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Article
Publication date: 12 May 2022

Cheng Zhang, Jianfeng Zhou and Xiannian Meng

In the magnetorheological fluid (MRF) sealing, a large amount of friction heat is generated in the fluid film with micron thickness due to the viscosity dissipation, which…

Abstract

Purpose

In the magnetorheological fluid (MRF) sealing, a large amount of friction heat is generated in the fluid film with micron thickness due to the viscosity dissipation, which leads to seal failure and MRF deterioration. The purpose of this study is to investigate the mechanism of temperature rise of MRF film under the action of the three-field coupling of the flow field, temperature field and magnetic field.

Design/methodology/approach

The fluid film was simplified as a Couette flow in this work to simulate the temperature change in the sealing fluid film under different working conditions. The corresponding experiment for test the temperature rise was also carried out, and the temperature of the characteristic point of the stationary ring was measured to validate the model.

Findings

The results show that the temperature rise is mainly affected by the rotational speed, magnetic field strength and fluid film thickness. The magnetic field enhances the convective heat transfer in the MRF film. The thinner the fluid film, the more frictional heat generated. The MRF film reaches its maximum temperature at the contact with the end face of rotating ring due to frictional heat.

Originality/value

A method for temperature rise analysis of MRF fluid sealing films based on Couette flow is established. It is helpful for the study of liquid film frictional heat in MRF seals.

Details

Industrial Lubrication and Tribology, vol. 74 no. 6
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 6 December 2022

M.M. Bhatti, Sadiq M. Sait, R. Ellahi, Mikhail A. Sheremet and Hakan Oztop

This study aims to deal with entropy generation and thermal analysis of magnetic hybrid nanofluid containing silver and gold as nanoparticles (Au-Ag/NPs) in the…

Abstract

Purpose

This study aims to deal with entropy generation and thermal analysis of magnetic hybrid nanofluid containing silver and gold as nanoparticles (Au-Ag/NPs) in the Eyring–Powell fluid.

Design/methodology/approach

The blood is used as a base fluid to study the rheological effects in a wavy asymmetric channel. The effect of viscous dissipation is also taken into account. The mathematical model is developed using the lubrication technique. The perturbation method is used to solve the nondimensional nonlinear differential equations, whereas the pumping properties have been analyzed using numerical integration.

Findings

The impact of entropy generation, Brinkman number, Hartmann number, nanoparticles volume fraction, thermal Grashof number, Brinkman number and Eyring–Powell fluid parameter is examined on the velocity profile, temperature profile and pumping characteristics. It is observed that the introduction of gold and silver nanoparticles boosts the velocity field in a smaller segment of the channel. The temperature profile rises for the increasing values of Hartmann number, Brinkman number and nanoparticle volume fractions while the temperature profile is restrained by the Eyring–Powell fluid parameter. The pumping rate rises in all sections as the thermal Grashof number and Hartmann number increase; however, the Eyring–Powell fluid parameter has the reverse effect. The volume of the trapping boluses is significantly affected by the Eyring–Powell fluid parameter, thermal Grashof number and fluid parameter.

Originality/value

The results are original and contribute to discover the role of hybrid nanoparticles under the influence of entropy generation viscous dissipation and magnetic fields. Pharmaceutical technology may use this research for things like better mucoadhesive drug delivery systems and more productive peristaltic micropumps.

Details

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

Keywords

Article
Publication date: 21 November 2022

Nirmal K. Manna, Nirmalendu Biswas, Dipak Kumar Mandal, U.K. Sarkar, Hakan F. Öztop and Nidal Abu-Hamdeh

The study aims to assess the heater and cooler positional impacts systematically using four different quadrantal cavities filled with hybrid nanofluid, keeping the curved…

Abstract

Purpose

The study aims to assess the heater and cooler positional impacts systematically using four different quadrantal cavities filled with hybrid nanofluid, keeping the curved surface adiabatic under the orientated magnetic fields. Both heat transfer and entropy generation analyses are performed for a hybrid nanofluid flow in a quarter circular cavity considering different orientations of magnetic fields. The investigation is focused to assess the heater and cooler positional impacts systematically using four different quadrantal cavities (first to fourth quadrantal cavities), keeping the curved surface always adiabatic. The impacts of pertinent variables like Rayleigh number, Hartmann number and volumetric concentration of hybrid nanofluid on heat transfer characteristics are in consideration with the second law of thermodynamics. The analysis includes the thermal, viscous and magnetic aspects of entropy generation.

Design/methodology/approach

After validating against the experimental results, the present work explores numerically following the Galerkin weighted finite element technique. The solution is obtained through an iterative process satisfying the convergence limit of 10−8 and 10−10 for the maximum residuals and the mass defect, respectively.

Findings

It revealed that the mutual exchange of heater-cooler positions on the adjacent straight edges of the quadrant cavity does not have any impact on the flow direction. Although the magnitude of flow velocity enhances, the sidewall plays a decision-making role in the formation of a single circulation vortex. It also shows that thermal entropy production is the main cause behind thermodynamic irreversibility. The second or third quadrantal arrangement could have been opted as the best configuration of the heater-cooler position for achieving superior heat transfer. The Lorentz force plays a great role to moderate the heat transfer process. The maximum entropy generation is located, as expected, at the heating-cooling junction point.

Research limitations/implications

There are plenty of prospects for extension of the present research concept numerically or experimentally, adopting three-dimensional analysis, working fluids, boundary conditions, etc. In fact, the study could be carried out for unsteady or turbulent fluid flow.

Practical implications

As the position of the heated source and cold sink on the enclosure geometry can significantly alter the thermo-fluid phenomena, this kind of analysis is of utmost relevance for the further development of efficient heating/cooling arrangements and proper management of the devices subjected to magnetic field applications. This original contribution could be a potentially valuable source for future research and exploration pertaining to a thermal system or device, like heat exchangers, solar collectors, thermal storage, electronic cooling, food and drying technologies and others.

Originality/value

In the literature, an inadequate number of works have focused on a quadrantal cavity, mostly considering the first quadrant of the circle. However, during practical applications, it is possible that the cavity can take the shape of the other three quadrants too, and the corresponding knowledge on relative performance is still missing. Furthermore, the present investigation includes the existence of magnetic fields at various orientations. The impact analysis of this field-induced Lorentz force on the nanofluid thermal performance is another major contribution from the present work that would enrich the domain knowledge and could be useful for thermal system engineers.

Details

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

Keywords

Article
Publication date: 28 October 2022

Sheeba Juliet S., Vidhya M. and Govindarajan A.

This study aims to investigate the effect of externally applied magnetic force and heat transfer with a heat source/sink on the Couette flow with viscous dissipation in a…

Abstract

Purpose

This study aims to investigate the effect of externally applied magnetic force and heat transfer with a heat source/sink on the Couette flow with viscous dissipation in a horizontal rotating channel. The magnetic force is added to the governing equations. The effects of fluid flow parameters are observed under the applied magnetic force. In this system, the magnetic force is applied perpendicular to the plane of the fluid flow. In recent years, the magnetic field has renewed interest in aerospace technology. The physical and theoretical approach in the multidisciplinary field of magneto fluid dynamics (MFD) is applied in the field of aerospace vehicle design.

Design/methodology/approach

Authors use the perturbation method to solve and find the approximate solutions of differential equations. First, convert the partial differential equation to ordinary differential equation and calculate the approximate solutions in two cases. The first solution got by assuming heat generating in the fluid and the second one got when heat absorbing. After applying the external magnetic force, the effects of various fluid parameters velocity, temperature, skin friction coefficient and Nusselt number are found and discussed using tables and graphs.

Findings

It is found that the velocity of the fluid has decreased tendency when the rotation of the fluid and magnetic force on the fluid increases. The temperature of the fluid, Prandtl value and Eckert number increased when the heat source generated heat. When heat absorbs the heat, sink parameter increases and the temperature of the fluid decreases. Also, while heat absorbs, the temperature increases when the Prandtl value and Eckert number increase.

Originality/value

The skin friction coefficient on the surface increases, when the rotation parameter and the magnetic force parameter of the fluid increase. In the case of heat generating, the Nusselt number increased, while the Eckert number and Prandtl numbers increased. Also, the Nusselt number has larger values when the heat source parameter has near the constant temperature, and it has smaller values when the temperature varies. In the case of heat-absorbing, the Nusselt number decreased when the Eckert and Prandtl numbers increased. Also, the Nusselt number varies up and down while the heat absorbing parameter increases.

Details

Aircraft Engineering and Aerospace Technology, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1748-8842

Keywords

Article
Publication date: 1 November 2022

Yongliang Wang and Xin Zhang

Hydrofracturing technology has been widely used in tight oil and gas reservoir exploitation, and the fracture network formed by fracturing is crucial to determining the…

Abstract

Purpose

Hydrofracturing technology has been widely used in tight oil and gas reservoir exploitation, and the fracture network formed by fracturing is crucial to determining the resources recovery rate. Due to the complexity of fracture network induced by the random morphology and type of fluid-driven fractures, controlling and optimising its mechanisms is challenging. This paper aims to study the types of multiscale mode I/II fractures, the fluid-driven propagation of multiscale tensile and shear fractures need to be studied.

Design/methodology/approach

A dual bilinear cohesive zone model (CZM) based on energy evolution was introduced to detect the initiation and propagation of fluid-driven tensile and shear fractures. The model overcomes the limitations of classical linear fracture mechanics, such as the stress singularity at the fracture tip, and considers the important role of fracture surface behaviour in the shear activation. The bilinear cohesive criterion based on the energy evolution criterion can reflect the formation mechanism of complex fracture networks objectively and accurately. Considering the hydro-mechanical (HM) coupling and leak-off effects, the combined finite element-discrete element-finite volume approach was introduced and implemented successfully, and the results showed that the models considering HM coupling and leak-off effects could form a more complex fracture network. The multiscale (laboratory- and engineering-scale) Mode I/II fractures can be simulated in hydrofracturing process.

Findings

Based on the proposed method, the accuracy and applicability of the algorithm were verified by comparing the analytical solution of KGD and PKN models. The effects of different in situ stresses and flow rates on the dynamic propagation of hydraulic fractures at laboratory and engineering scales were investigated. when the ratio of in situ stress is small, the fracture propagation direction is not affected, and the fracture morphology is a cross-type fracture. When the ratio of in situ stress is relatively large, the propagation direction of the fracture is affected by the maximum in situ stress, and it is more inclined to propagate along the direction of the maximum in situ stress, forming double wing-type fractures. Hydrofracturing tensile and shear fractures were identified, and the distribution and number of each type were obtained. There are fewer hydraulic shear fractures than tensile fractures, and shear fractures appear in the initial stage of fracture propagation and then propagate and distribute around the perforation.

Originality/value

The proposed dual bilinear CZM is effective for simulating the types of Mode I/II fractures and seizing the fluid-driven propagation of multiscale tensile and shear fractures. Practical fracturing process involves the multi-type and multiscale fluid-driven fracture propagation. This study introduces general fluid-driven fracture propagation, which can be extended to the fracture propagation analysis of potential fluid fracturing, such as other liquids or supercritical gases.

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…

1108

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

Keywords

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

Keywords

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.

1648

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

Keywords

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

Keywords

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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