example, in... more Bioconvection flows are very much related to engineering and real-life phenomena, for example, in the design of bio-cells, bio-conjugates and bio-microsystems, and become a hot topic in the current research. Therefore, the purpose of the present investigation is to explore theoretically the time-dependent electrically conducting flow with heat and mass transfer containing gyrotactic microorganism with activation energy toward an elongated surface with the effect of thermal radiation. Impact of velocity, thermal and concentration slips are also taken into account. The classical problem of Navier Stokes equations in the present model is reduced into ODEs by employing similarity approach. Numerical simulations are performed via boundary value problem solver based on finite difference numerical scheme using MATLAB. Impact of convergence parameters like motile microorganisms, concentration, temperature and velocity fields is elaborated through graphically and in the form of tables. The significant outcomes display that the density of motile microorganisms decreases with Peclet number and bioconvection Lewis number, while opposite behavior is noted for thermal buoyancy and buoyancy force ratio parameter on velocity profile.

International Journal of Numerical Methods for Heat & Fluid Flow, 2020

Purpose The purpose of this study is to examine the impact of activation energy with binary chemi... more Purpose The purpose of this study is to examine the impact of activation energy with binary chemical reaction for unsteady flow on permeable stretching surface. Design/methodology/approach The simultaneous effects of multiple slip and magneto-hydrodynamic effects at the boundary are taken into account. The thermal buoyancy parameter and thermal radiation are included in both energy and momentum equations, while expression of activation energy is considered in concentration equation. Three-stage Lobatto IIIa finite difference collocation technique with bvp4c MATLAB package is used to obtained numerical results. Findings The influence of key elements (Schmidt number, buoyancy force ratio factor, factor of radiation, magnetic element, unsteadiness factor, suction/injection parameter, Prandtl number, activation energy, chemical reaction rate parameter, heat source and sink parameters, velocity, thermal and concentration slips, porosity parameter and temperature difference parameter) on ...

Journal of Thermal Analysis and Calorimetry, 2019

In the present article, an analysis has been performed to discuss the impact of steady mixed conv... more In the present article, an analysis has been performed to discuss the impact of steady mixed convection with Darcy–Forchheimer flow towards linear surface. Investigation has been achieved in the presence of Arrhenius activation energy and radiative heat flux which are associated with the heat and mass transport analysis which has not been performed so far. Porous media features are elaborated by utilizing Darcy–Forchheimer relation. Boundary-layer idea is employed for the simplification of governing expressions. The resulting set of mathematical expression is now solved with the help of bvp4c MATLAB package which applies a three-stage Lobatto IIIa finite-difference collocation scheme. Diagrams are drawn against pertinent parameters such as buoyancy forces ratio parameter, mixed convection parameter, porosity parameter, local inertia coefficient, activation energy, chemical reaction rate constant, Schmidt number, temperature difference ratio, exponentially fitted constant, magnetic parameter, radiation parameter, first-order and second-order slip parameter, suction or injection parameter and Prandtl number. It is observed that both mixed convection and activation energy parameters have an opposite impact on species profile. Also the present results are compared with those available in the literature for some cases, and an excellent agreement is found between them.

Journal of Magnetics, 2019

Mechanics & Industry, 2019

This article is focused on Maxwell ferromagnetic fluid and heat transport characteristics under t... more This article is focused on Maxwell ferromagnetic fluid and heat transport characteristics under the impact of magnetic field generated due to dipole field. The viscous dissipation and heat generation/absorption are also taken into account. Flow here is instigated by linearly stretchable surface, which is assumed to be permeable. Also description of magneto-thermo-mechanical (ferrohydrodynamic) interaction elaborates the fluid motion as compared to hydrodynamic case. Problem is modeled using continuity, momentum and heat transport equation. To implement the numerical procedure, firstly we transform the partial differential equations (PDEs) into ordinary differential equations (ODEs) by applying similarity approach, secondly resulting boundary value problem (BVP) is transformed into an initial value problem (IVP). Then resulting set of non-linear differentials equations is solved computationally with the aid of Runge–Kutta scheme with shooting algorithm using MATLAB. The flow situatio...

Mechanics of Advanced Materials and Structures, 2018

In this article, vibration analysis of single-walled carbon nanotubes (SWCNTs) based on Love's th... more In this article, vibration analysis of single-walled carbon nanotubes (SWCNTs) based on Love's thin shell theory has been investigated along with five sort of boundary conditions (S-S), (C-C), (C-F), (C-Sl), and (F-S). Three different shapes such as Armchair, Zigzag, and Chiral are taken into account under the influence of Winkler and Pasternak foundations. The wave propagation approach is employed to formulate the eigenvalue problem. MATLAB software package in used to obtain the vibrational natural frequencies of SWCNTs. The axial modal dependence is measured by the complex exponential functions implicating the axial modal numbers. Nomenclature E = Young's modulus h = shell thickness L = shell length v = Poisson's ratio ω = natural angular frequency E, v, ρ = effective material quantities L/R = length-to-radius ratio n = circumferential wave number Eh = in-plane rigidity ρh = mass density per unit lateral area θ = circumferential coordinate u(x, θ , t) = displacement functions in x direction v(x, θ , t) = displacement functions in θ direction w(x, θ , t) = displacement functions in z direction

Canadian Journal of Physics, 2019

Non-Newtonian fluid model is intricate, nonlinear, and interesting to study because of the presen... more Non-Newtonian fluid model is intricate, nonlinear, and interesting to study because of the presence of rheological flow parameters and viscoelastic properties, which tend to emerge and make industrial flows considerably more complex to explain accurately. Improvement of industrial applications, such as glass fabrication, is an important consequence of this study. In this manuscript, we have explored the combined impact of the higher order slip with variable transverse magnetic field flow and thermal transport using Roseland’s heat flux of the Eyring–Powell fluid with assumption of boundary layer, on nonlinear stretching sheet, in which fluid is considered electrically conducting. The transformed ordinary differential equations are solved by three-stage Lobatto IIIa collocation finite difference scheme using MATLAB. The impact of pertinent flow parameters on dimensionless velocity and temperature profiles is presented graphically and discussed in detail. Obtained results confirm that...

Journal of Magnetism and Magnetic Materials, 2018

Abstract The persistence of the current article is to discuss the iron nanoparticles' shape i... more Abstract The persistence of the current article is to discuss the iron nanoparticles' shape in flows due to highly oscillating magnetic field over a stretchable rotating disk. For ferrofluid, water is considered as base fluid with suspension of iron nanoparticles having sphere, oblate ellipsoid and prolate ellipsoid shapes with different sizes. The impact of the nanoparticles' shape on velocity and temperature profiles, convective heat transfer coefficient, radial and transverse shear stress is deliberated through graphs and tables. The presence of highly oscillating magnetic field forces the particles to rotate faster than the fluid and, as a result, the total viscosity is certainly reduced. The governing equations, which are firstly modeled and thereafter converted into nonlinear ordinary differential equations in dimensionless form using similarity approach, are analytically solved using the Mathematica package BVPh 2.0 which is based on the homotopy analysis method (HAM).

Journal of Molecular Liquids, 2018

Abstract Magnetic nanofluids are used in cancer therapeutics by utilizing cancer imaging and drug... more Abstract Magnetic nanofluids are used in cancer therapeutics by utilizing cancer imaging and drug delivery. These are also used to kill cancerous cells without affecting the nearby healthy cells by producing higher temperatures around tumor. This investigation aims to explore the heat transfer in non-Darcy porous medium for magnetic nanofluid flowing due to external magnetic field. Nanoparticle shapes and their properties are also considered. Vorticity stream function formulation is also employed. The solutions of the resulting system of equations are found by CVFEM. Illustrations are outlined pictorially for numerous physical parameters namely, Rayleigh number, radiation parameter, Darcy number, Fe3O4-water based volume concentration and Hartmann numbers. Outcomes indicate that augmenting in Hartmann number results in reduce in velocity of nanofluid and heat transfer rate. The nanoparticle with shape Platelet gives maximum heat transfer rate.

Case Studies in Thermal Engineering, 2018

This paper is communicated theoretically to study the collective effects of Arrhenius activation ... more This paper is communicated theoretically to study the collective effects of Arrhenius activation energy and binary chemically reactive species in the presence of the second order momentum slip model which has not been studied so far. To support these declaration in addition with electrically conducting boundary layer flow and heat transport have considered towards an exponential stretching sheet. The current study incorporates the impact of activation energy, temperature difference ratio parameter, 1st and 2nd order slip parameter, chemical reaction rate on fluid velocity, fluid temperature and concentration of chemical species are elaborated through graphically and discussed in detail. Appropriate transformations are betrothed to acquire nonlinear highly coupled ordinary differential equations (ODE's) from partial differential equations which are then solved numerically by employing finite difference collocation process that apply three-stage Lobatto IIIa scheme. The obtained results confirm that an excellent agreement is achieved with those available in open literature. It is found that concentration profile decreases in the presence of chemical reaction rate and temperature difference ratio parameter whereas opposite demeanour is seen for activation energy.

Journal of the National Science Foundation of Sri Lanka, 2018

The aim of the present paper was to investigate the boundary layer flow and heat transfer in a du... more The aim of the present paper was to investigate the boundary layer flow and heat transfer in a dusty fluid with ferromagnetic particles over a flat stretching sheet including the effect of magnetic dipole. By using suitable similarity transformations, the governing partial differential equations of momentum and energy were reduced into non-linear ordinary differential equations. The resulting differential equations with corresponding boundary conditions were solved numerically by employing shooting based fourth order Runge-Kutta method. The effect of controlling parameters such as ferromagnetic interaction parameter, mixed convection parameter, Eckert number, Prandtl number, the number of dust particles and heat generation/absorption parameter on the temperature and velocity profiles are considered graphically for two types of heating processes, namely, the prescribed surface temperature (PST) and the prescribed heat flux (PHF). The value of skin friction coefficient and Nusselt number are presented in tabular form for different values of the governing parameters. It is found that the value of local Nusselt number increases with an increase of the value of heat source/sink parameter for both PST and PHF cases. The present results were compared with previously published data for a special case and an excellent agreement was found.

Engineering Science and Technology, an International Journal, 2017

In this article, the influence of chemical reaction and heat transfer analysis of Maxwell saturat... more In this article, the influence of chemical reaction and heat transfer analysis of Maxwell saturated Ferrofluid flow over a stretching sheet under the influence of magnetic dipole with Soret and suction effects are investigated. The sheet is assumed to be permeable in a semi-infinite domain. Firstly, partial differential equations of mass, momentum and concentration for the governing flow problem are modelled and converted into a system of differential equations by utilizing similarity approach. Then the solution of resulting non-linear differential equations is solved by efficient Runge-Kutta technique based on shooting algorithm with the help of MATLAB. Effect of all appropriate parameters like ferromagnetic interaction parameter, chemical reaction parameter, Maxwell parameter, Soret number, suction parameter, Maxwell parameter, Schmidt number, and suction parameter on velocity, temperature and concentration field are confirmed through graphs and table. From the present conclusions, it is examined that by increasing the Maxwell parameter there is a decrease in the fluid velocity and boundary layer thickness. On the other hand, the uprising behaviour is prominent for both temperature and concentration profiles. Also predicted that there is an enhancement in skin friction coefficient and rate of heat transfer by enlarging suction parameter, but opposite trend is noted for Sherwood number. Also noted that the values of Prandtl are taken ranges from 0.72 to 10. The Nusselt number increases from 1.09 to 4.80.

Journal of Molecular Liquids, 2016

This paper is mainly focused on unsteady boundary layer flow ferromagnetic fluid and heat transfe... more This paper is mainly focused on unsteady boundary layer flow ferromagnetic fluid and heat transfer past a stretching surface with the influence of magnetic dipole. The momentum and energy equation are expressed as five parameter problem, which is solved numerically by employing shooting based RKF-45 method. Two different types of thermal boundary conditions are studied, namely, (i) prescribed surface temperature (PST) and (ii) prescribed heat flux (PHF). The effects of the various emerging parameters involving in the problem on dimensionless velocity and temperature distributions are illustrated graphically and tabular form. It was establish that the key factor of the magneto-thermomechanical intervention is to slow down the fluid motion in the comparison to the simple hydrodynamic. Comparisons of present results were made with those available in open literature and found excellent agreement.

Neural Computing and Applications, 2017

This article examines the boundary layer flow of magnetic nanofluid over a stretching surface wit... more This article examines the boundary layer flow of magnetic nanofluid over a stretching surface with velocity slip condition. Water is selected as a base liquid whereas ferromagnetic, paramagnetic, diamagnetic, anti-ferromagnetic, and ferrimagnetic are chosen as nanoparticles. The use of magnetic nanoparticle is to control the flow and heat transfer process via external magnetic field. The governing partial differential equations are transformed into highly nonlinear ordinary differential equations. Numerical solution of the resulting problem is obtained. Effect of emerging physical parameters on velocity, temperature, skin friction coefficient, and Nusselt number are explained graphically. We observe that diamagnetic case has gained maximum thermal conductivity as compared with the other ones. Furthermore, skin friction coefficient increases with the variation of β and K 1 , and opposite interpretation is noted for Nusselt number.