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1 – 10 of over 1000Sajjad Haider, Adnan Saeed Butt, Imran Syed Muhammad, Asif Ali, Yun-Zhang Li, Syed Muhammad Ali Naqvi and Muhammad Adnan Qaiser
The purpose of this study is to theoretically probe the shape impacts of nano-particle on boundary layer flow of nano-fluid toward a stretching cylinder with heat-transmission…
Abstract
Purpose
The purpose of this study is to theoretically probe the shape impacts of nano-particle on boundary layer flow of nano-fluid toward a stretching cylinder with heat-transmission effects. The base fluid used for this study is pure water, and aluminum oxide nano-particles are suspended in it. Four different shapes of nano-particle, namely, cylindrical, brick, platelets and blades, are considered to carry out the study.
Design/methodology/approach
The problem is modelled mathematically and the nonlinear system of equations is attained by using appropriate transmutations. The solution of transmuted equations is achieved by utilizing a shooting technique with Fourth-Fifth order Runge–Kutta Fehlberg scheme. Numerically attained results are elucidated through graphs and tables which are further compared under limiting cases with existing literature to check the validity of the results.
Findings
It is observed that fluid velocity and temperature of cylindrical shaped water nano-fluids are more than the nano-fluid having brick-shaped nano-particles. Moreover, it is seen that the nano-fluids suspended with platelets-shaped nano-particles have higher velocity and temperature than the nano-fluids containing blade-shaped nano-particles. The curvature parameter and nano-particles volume fraction have increasing effects on flow velocity and temperature of nano-fluids containing all types of nano-particle shapes.
Originality/value
Numerous authors have examined the impacts of nano-particle shapes on characteristics of heat transfer and fluid flow. However, to the best of the authors’ knowledge, the shape impacts of nano-particles on boundary layer flow of nano-fluid toward a stretching cylinder with heat-transmission effects have not been discussed. So, to fulfill this gap, the present paper explicates the impacts of various nano-particle shapes on Al2O3–water-based nano-fluid flow past a stretching cylinder with heat-transfer effects.
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Abstract
Purpose
The purpose of this article is to analyze the heat and mass transfer with entropy generation during magnetohydrodynamics (MHD) flow of non-Newtonian Sisko nanofluid over a linearly stretching cylinder under the influence of velocity slip, chemical reaction and thermal radiation. The Brownian motion, thermophoresis and activation energy are assimilated in this nanofluid model. Convective boundary conditions on heat and mass transfer are considered. The physical model may have diverse applications in several areas of technology underlying thermohydrodynamics including supercritical fluid extraction, refrigeration, ink-jet printing and so on.
Design/methodology/approach
The dimensional governing equations are nondimensionalized by using appropriate similarity variables. The resulting boundary value problem is converted into initial value problem using the method of superposition and numerically computed by employing well-known fourth-order Runge–Kutta–Fehlberg approach along with shooting technique (RKF4SM). The quantitative impacts of emerging physical parameters on the velocity, temperature, concentration, skin friction coefficient, Nusselt number, Sherwood number, entropy generation rate and Bejan number are presented graphically and in tabular form, and the salient features are comprehensively discussed.
Findings
From graphical outcomes, it is concluded that the slip parameters greatly influence the flow characteristics. Fluid temperature is elevated with rising radiation parameter and thermal Biot number. Nanoparticle concentration is reported in decreasing form with activation energy parameter. Entropy is found to be an increasing function of magnetic field, Brownian motion and material parameters. The entropy is less generated for shear-thinning fluid compared to shear-thickening as well as Newtonian fluids in the system.
Originality/value
Till now no study has been documented to explore the impact of binary chemical reaction with Arrhenius activation energy on entropy generation in an MHD boundary layer flow of non-Newtonian Sisko nanofluid over a linear stretching cylinder with velocity slip and convective boundary conditions.
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T. Hayat, M. Waqas, Sabir Ali Shehzad and A. Alsaedi
The purpose of this paper is to examine the effects of variable thermal conductivity in mixed convection flow of viscoelastic nanofluid due to a stretching cylinder with heat…
Abstract
Purpose
The purpose of this paper is to examine the effects of variable thermal conductivity in mixed convection flow of viscoelastic nanofluid due to a stretching cylinder with heat source/sink.
Design/methodology/approach
The authors have computed the existence of the solution for Walter’s B and second grade fluids corresponding to Pr=0.5 and Pr=1.5. Skin-friction coefficient, local Nusselt and Sherwood numbers are computed numerically for different values of emerging parameters.
Findings
A comparative study with the existing solutions in a limiting sense is made and analyzed. The authors found that the dimensionless velocity filed and momentum boundary layer thickness are increased when the values of viscoelastic parameter increase. The present non-Newtonian fluid flow reduces to the viscous flow in the absence of viscoelastic parameter. The larger values of viscoelastic parameter corresponds to the higher values of local Nusselt and Sherwood numbers.
Originality/value
No such analysis exists in the literature yet.
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M.Y. Malik, Arif Hussain, T. Salahuddin and M. Awais
– The purpose of this paper is to examine the Sisko fluid model over a stretching cylinder with heat transfer and magnetohydrodynamics.
Abstract
Purpose
The purpose of this paper is to examine the Sisko fluid model over a stretching cylinder with heat transfer and magnetohydrodynamics.
Design/methodology/approach
The boundary layer approach is employed to simplify the governing equations. Suitable similarity transformations are used to transform the governing partial differential equations into ordinary differential equations. In order to solve this system of ordinary differential equations numerically, shooting method in conjunction with Runge-Kutta-Fehlberg method is used.
Findings
The effects of physical parameters involved in velocity and temperature profiles are shown through graphs. It is observed that Sisko fluid parameter and curvature parameter enhances fluid velocity while motion of fluid is retarded by increasing magnetic field strength. Additionally temperature of fluid raise with curvature parameter while it fall down for larger values of Prandtl number. Skin friction coefficient and Nusselt number are computed and presented in graphs and tables for further analysis. It can be seen that curvature parameter increases both skin friction and Nusselt number while magnetic field and Prandtl number decayed skin friction and Nusselt number, respectively. Also Sisko parameter enlarges skin friction coefficient. The accuracy of solution is verified by comparing it with existing literature.
Originality/value
The computed results are interested for industrial and engineering processes, especially in cooling of nuclear reactors.
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Nur Adilah Liyana Aladdin and Norfifah Bachok
This paper aims to explore on stagnation point flow of Ag-CuO/water over a horizontal stretching/shrinking cylinder by adding the effect of chemical reaction, B together with the…
Abstract
Purpose
This paper aims to explore on stagnation point flow of Ag-CuO/water over a horizontal stretching/shrinking cylinder by adding the effect of chemical reaction, B together with the magnetic field, M.
Design/methodology/approach
A set of reduced ordinary differential equations from the governing equations of partial differential equations is obtained through similarities requirements. The resulting equations are solved using bvp4c in MATLAB2019a. The impact of various physical parameters such as curvature parameter,
Findings
The findings expose that the duality of solutions appears in a shrinking region (
Practical implications
The hybrid nanofluid has widened its applications such as in electronic cooling, manufacturing, automotive, heat exchanger, solar energy, heat pipes and biomedical, as their efficiency in the heat transfer field is better compared to nanofluid.
Originality/value
The findings on stagnation point flow of Ag-CuO/water over a horizontal stretching/shrinking cylinder with the effect of chemical reaction, B and magnetic field, M is new and the originality is preserved for the benefits of future researchers.
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S.S. Ghadikolaei, Kh. Hosseinzadeh and D.D. Ganji
The purpose of this study is, mixed convection on magnetohydrodynamic (MHD) flow of Eyring–Powell nanofluid over a stretching cylindrical surface in the presence of thermal…
Abstract
Purpose
The purpose of this study is, mixed convection on magnetohydrodynamic (MHD) flow of Eyring–Powell nanofluid over a stretching cylindrical surface in the presence of thermal radiation, chemical reaction, heat generation and Joule heating effect is investigated and analyzed. The Brownian motion and thermophoresis phenomenon are used to model nanoparticles (Buongiorno’s model).
Design/methodology/approach
The numerical method is applied to solve the governing equations. Obtained results from the effects of different parameters changes on velocity, temperature and concentration profiles are reported as diagrams.
Findings
As a result, velocity profile has been reduced by increasing the Hartman number (magnetic field parameter) because of the existence of Lorentz force and increasing Eyring–Powell fluid parameter. In addition, the nanoparticle concentration profile has been reduced because of increase in chemical reaction parameter. At the end, the effects of different parameters on skin friction coefficient and local Nusselt number are investigated.
Originality/value
Eyring–Powell nanofluid and MHD have significant influence on flow profile.
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Ixchel G. Ramirez-Alpizar, Kensuke Harada and Eiichi Yoshida
The aim of this work is to develop a simple planner that is able to automatically plan the motion for a dual-arm manipulator that assembles a ring-shaped elastic object into a…
Abstract
Purpose
The aim of this work is to develop a simple planner that is able to automatically plan the motion for a dual-arm manipulator that assembles a ring-shaped elastic object into a cylinder. Moreover, it is desirable to keep the amount of deformation as small as possible, because stretching the object can permanently change its size thus failing to perfectly fit in the cylindrical part and generating undesired gaps between the object and the cylinder.
Design/methodology/approach
The assembly task is divided in two parts: assembly task planning and assembly step planning. The first one computes key configurations of the robot’s end-effectors, and it is based on a simple heuristic method, whereas the latter computes the robot’s motion between key configurations using an optimization-based planner that includes a potential-energy-based cost function for minimizing the object’s deformation.
Findings
The optimization-based planner is shown to be effective for minimizing the deformation of the ring-shaped object. A simple heuristic approach is demonstrated to be valid for inserting deformable objects into a cylinder. Experimental results show that the object can be kept without deformation for the first part of the assembly task, thus reducing the time it is being stretched.
Originality value
A simple assembly planner for inserting ring-shaped deformable objects was developed and validated through several experiments. The proposed planner is able to insert ring-shaped objects without using any sensor (visual and/or force) feedback. The only feedback used is the position of the robot’s end-effectors, which is usually available for any robot.
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Tasawar Hayat, Muhammad Farooq and A. Alsaedi
– The purpose of this paper is to focus on the stratified phenomenon through vertical stretching cylinder in the region of stagnation point with slip effects.
Abstract
Purpose
The purpose of this paper is to focus on the stratified phenomenon through vertical stretching cylinder in the region of stagnation point with slip effects.
Design/methodology/approach
Homotopy analysis method is used to find the series solutions of the governing equations.
Findings
Velocity profile decreases with an increase in stratified parameters due to temperature and concentration. Velocity and thermal slips cause a reduction in the velocity profile. Thermally stratified and thermal slip parameters reduce the temperature field.
Originality/value
The present analysis has not been existed in the literature yet.
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M. Nawaz, A Zeeshan, R Ellahi, S Abbasbandy and Saman Rashidi
The purpose of this paper is to study the Joules heating effects on stagnation point flow of Newtonian and non-Newtonian fluids over a stretching cylinder by means of genetic…
Abstract
Purpose
The purpose of this paper is to study the Joules heating effects on stagnation point flow of Newtonian and non-Newtonian fluids over a stretching cylinder by means of genetic algorithm (GA). The main emphasis is to find the analytical and numerical solutions for the said mathematical model. The work undertaken is a blend of numerical and analytical studies. Effects of active parameters such as: Hartmann number, Prandtl number, Eckert number, Nusselt number, Skin friction and dimensionless fluids parameters on the flow and heat transfer characteristics have been examined by graphs and tables. Compression is also made with the existing benchmark results.
Design/methodology/approach
Analytical solutions of non-linear coupled equations are developed by optimal homotopy analysis method (OHAM). A very effective and higher order numerical scheme hybrid GA and Nelder-Mead optimization Algorithms are used for numerical investigations.
Findings
An excellent agreement with the existing results in limiting sense is noted. It is observed that the radial velocity is an increasing function of dimensionless material parameters α 1, α 2 and β. Temperature increases by increasing the values of M, Pr, Ec and γ. Non-Newtonian parameter β has similar effects on skin friction coefficient and Nusselt number. The wall heat transfer rate is a decreasing function of A and ß whereas it increases by increasing conjugate parameter γ.
Originality/value
The problem under consideration has been widely studied by many investigators due to its importance and engineering applications. But most of the studies as the authors have documented are for Newtonian or viscous fluids. But no such analysis is available in the literature which can describe the Joules heating effects on stagnation point flow of Newtonian and non-Newtonian fluids over a stretching cylinder by means of GA.
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Tasawar Hayat, Zeenat Bashir, Sumaira Qayyum and Ahmed Alsaedi
This paper aims to explore the study of magnetohydrodynamic viscous fluid flow past on a stretching cylinder with nonlinear thermal radiation having gyrotactic microorganisms.
Abstract
Purpose
This paper aims to explore the study of magnetohydrodynamic viscous fluid flow past on a stretching cylinder with nonlinear thermal radiation having gyrotactic microorganisms.
Design/methodology/approach
Appropriate transformations reduce the nonlinear partial differential equation to ordinary ones. Subsequent nonlinear equations are calculated to get convergent series solutions.
Findings
Fluid velocity declines for elevating values of magnetic field parameter. For larger values of curvature parameter near the cylinder temperature reduces.
Originality/value
To the best of the authors’ knowledge, magnetohydrodynamic boundary layer flow of viscous fluid by nonlinear stretching cylinder with nonlinear thermal radiation having gyrotatic microorganisms is not studied yet. The purpose is to study this.
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