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Article
Publication date: 13 January 2022

W. Stanly and R. Vasanthakumari

This study aims to focus on the effect of hall currents on the thermal stability of a couple-stress fluid with a uniform horizontal magnetic field.

31

Abstract

Purpose

This study aims to focus on the effect of hall currents on the thermal stability of a couple-stress fluid with a uniform horizontal magnetic field.

Design/methodology/approach

The thermal perturbation method is used for the analytical solution. The analysis is administered within the framework of linear stability theory and normal mode technique on the convection for a fluid layer contained between two boundaries for which an exact solution is obtained.

Findings

For the case of stationary convection, a dispersion relation governing the effect of hall currents magnetic field and couple stress are derived. Results from the current study concluded that magnetic field has stabilizing effect whereas hall currents are found to have a destabilizing effect on the system. Couple stress, however, has a dual character in contrast to its stabilizing effect in the absence of hall currents. The Oscillatory modes are introduced due to the presence of a magnetic field in the system. Graphs are plotted by giving numerical values to the parameters to depict the stability characteristics in each case.

Originality/value

This research paper is new and original.

Details

World Journal of Engineering, vol. 19 no. 5
Type: Research Article
ISSN: 1708-5284

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Article
Publication date: 12 February 2018

W. Stanly and R. Vasanthakumari

The purpose of this paper is used to study the combined effect of solute gradient and magnetic field on dusty couple-stress fluid in the presence of rotation through a porous…

33

Abstract

Purpose

The purpose of this paper is used to study the combined effect of solute gradient and magnetic field on dusty couple-stress fluid in the presence of rotation through a porous medium.

Design/methodology/approach

The perturbation technique (experimental method) is applied in this study.

Findings

For the case of stationary convection, solute gradient and rotation have stabilizing effect, whereas destabilizing effect is found in dust particles in the system. Couple stress and medium permeability both have dual character to its stabilizing effect in the absence of magnetic field and rotation. Magnetic field succeeded in establishing a stabilizing effect in the absence of rotation.

Originality/value

The results are discussed by allowing one variable to vary and keeping other variables constant, as well as by drawing graphs.

Details

World Journal of Engineering, vol. 15 no. 1
Type: Research Article
ISSN: 1708-5284

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Article
Publication date: 24 December 2024

Lawanya T., Pragya Pandey, Sangeetha S. and Kavitha D.

The current investigation is concerned with the Soret effect along with chemical reaction and radiation on flow of an electrically conductive, viscous fluid through a…

6

Abstract

Purpose

The current investigation is concerned with the Soret effect along with chemical reaction and radiation on flow of an electrically conductive, viscous fluid through a perpendicular plate, which is porous with oscillatory suction. The aim of this study is to investigate the effects of first-order temperature and chemical reaction and the transverse magnetic field characteristics. The closed form of solutions are obtained using the governing equations for concentration, energy and momentum. The perturbation technique was applied to find the result for the velocity field, temperature profiles and concentration distributions. Furthermore, the impact of various nondimensional parameters on fluid flow variables on the temperature field, velocity field and concentration dispersal was analyzed and the results were depicted graphically. Moreover, the skin friction and the rate of mass transfer (local Sherwood number) were analyzed using tables. In this work, an unsteady 2D flow of a laminar, viscid (Newtonian), electrically conducting fluid across a semi-infinite perpendicular permeable plate under motion in its plane (x-axis) embedded in a constant permeable structure was investigated.

Design/methodology/approach

In this work, an unstable 2D flow of a laminar, viscid (Newtonian), electrically conducting fluid across a semi-limitless perpendicular permeable plate under motion in its plane (x-axis) embedded in a constant permeable structure was investigated. The medium is considered to be under a transverse magnetic field with concentrated buoyancy effects. Furthermore, it is considered that no voltage is supplied, which indicates that there is no electrical field. The fluid properties are considered to be uniform. The concentration of the imparting species is considered as C′w at the plate; the concentration of the specimens away from the wall, C′8, is considered to be limitlessly less. The first-order chemical reaction is considered to be seen in the flow. Due to the semi-limitless plane surface considerations, the flow parameters are the functions of y′ and the time t′ only. The oscillatory suction velocity of the fluid at the plate normal to it is v′; initially, the plate relocates with the oscillatory velocity u′, in the direction of x that is in its plane. The pressure gradient is toward the x-axis.

Findings

The analytical solutions were obtained using the above analytical method for a few values of the governing parameters, such as the magnetic parameter (M), the permeability parameter (K), Schmidt number (Sc), chemical reaction parameter (Kr), Grashoff number for the concentration (Gm), Radiation parameter (N), Prandtl number (Pr), Chemical reaction parameter (Kr), Grashof number for heat transfer (Gr) and Heat source parameter (s). The influence of M, K, Sc, Kr, Gm, N, Pr, Kr, Gr and s on the fluid velocity, temperature and the concentration over the semi-infinite porous plate was obtained. Furthermore, the numerical computation was carried out using MATLAB.

Originality/value

In this chapter, the analysis of a free convective flow of a viscid compact, electrically conductive fluid was discussed during its flow through a plate in permeable condition with oscillatory suction with first-order temperature and chemical reaction and the transverse magnetic field. The problem formulation and the results were discussed. The following chapter explain the Soret effect of mass transfer and radiation with heat source on magnetohydrodynamics oscillatory viscoelastic fluid in a channel filled with porous medium.

Details

Aircraft Engineering and Aerospace Technology, vol. 97 no. 2
Type: Research Article
ISSN: 1748-8842

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Article
Publication date: 22 July 2014

R. Sekar and K. Raju

Thermoconvective instability with Soret effect in multi-component fluids has wide range of applications in heat and mass transfer. This work deals with the theoretical…

27

Abstract

Thermoconvective instability with Soret effect in multi-component fluids has wide range of applications in heat and mass transfer. This work deals with the theoretical investigation of the effect of magnetic field dependent (MFD) viscosity on Soret-driven ferrothermohaline convection heated and salted from below in an anisotropic porous medium subjected to a transverse uniform magnetic field. The resulting eigen value problem is solved using Brinkman model. An exact solution is obtained for the case of two free boundaries and the stationary and oscillatory instabilities are investigated by using linear stability analysis and normal mode technique for the vertical of anisotropic porous medium. The analysis has been made for different parameters like porosity, anisotropy, ratio of heat transport to mass transport, buoyancy magnetization, non-buoyancy magnetization, Soret parameter and Salinity Rayleigh number. The effect of MFD viscosity is assumed to be isotropy. It is found that the presence of MFD viscosity has a stabilizing effect, whereas magnetization has a destabilizing effect.

Details

World Journal of Engineering, vol. 11 no. 3
Type: Research Article
ISSN: 1708-5284

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Article
Publication date: 3 August 2021

D. Murugan and R. Sekar

The effect of magnetic field dependent (MFD) viscosity on the onset of convection in a ferromagnetic fluid layer heated from below saturating rotating porous medium in the…

42

Abstract

Purpose

The effect of magnetic field dependent (MFD) viscosity on the onset of convection in a ferromagnetic fluid layer heated from below saturating rotating porous medium in the presence of vertical magnetic field is investigated theoretically by using Darcy model. The resulting eigen value problem is solved using the regular perturbation technique. Both stationary and oscillatory instabilities have been obtained. It is found that increase in MFD viscosity and increase in magnetic Rayleigh number is to delay the onset of ferroconvection, while the nonlinearity of fluid magnetization has no influence on the stability of the system.

Design/methodology/approach

The thermal perturbation method is employed for analytical solution. A theory of linear stability analysis and normal mode technique have been carried out to analyze the onset of convection for a fluid layer contained between two impermeable boundaries for which an exact solution is obtained.

Findings

The conditions for the system to stabilize both by stationary and oscillatory modes are studied. Even for the oscillatory system of particular frequency dictated by physical conditions, the critical Rayleigh numbers for oscillatory mode of the system were found to be greater than for the stationary mode. The system gets destabilized for various physical parameters only through stationary mode. Hence, the analysis is restricted to the stationary mode. To the Coriolis force, the Taylor number Ta is calculated to discuss the results. It is found that the system stabilizes through stationary mode for values of and for oscillatory instability is favored for Ta > 104. Therefore the Taylor number Ta leads to stability of the system. For larger rotation, magnetization leads to destabilization of the system. The MFD viscosity is found to stabilize the system.

Originality/value

This research paper is new and original.

Details

World Journal of Engineering, vol. 19 no. 5
Type: Research Article
ISSN: 1708-5284

Keywords

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Article
Publication date: 12 November 2013

R. Sekar, D. Murugan and K. Raju

The study of ferrothermohaline convection, double diffusive convection with Soret and Dufour effects have drawn the attention of researchers for the past four decades due to their…

27

Abstract

The study of ferrothermohaline convection, double diffusive convection with Soret and Dufour effects have drawn the attention of researchers for the past four decades due to their remarkable applications. The Soret-driven ferrothermoconvective instability in a porous medium heated from below and salted from above has been analyzed using Darcy model for various values of parameters. A small thermal perturbation is applied to the basic state and linear stability analysis is used for which normal mode technique is applied. It is found that the presence of porous medium favours the onset of convection. The present work has been carried out both for oscillatory as well as stationary modes with graphical representation.

Details

World Journal of Engineering, vol. 10 no. 5
Type: Research Article
ISSN: 1708-5284

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Article
Publication date: 1 August 2014

K. Thirumurugan and R. Vasanthakumari

The Hydromagnetics instability of non-Newtonian Walters'B' viscoelastic rotating fluid in porous medium is considered. By applying normal mode analysis method, the dispersion…

37

Abstract

The Hydromagnetics instability of non-Newtonian Walters'B' viscoelastic rotating fluid in porous medium is considered. By applying normal mode analysis method, the dispersion relation has been derived and solved analytically. For stationary convection, the Walters'B' viscoelastic fluid behaves like an ordinary (Newtonian) fluid. The magnetic fluid is found to have a stabilizing effect on the thermal convection of Walters'B' fluid in the absence of rotation whereas the medium permeability has a destabilizing effect on the thermal convection of Walters'B' fluid in the absence of rotation, Rotation always has a stabilizing effect. The magnetic field, the medium permeability and rotation introduce oscillatory modes in the systems, which were non-existent in their absence.

Details

World Journal of Engineering, vol. 11 no. 4
Type: Research Article
ISSN: 1708-5284

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Article
Publication date: 16 August 2019

Sumit Gupta, Devendra Kumar, Jagdev Singh and Sandeep Gupta

The purpose of this paper is to investigate the effect of inclined magnetic field, variable viscosity and Cattaneo–Christov heat and mass flux theories on the steady MHD free…

65

Abstract

Purpose

The purpose of this paper is to investigate the effect of inclined magnetic field, variable viscosity and Cattaneo–Christov heat and mass flux theories on the steady MHD free convective boundary layer flow of viscous, incompressible and electrically conducting water-driven silver and titanium-oxide nanofluids over a vertical stretching sheet.

Design/methodology/approach

The boundary layer equations of momentum, energy and nanoparticle concentration are partial differential equations in nature, which are reduced to nonlinear ordinary differential equations by means of similarity transformations. The resulting nonlinear equations are solved analytically by means of optimal homotopy analysis method.

Findings

Assessments with numerical results are performed and are found to be in an excellent agreement. Numerical results of the skin friction factor, the local Nusselt number and the local Sherwood number are obtained through tables. The effects of various physical parameters on the velocity, temperature and nanoparticles fraction are incorporated through graphs. The study analyzes the efficiency of heat transfer of nanofluids in cooling plants and rubber sheets.

Originality/value

No research works have been conducted to evaluate the effects of various physical phenomena on the copper and titanium nanofluids flow.

Details

Multidiscipline Modeling in Materials and Structures, vol. 15 no. 6
Type: Research Article
ISSN: 1573-6105

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Article
Publication date: 26 November 2024

Alberto Sanchez Ramirez, Roberto D´Amato, Manuel Enrique Islán Marcos, Juan Antonio Juanes Méndez and Fernando Blaya Haro

The purpose of this paper is to characterize a new structural bi-material (scaffold and filler).

40

Abstract

Purpose

The purpose of this paper is to characterize a new structural bi-material (scaffold and filler).

Design/methodology/approach

The bi-material has been obtained by means of an additive manufacturing system consisting of a fused filament fabrication extruder head and an epoxy resin depositor head. The new bi-material will consist of a thermoplastic material that will serve as the main structure and an epoxy resin that will serve as a filler and adhesion between layers. The creation of this new bi-material will improve the physical–chemical and mechanical properties with respect to the thermoplastic material. This paper will focus on the impact behavior of IZOD and the impact behavior of punctures.

Findings

The new polylactic acid (PLA) and epoxy bi-material allow improvements in toughness and puncture impact resistance compared to the PLA thermoplastic. This increase in toughness is between 20% and 30% depending on the orientation of the print. In the same way, the energy absorbed in the puncture impact test has been increased by 42%–48%.

Practical implications

The improvement in the impact absorption capacity of this new bi-material makes it ideal for the manufacture of medical parts in which customization, lightness and impact resistance are their main characteristics such as sports protection systems.

Originality/value

The originality of creating parts through additive manufacturing that combines a material generated with cold extrusion, such as epoxy resin and a material generated with hot extrusion, such as thermoplastics, lies in the unique synergy that this mixed and simultaneous technique offers. By uniting these two manufacturing methods, it allows the exploration of new physical and chemical properties in the resulting parts, taking advantage of the individual advantages of each material. This combination opens the door to the creation of components with a wider range of characteristics, from strength and durability to flexibility and temperature resistance, thus offering innovative and versatile solutions for various applications in fields such as engineering, medicine and design.

Details

Rapid Prototyping Journal, vol. 31 no. 2
Type: Research Article
ISSN: 1355-2546

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Article
Publication date: 25 October 2021

Umair Khan, Aurang Zaib, Ioan Pop, Sakhinah Abu Bakar and Anuar Ishak

The boundary-layer analysis is required to reveal the fluid flow behavior in several industrial processes and enhance the products’ effectiveness. Therefore, this research aims to…

98

Abstract

Purpose

The boundary-layer analysis is required to reveal the fluid flow behavior in several industrial processes and enhance the products’ effectiveness. Therefore, this research aims to investigate the buoyancy or mixed convective stagnation-point flow (SPF) and heat transfer of a micropolar fluid filled with hybrid nanoparticles over a vertical plate. The nanoparticles silver (Ag) and titanium dioxide (TiO2) are scattered into various base fluids to form a new-fangled class of (Ag-TiO2/various base fluid) hybrid nanofluid along with different shape factors.

Design/methodology/approach

The self-similarity transformations are used to reformulate the leading requisite partial differential equations into renovated non-linear dimensionless ordinary differential equations. The numerical dual solutions are gained for the transmuted requisite equations with the help of the bvp4c built-in package in MATLAB software. The results are validated by comparing them with previously available published data for a particular case of the present study.

Findings

The impact of various pertaining parameters such as nanoparticle volume fraction, material parameter, shape factor and mixed convective on temperature, heat transfer, fluid motion, micro-rotation and drag force are visualized and scrutinized through tables and graphs. It is observed that dual or non-uniqueness outcomes are found for the case of buoyancy assisting flow, whereas the solution is unique in the buoyancy opposing flow case. Additionally, the fluid motion and micro-rotation profiles decelerate in the presence of nanoparticle volume fraction, while the temperature augments.

Originality/value

The mixed convective stagnation point flow conveying TiO2/Ag hybrid nanofluid with micropolar fluid with various shape factors is the significant originality of the current investigation where multiple outcomes are obtained for the assisting flow. The various base fluids such as glycerin, water and water–ethylene glycol (50%:50%) are considered in the present problem. The bifurcation values of the considered problem do not exist, probably because of various base fluids. To the best of the authors’ knowledge, this work is new and original which were not previously reported.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 32 no. 7
Type: Research Article
ISSN: 0961-5539

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