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Article
Publication date: 25 March 2024

Emrehan Gürsoy, Hayati Kadir Pazarlioğlu, Mehmet Gürdal, Engin Gedik, Kamil Arslan and Abdullah Dağdeviren

The purpose of this study is to analyse the magnetic field effect on Fe3O4/H2O Ferrofluid flowing in a sudden expansion tube, which has specific behaviour in terms of rheology…

Abstract

Purpose

The purpose of this study is to analyse the magnetic field effect on Fe3O4/H2O Ferrofluid flowing in a sudden expansion tube, which has specific behaviour in terms of rheology, with convex dimple fins. Because the investigation of flow separation is a prominent application in performance, the effect of magnetic field and convex dimple on the thermo-hydraulic performance of sudden expansion tube are examined, in detail.

Design/methodology/approach

During the solution of the boundary conditions of the sudden expansion tube, finite volume method was used. Analyses have been conducted considering the single-phase solution, steady-state, incompressible fluid and no-slip condition of the wall under forced convection conditions. In the analyses, it has been assumed that the flow was developing thermally and has been fully developed hydrodynamically.

Findings

The present study focuses on exploring the influence of the magnetic field, nanofluid concentration and convex dimple fins on the thermo-hydraulic performance of sudden expansion tube. The results indicate that the strength of the magnetic field, nanofluid concentration and convex dimple fins have a positive effect on the convective heat transfer in the system.

Originality/value

The authors conducted numerical studies, determining through a literature search that no one had yet investigated enhancing heat transfer on a sudden expansion tube using combinations of magnetic fields, nanofluids and convex dimple fins. The results of the numerical analyses provide valuable information about the improvement of heat transfer and system performance in electronic device cooling and heat exchangers.

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: 25 December 2023

Fatima Harbate, Nouh Izem, Mohammed Seaid and Dia Zeidan

The purpose of this paper is to investigate the two-phase flow problems involving gas–liquid mixture.

Abstract

Purpose

The purpose of this paper is to investigate the two-phase flow problems involving gas–liquid mixture.

Design/methodology/approach

The governed equations consist of a range of conservation laws modeling a classification of two-phase flow phenomena subjected to a velocity nonequilibrium for the gas–liquid mixture. Effects of the relative velocity are accounted for in the present model by a kinetic constitutive relation coupled to a collection of specific equations governing mass and volume fractions for the gas phase. Unlike many two-phase models, the considered system is fully hyperbolic and fully conservative. The suggested relaxation approach switches a nonlinear hyperbolic system into a semilinear model that includes a source relaxation term and characteristic linear properties. Notably, this model can be solved numerically without the use of Riemann solvers or linear iterations. For accurate time integration, a high-resolution spatial reconstruction and a Runge–Kutta scheme with decreasing total variation are used to discretize the relaxation system.

Findings

The method is used in addressing various nonequilibrium two-phase flow problems, accompanied by a comparative study of different reconstructions. The numerical results demonstrate the suggested relaxation method’s high-resolution capabilities, affirming its proficiency in delivering accurate simulations for flow regimes characterized by strong shocks.

Originality/value

While relaxation methods exhibit notable performance and competitive features, as far as we are aware, there has been no endeavor to address nonequilibrium two-phase flow problems using these methods.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 34 no. 3
Type: Research Article
ISSN: 0961-5539

Keywords

Case study
Publication date: 8 January 2024

Aasha Jayant Sharma

Upon completion of the case study, the students will be able to apply business upscaling strategies to an upcycling social enterprise that is embracing a circular economy approach…

Abstract

Learning outcomes

Upon completion of the case study, the students will be able to apply business upscaling strategies to an upcycling social enterprise that is embracing a circular economy approach by using the Ansoff growth matrix; to analyze strategies for transition to circularity using the butterfly diagram tool for both business and personal use; to indulge in upcycling exercises for a used product of their choice, not only unleashing their creative potential but also contributing to an idea that might get them to win a contest; to analyze different operational problems and efficiency opportunities that arise when a company takes on social and environmental causes as a business opportunity; and to strategize how a social enterprise can be sustained and made for-profit by applying business strategies.

Case overview/synopsis

This case study covers the concepts of upcycling under the gamut of circular economy, a concept that has become more of a strategy to sustain and survive in today’s world. This case is about Rimagined, an upcycling company that could be a model for circular ideas and upcycling of stuff. This case study narrates the growth and the challenges faced in upcycling and encourages students to ideate a new design for any upcycling item of their choice. This case will also make students strategize the expansion plan for Rimagined. Shailaja Rangarajan is the protagonist of this case study who started this social enterprise to make a difference and do her bit. Sustaining a social enterprise requires business acumen and risk-bearing capacities like any other business. Rangarajan was facing the dilemma of expansion and was trying out several feasible options. Rimagined had been unable to attract investors because their expectations of quick returns could not be immediately fulfilled. Investors focused more on waste management as an industry and not on upcycling as a separate area of work.

Complexity academic level

This case study is suitable for students of MBA or executive MBA level. Specifically, this case study can be used in business strategies and circular economy courses.

Supplementary materials

Teaching notes are available for educators only.

Subject code

CSS 4: Environmental management.

Details

Emerald Emerging Markets Case Studies, vol. 14 no. 1
Type: Case Study
ISSN: 2045-0621

Keywords

Article
Publication date: 28 March 2024

Zhong Jin, Xiang Li, Feng He, Fangting Liu, Jinyu Li and Junhui Li

The performance of oil-filled pressure cores is very much affected by the corrugated diaphragm and the oil filling volume. The purpose of this paper is to show the effects of…

Abstract

Purpose

The performance of oil-filled pressure cores is very much affected by the corrugated diaphragm and the oil filling volume. The purpose of this paper is to show the effects of different corrugated diaphragms, different oil filling volumes and different treatments of the corrugated diaphragms on the performance of pressure sensors.

Design/methodology/approach

Pressure-sensitive cores with different diaphragm diameters, different diaphragm ripple numbers and different oil filling volumes are produced, and thermal cycling is introduced to improve the diaphragm performance, and finally the performance of each pressure-sensitive core is tested and the test data are analyzed and compared.

Findings

The experimental results show that the larger the diameter of the corrugated diaphragm used for encapsulation, the better the performance. For pressure-sensitive cores using smaller diameter corrugated diaphragms, the performance of one corrugation is better than that of two corrugations. When the number of corrugations and the diameter are the same size, the performance of the outer ring of the diaphragm with concave corrugations is better than that with convex corrugations. At the same time, the diaphragm after thermal cycling treatment and appropriate reduction of encapsulated oil filling can improve the performance of the pressure-sensitive core.

Originality/value

By exploring the effects of corrugated diaphragm and oil filling volume on the performance of oil-filled pressure cores, the design of oil-filled pressure sensors can be guided to improve sensor performance.

Details

Sensor Review, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0260-2288

Keywords

Open Access
Article
Publication date: 8 November 2023

Armando Di Meglio, Nicola Massarotti, Samuel Rolland and Perumal Nithiarasu

This study aims to analyse the non-linear losses of a porous media (stack) composed by parallel plates and inserted in a resonator tube in oscillatory flows by proposing numerical…

Abstract

Purpose

This study aims to analyse the non-linear losses of a porous media (stack) composed by parallel plates and inserted in a resonator tube in oscillatory flows by proposing numerical correlations between pressure gradient and velocity.

Design/methodology/approach

The numerical correlations origin from computational fluid dynamics simulations, conducted at the microscopic scale, in which three fluid channels representing the porous media are taken into account. More specifically, for a specific frequency and stack porosity, the oscillating pressure input is varied, and the velocity and the pressure-drop are post-processed in the frequency domain (Fast Fourier Transform analysis).

Findings

It emerges that the viscous component of pressure drop follows a quadratic trend with respect to velocity inside the stack, while the inertial component is linear also at high-velocity regimes. Furthermore, the non-linear coefficient b of the correlation ax + bx2 (related to the Forchheimer coefficient) is discovered to be dependent on frequency. The largest value of the b is found at low frequencies as the fluid particle displacement is comparable to the stack length. Furthermore, the lower the porosity the higher the Forchheimer term because the velocity gradients at the stack geometrical discontinuities are more pronounced.

Originality/value

The main novelty of this work is that, for the first time, non-linear losses of a parallel plate stack are investigated from a macroscopic point of view and summarised into a non-linear correlation, similar to the steady-state and well-known Darcy–Forchheimer law. The main difference is that it considers the frequency dependence of both Darcy and Forchheimer terms. The results can be used to enhance the analysis and design of thermoacoustic devices, which use the kind of stacks studied in the present work.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 34 no. 1
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 9 November 2022

Merve Cerrahoğlu and Feray Maden

The most important need after natural disasters is the sheltering. However, most of the existing temporary shelters do not meet all requirements for long-term use and not provide…

Abstract

Purpose

The most important need after natural disasters is the sheltering. However, most of the existing temporary shelters do not meet all requirements for long-term use and not provide adequate flexibility within the space. This paper aims to develop a transitional postdisaster shelter transforming from a closed shape to an expanded form in response to changing functional and spatial needs of disaster victims. The study also proposes alternative unit combinations for various functions, and settlement layouts to create a comfortable living environment for occupants.

Design/methodology/approach

The research methodology is based on theoretical and design frameworks which requires inductive and deductive approaches. Forming the background of the study, the theoretical framework consists of four parts which are literature review on temporary shelters presenting state-of-the-art; determination of design guidelines and strategies based on shelter standards; identification of technical requirements; and analysis of existing temporary shelters. Having three parts, the design framework includes design of transformable transitional shelter based on three-dimensional modeling, creation of different unit combinations to be used for various purposes and development of settlement layouts as case studies.

Findings

The analysis conducted in this study demonstrates that most of the existing temporary shelters have limited geometric configurations and major problems in terms of their performance, transportation and storage. On the other hand, the transformable shelter proposed by the authors can provide form and spatial flexibilities thanks to its expansion properties, occupy less space for transportation, easily be transported to any desired location in its compact state and be customized according to user needs. Several units can be combined either to serve larger families or to be used for different functions.

Originality/value

This paper contributes to the literature as presenting not only a theoretical framework on temporary shelters but also a design framework on transformable shelter design for the ones who are willing to develop similar transformable shelters based on the determined guidelines, strategies and requirements.

Details

International Journal of Disaster Resilience in the Built Environment, vol. 15 no. 2
Type: Research Article
ISSN: 1759-5908

Keywords

Article
Publication date: 1 December 2022

Naveenkumar R., Shanmugam S. and Veerappan AR

The purpose of this paper is to understand the effect of basin water depth towards the cumulative distillate yield of the traditional and developed single basin double slope solar…

Abstract

Purpose

The purpose of this paper is to understand the effect of basin water depth towards the cumulative distillate yield of the traditional and developed single basin double slope solar still (DSSS).

Design/methodology/approach

Modified single basin DSSS integrated with solar operated vacuum fan and external water cooled condenser was fabricated using aluminium material. During sunny season, experimental investigations have been performed in both conventional and modified DSSS at a basin water depth of 3, 6, 9 and 12 cm. Production rate and cumulative distillate yield obtained in traditional and developed DSSS at different water depths were compared and best water depth to attain the maximum productivity and cumulative distillate yield was found out.

Findings

Results indicated that both traditional and modified double SS produced maximum yield at the minimum water depth of 3 cm. Cumulative distillate yield of the developed SS was 16.39%, 18.86%, 15.22% and 17.07% higher than traditional at water depths of 3, 6, 9 and 12 cm, respectively. Cumulative distillate yield of the developed SS at 3 cm water depth was 73.17% higher than that of the traditional SS at 12 cm depth.

Originality/value

Performance evaluation of DSSS at various water depths by integrating the combined solar operated Vacuum fan and external Condenser.

Details

World Journal of Engineering, vol. 21 no. 2
Type: Research Article
ISSN: 1708-5284

Keywords

Article
Publication date: 5 January 2024

Fateh Mebarek-Oudina, Ines Chabani, Hanumesh Vaidya and Abdul Aziz I. Ismail

This paper aims to present a numerical study that investigates the flow of MgO-Al2O3/water hybrid nanofluid inside a porous elliptical-shaped cavity, in which we aim to examine…

Abstract

Purpose

This paper aims to present a numerical study that investigates the flow of MgO-Al2O3/water hybrid nanofluid inside a porous elliptical-shaped cavity, in which we aim to examine the performance of this thermal system when exposed to a magnetic field via heat transfer features and entropy generation.

Design/methodology/approach

The configuration consists of the hybrid nanofluid out layered by a cold ellipse while it surrounds a non-square heated obstacle; the thermal structure is under the influence of a horizontal magnetic field. This problem is implemented in COMSOL multiphysics, which solves the related equations described by the “Darcy-Forchheimer-Brinkman” model through the finite element method.

Findings

The results illustrated as streamlines, isotherms and average Nusselt number, along with the entropy production, are given as functions of: the volume fraction, and shape factor to assess the behaviour of the properties of the nanoparticles. Darcy number and porosity to designate the impact of the porous features of the enclosure, and finally the strength of the magnetic induction described as Hartmann number. The outcomes show the increased pattern of the thermal and dynamical behaviour of the hybrid nanofluid when augmenting the concentration, shape factor, porosity and Darcy number; however, it also engenders increased formations of irreversibilities in the system that were revealed to enhance with the permeability and the great properties of the nanofluid. Nevertheless, this thermal enhanced pattern is shown to degrade with strong Hartmann values, which also reduced both thermal and viscous entropies. Therefore, it is advised to minimize the magnetic influence to promote better heat exchange.

Originality/value

The investigation of irreversibilities in nanofluids heat transfer is an important topic of research with practical implications for the design and optimization of heat transfer systems. The study’s findings can help improve the performance and efficiency of these systems, as well as contribute to the development of sustainable energy technologies. The study also offers an intriguing approach that evaluates entropy growth in this unusual configuration with several parameters, which has the potential to transform our understanding of complicated fluid dynamics and thermodynamic processes, and at the end obtain the best thermal configuration possible.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 34 no. 2
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 27 September 2022

Chafika Ali Ahmed, Abdelmadjid Si Salem, Souad Ait Taleb and Kamal Ait Tahar

This paper aims to investigate the experimental behavior and the reliability of concrete columns repaired using fiber-reinforced polymers (FRPs) under axial compression loading…

Abstract

Purpose

This paper aims to investigate the experimental behavior and the reliability of concrete columns repaired using fiber-reinforced polymers (FRPs) under axial compression loading. The expression of the ultimate axial resistance was assessed from the experimental data of damaged concrete cylinders repaired by externally bonded double-FRP spiral strips.

Design/methodology/approach

The tested columns bearing capacity mainly depends of the elasticity modulus of both damaged and undamaged concrete have been considered in addition to the applied load and the cylinder diameter as random variables in the expression of the failure criterion. The reliability indicators were assessed using first order second moment method.

Findings

The emphasized test results, statistically fitted show that the strength has been retrofitted for all repaired specimens whatever the degree of initial damage. However, the gain in axial strength is inversely proportional to the degree of damage.

Originality/value

The efficiency of a new FRP repair procedure using double-spiral strips was studied. This research provides a technical and economical solution for retrofitting existing concrete columns. Finally, the random character of the variables that govern the studied system shows the accuracy and safety of the proposed original design.

Details

World Journal of Engineering, vol. 21 no. 1
Type: Research Article
ISSN: 1708-5284

Keywords

Article
Publication date: 31 July 2023

Safia Akram, Maria Athar, Khalid Saeed, Mir Yasir Umair and Taseer Muhammad

The purpose of this study, thermal radiation and viscous dissipation impacts on double diffusive convection on peristaltic transport of Williamson nanofluid due to induced…

Abstract

Purpose

The purpose of this study, thermal radiation and viscous dissipation impacts on double diffusive convection on peristaltic transport of Williamson nanofluid due to induced magnetic field in a tapered channel is examined. The study of propulsion system is on the rise in aerospace research. In spacecraft technology, the propulsion system uses high-temperature heat transmission governed through thermal radiation process. This study will help in assessment of chyme movement in the gastrointestinal tract and also in regulating the intensity of magnetic field of the blood flow during surgery.

Design/methodology/approach

The brief mathematical modelling, along with induced magnetic field, of Williamson nanofluid is given. The governing equations are reduced to dimensionless form by using appropriate transformations. Numerical technique is manipulated to solve the highly nonlinear differential equations. The roll of different variables is graphically analyzed in terms of concentration, temperature, volume fraction of nanoparticles, axial-induced magnetic field, magnetic force function, stream functions, pressure rise and pressure gradient.

Findings

The key finding from the analysis above can be summed up as follows: the temperature profile decreases and concentration profile increases due to the rising impact of thermal radiation. Brownian motion parameter has a reducing influence on nanoparticle concentration due to massive transfer of nanoparticles from a hot zone to a cool region, which causes a decrease in concentration profile· The pressure rise enhances due to rising values of thermophoresis and thermal Grashof number in retrograde pumping, free pumping and copumping region.

Originality/value

To the best of the authors’ knowledge, a study that integrates double-diffusion convection with thermal radiation, viscous dissipation and induced magnetic field on peristaltic flow of Williamson nanofluid with a channel that is asymmetric has not been carried out so far.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 34 no. 2
Type: Research Article
ISSN: 0961-5539

Keywords

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