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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…

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. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0961-5539

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Article
Publication date: 8 September 2021

S. Das, A.S. Banu and R.N. Jana

In various kinds of materials processes, heat and mass transfer control in nuclear phenomena, constructing buildings, turbines and electronic circuits, etc., there are…

Abstract

Purpose

In various kinds of materials processes, heat and mass transfer control in nuclear phenomena, constructing buildings, turbines and electronic circuits, etc., there are numerous problems that cannot be enlightened by uniform wall temperature. To explore such physical phenomena researchers incorporate non-uniform or ramped temperature conditions at the boundary, the purpose of this paper is to achieve the closed-form solution of a time-dependent magnetohydrodynamic (MHD) boundary layer flow with heat and mass transfer of an electrically conducting non-Newtonian Casson fluid toward an infinite vertical plate subject to the ramped temperature and concentration (RTC). The consequences of chemical reaction in the mass equation and thermal radiation in the energy equation are encompassed in this analysis. The flow regime manifests with pertinent physical impacts of the magnetic field, thermal radiation, chemical reaction and heat generation/absorption. A first-order chemical reaction that is proportional to the concentration itself directly is assumed. The Rosseland approximation is adopted to describe the radiative heat flux in the energy equation.

Design/methodology/approach

The problem is formulated in terms of partial differential equations with the appropriate physical initial and boundary conditions. To make the governing equations dimensionless, some suitable non-dimensional variables are introduced. The resulting non-dimensional equations are solved analytically by applying the Laplace transform method. The mathematical expressions for skin friction, Nusselt number and Sherwood number are calculated and expressed in closed form. Impacts of various associated physical parameters on the pertinent flow quantities, namely, velocity, temperature and concentration profiles, skin friction, Nusselt number and Sherwood number, are demonstrated and analyzed via graphs and tables.

Findings

Graphical analysis reveals that the boundary layer flow and heat and mass transfer attributes are significantly varied for the embedded physical parameters in the case of constant temperature and concentration (CTC) as compared to RTC. It is worthy to note that the fluid velocity is high with CTC and lower for RTC. Also, the fluid velocity declines with the augmentation of the magnetic parameter. Moreover, growth in thermal radiation leads to a declination in the temperature profile.

Practical implications

The proposed model has relevance in numerous engineering and technical procedures including industries related to polymers, area of chemical productions, nuclear energy, electronics and aerodynamics. Encouraged by such applications, the present work is undertaken.

Originality/value

Literature review unveils that sundry studies have been carried out in the presence of uniform wall temperature. Few studies have been conducted by considering non-uniform or ramped wall temperature and concentration. The authors are focused on an analytical investigation of an unsteady MHD boundary layer flow with heat and mass transfer of non-Newtonian Casson fluid past a moving plate subject to the RTC at the plate. Based on the authors’ knowledge, the present study has, so far, not appeared in scientific communications. Obtained analytical solutions are verified by considering particular cases of the published works.

Details

World Journal of Engineering, vol. 18 no. 5
Type: Research Article
ISSN: 1708-5284

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Article
Publication date: 13 September 2021

Gholamreza Imani and Mohsen Mozafari-Shamsi

The lattice Boltzmann simulation of fluid flow in partial porous geometries with curved porous-fluid interfaces has not been investigated yet. It is mainly because of the…

Abstract

Purpose

The lattice Boltzmann simulation of fluid flow in partial porous geometries with curved porous-fluid interfaces has not been investigated yet. It is mainly because of the lack of a method in the lattice Boltzmann framework to model the hydrodynamic compatibility conditions at curved porous-fluid interfaces, which is required for the two-domain approach. Therefore, the purpose of this study is to develop such a method.

Design/methodology/approach

This research extends the non-equilibrium extrapolation lattice Boltzmann method for satisfying no-slip conditions at curved solid boundaries, to model hydrodynamic compatibility conditions at curved porous-fluid interfaces.

Findings

The proposed method is tested against the results available from conventional numerical methods via the problem of fluid flow through and around a porous circular cylinder in crossflow. As such, streamlines, geometrical characteristics of recirculating wakes and drag coefficient are validated for different Reynolds (5 ≤ Re ≤ 40) and Darcy (10−5Da ≤ 5 × 10−1) numbers. It is also shown that without applying any compatibility conditions at the interface, the predicted flow structure is not satisfactory, even for a very fine mesh. This result highlights the importance of the two-domain approach for lattice Boltzmann simulation of the fluid flow in partial porous geometries with curved porous-fluid interfaces.

Originality/value

No research is found in the literature for applying the hydrodynamic compatibility conditions at curved porous-fluid interfaces in the lattice Boltzmann framework.

Details

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

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Article
Publication date: 23 September 2021

Najiyah Safwa Khashi'ie, Iskandar Waini, Syazwani Mohd Zokri, Abdul Rahman Mohd Kasim, Norihan Md Arifin and Ioan Pop

This paper aims to accentuate the behavior of second-grade hybrid Al2O3–Cu nanofluid flow and its thermal characteristics driven by a stretching/shrinking Riga plate.

Abstract

Purpose

This paper aims to accentuate the behavior of second-grade hybrid Al2O3–Cu nanofluid flow and its thermal characteristics driven by a stretching/shrinking Riga plate.

Design/methodology/approach

The second-grade fluid is considered with the combination of Cu and Al2O3 nanoparticles. Three base fluids namely water, ethylene glycol (EG) and methanol with different Prandtl number are also examined. The formulation of the mathematical model of second-grade hybrid nanofluid complies with the boundary layer approximations. The complexity of the governing model is reduced into a simpler differential equations using the similarity transformation. The bvp4c solver is fully used to solve the reduced equations. The observation of multiple solutions is conducted for the assisting (stretching) and opposing (shrinking) cases.

Findings

The impact of suction parameter, second-grade parameter, electromagnetohydrodynamics (EMHD) parameter, velocity ratio parameter and the volumetric concentration of the alumina and copper nanoparticles are numerically analyzed on the velocity and temperature profiles, skin friction coefficient and local Nusselt number (thermal rate) of the second-grade Al2O3–Cu/water. The solution is unique when (static and stretching cases) while dual for a specific range of negative in the presence of suction effect. Based on the appearance of the first solution in all cases of, it is physically showed that the first solution is stable. Further examination reveals that the EMHD and suction parameters are the contributing factors for the thermal enhancement of this non-Newtonian working fluid. Meanwhile, the viscosity of the non-Newtonian fluid also plays a significant role in the fluid motion and heat transfer rate based on the finding that the EG base fluid produces the maximum heat transfer rate but the lowest critical value and skin friction coefficient.

Originality/value

The results are novel and contribute to the discovery of the hybrid nanoparticles’ performance in the non-Newtonian second-grade fluid. Besides, this study is beneficial to the researchers in this field and general audience from industries regarding the factors, which contributing to the thermal enhancement of the working fluid.

Details

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

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Article
Publication date: 1 September 2006

O.C. Mendes, R.F. Ávila, A.M. Abrão, Pedro Reis and J. Paulo Davim

The knowledge over the performance of cutting fluids when applied under different machining conditions (such as distinct work material and cutting parameters) is critical…

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1091

Abstract

Purpose

The knowledge over the performance of cutting fluids when applied under different machining conditions (such as distinct work material and cutting parameters) is critical in order to improve the efficiency of most machining operations. This paper is concerned with the performance of cutting fluids employed under two distinct machining operations involving aluminium alloys: drilling of AA 1050‐O aluminium applying cutting fluid as a mist and turning of AA 6262‐T6 aluminium alloy using cutting fluids (as a flood) with distinct extreme pressure additives (chlorine, sulphur and phosphor).

Design/methodology/approach

This work reports on a experimental study of the performance of cutting fluids when machining aluminium alloys.

Findings

The results indicated an increase in the flow rate of the mist led to lower feed forces but higher torque, power consumption and specific cutting pressure in the drilling operation (AA 1050‐O aluminium). The surface finish was not drastically affected by the cutting fluid flow rate. When turning AA 6162‐T6 aluminium alloy, in general, best results were observed using 10 per cent fluid concentration applied at the tool‐workpiece interface. The cutting fluid containing chlorine as extreme pressure additive produced lower cutting forces and better surface finish at high cutting speed and low feed rate and depth of cut.

Originality/value

The novel element of this paper is the use of minimal lubrication (drilling) and cutting fluids with distinct extreme pressure (turning).

Details

Industrial Lubrication and Tribology, vol. 58 no. 5
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 4 September 2017

Lijesh K.P., Deepak Kumar and Harish Hirani

The purpose of this paper is to report on the development of magnetorheological (MR) fluids, having high on-state shear stress/viscosity, low off-state shear…

Abstract

Purpose

The purpose of this paper is to report on the development of magnetorheological (MR) fluids, having high on-state shear stress/viscosity, low off-state shear stress/viscosity, good redispersibility and stable suspension of carbonyl iron particles, using tetramethyl ammonium hydroxide (TAH) and oleic acid.

Design/methodology/approach

MR fluids for use in brakes are synthesized using different weight percentages of silicone oil, TAH, oleic acid and iron particles. The effects of TAH and oleic acid are studied. Shear stress is measured as a function of magnetic field on a magneto-rheometer. The images of MR particles settling with time are presented. The test set-up used to evaluate the performance of the MR fluids synthesized for brake application is detailed. Finally, a significant improvement in the MR performance of brakes is reported.

Findings

The MR fluid having 0.25 Wt.% oleic acid showed low off-state viscosity/shear stress and high on-state viscosity/shear stress. A higher weight percentage of TAH in the MR fluid further reduced the low off-shear stress and increased the high on-state shear stress with better stability.

Originality/value

Improvement of MR brake performance by adding surfactants like TAH and oleic acid has been the subject matter of several studies in the past, but these studies used a fixed percentage of surfactants in MR fluids. In the present work, the optimum percentage of TAH and oleic acid for an improved braking performance is determined by varying their content in the MR fluid, which has not been reported in any other work thus far.

Details

Industrial Lubrication and Tribology, vol. 69 no. 5
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 1 June 2005

Wlodzimierz Ochonski

To present some new designs of magnetic fluid exclusion seals for rolling bearings and possibility to use them in modern industrial sealing applications.

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1618

Abstract

Purpose

To present some new designs of magnetic fluid exclusion seals for rolling bearings and possibility to use them in modern industrial sealing applications.

Design/methodology/approach

In the paper is given principle of magnetic fluid sealing technology and are presented new designs of magnetic fluid exclusion seals for rolling bearings, such as compact magnetic fluid seals, two‐stages seals being combination of magnetic fluid seal and labyrinth seal or radial lip seal, magnetic fluid seals with “floating” magnetic system. This paper also shows examples of their application in various rotating process equipment.

Findings

Provides information about new designs of bearing seals and gives the main advantages of these seals over other types, such as total tightness, low viscous drag, maintenance‐free service and high reliability.

Originality/value

This paper offers some new designs of high‐performance magnetic fluid exclusion seals for rolling bearings and points their practical applications.

Details

Industrial Lubrication and Tribology, vol. 57 no. 3
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 9 May 2008

M.A. Nazarboland, X. Chen, J.W.S. Hearle, R. Lydon and M. Moss

This paper aims to discuss the development of a software tool UniverFilter™ which is capable of geometrical modelling of 3D woven fabrics, interfacing with computational…

Abstract

Purpose

This paper aims to discuss the development of a software tool UniverFilter™ which is capable of geometrical modelling of 3D woven fabrics, interfacing with computational fluid dynamics tools to numerically determine the fluid (and more specifically liquid) flow path and simulating the filtration process by introducing particles of various shapes and sizes.

Design/methodology/approach

The method employed in creating the software tool is based on geometrical modelling of the single‐layer woven fabric with monofilament yarns, numerical analysis of the fluid‐flow problem, and mathematical modelling of the forces exerted on particles to accurately predict the settlement of such particles on the fabric. In the case of particle motion, a Lagrangian approach is used.

Findings

Creation of a software tool capable of simulation and modelling the filtration process through woven fabrics is the primary achievement. The effect of geometrical parameters of the woven fabric on fluid flow utilizing the results from fluid pressure and fluid velocity on the fabric show that the fluid flow is significantly influenced in the interstices and chamber downstream by the fabric. Fluid‐flow resistance and pressure loss are obtained from the results of fluid velocity and pressure. The results from the fluid pressure on the fabric could also be employed to more accurately predict how pore shapes and sizes are transformed.

Originality/value

Creation of a modelling tool for filtration through woven fabric media. This software is the foundation of establishing a standalone tool with the capability to design, test and improve fabric filter design for more efficient filtration properties.

Details

International Journal of Clothing Science and Technology, vol. 20 no. 3
Type: Research Article
ISSN: 0955-6222

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Article
Publication date: 1 April 1985

Lorraine G. Olson and Klaus‐Jürgen Bathe

An infinite element based on the doubly asymptotic approximation (DAA) for use in finite element analysis of fluid—structure interactions is presented. Fluid finite…

Abstract

An infinite element based on the doubly asymptotic approximation (DAA) for use in finite element analysis of fluid—structure interactions is presented. Fluid finite elements model the region near the solid. Infinite elements account for the effects of the outer fluid on the inner region. The DAA‐based infinite elements involve an approximate calculation of the added mass using static mapped infinite elements, plus a consistent damping term. Simple test analyses for a range of fluid properties demonstrate the performance of the solution technique. The analyses of a Helmholtz resonator (open pipe) and a circular plate in water indicate the practical use of the solution approach.

Details

Engineering Computations, vol. 2 no. 4
Type: Research Article
ISSN: 0264-4401

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Article
Publication date: 16 January 2007

M.A. Mehrabian and M. Khoramabadi

The purpose of this paper is to investigate numerically the influence of variable fluid viscosity on thermal characteristics of plate heat exchangers for counter‐flow and…

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1312

Abstract

Purpose

The purpose of this paper is to investigate numerically the influence of variable fluid viscosity on thermal characteristics of plate heat exchangers for counter‐flow and steady‐state conditions.

Design/methodology/approach

The approach to fulfill the purpose of the paper is to derive the one‐dimensional energy balance equations for the cold and hot streams in the adjacent channels of a plate heat exchange composed of four corrugated plates. A finite difference method has been used to calculate the temperature distribution and thermal performance of the exchanger. Water is used as the hot liquid being cooled in the side channels, while a number of working fluids whose viscosity variation versus temperature is more severe were used as the cold fluid being heated in the central channel.

Findings

The program is run for a combination of working fluids such as water‐water, water‐isooctane, water‐benzene, water‐glycerin and water‐gasoline. The temperature distributions of both streams have been plotted along the flow channel for all the above combination of working fluids. The overall heat transfer coefficients have also been plotted against both cold and hot fluid temperatures. It is found that the overall heat transfer coefficient varies linearly with respect to either cold or hot fluid temperature within the temperature ranges applied in the paper. The exchanger effectiveness is not significantly affected when either the temperature dependent viscosity is applied or the nature of cold liquid is changed.

Originality/value

This paper contains a new method of numerical solution of energy balance equations for the thermal control volumes bounded by two plates. A comparison of the calculated results with documented experimental results validates the numerical method.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 17 no. 1
Type: Research Article
ISSN: 0961-5539

Keywords

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