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Article
Publication date: 23 May 2022

Syed Saqib Shah, Hakan F. Öztop, Rizwan Ul-Haq and Nidal Abu-Hamdeh

The purpose of this paper is to analyse the buoyancy flow, mass and heat transfer in coaxial duct under Soret and Dufour effect. The combined effects of the…

Abstract

Purpose

The purpose of this paper is to analyse the buoyancy flow, mass and heat transfer in coaxial duct under Soret and Dufour effect. The combined effects of the thermal-diffusion and diffusion-thermo coefficients, as well as the Schmidt number, on natural convection in a heated lower coaxial curve were explored using the proposed physical model. The Dufour and Soret effects are taken into consideration in the energy and concentration equations, respectively.

Design/methodology/approach

The dominating mathematical models are converted into a set of non-linear coupled partial differential equations, which are solved using a numerical approach. The controlling non-linear boundary value problem is numerically solved using the penalty finite element method with Galerkin’s weighted residual scheme over the entire variety of essential parameters.

Findings

It was observed that different parameters were tested such as heat generation or absorption coefficient, buoyancy ratio, Soret coefficient, Dufour coefficient, Lewis number and Rayleigh number. Effect of Rayleigh number, absorption/generation and Dufour coefficient on isotherm are significantly reported. For greater values of Lewis number, maximum mass transfer in duct in the form of molecular particles is produced. Buoyancy ratio parameter decreases the average rate of heat flow and increases its mass transfer.

Originality/value

The main originality of this work is to make an application of Soret and Dufour effects in a coaxial duct in the presence of source sink.

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: 23 November 2020

Muhammad Usman, Muhammad Hamid, Zafar Hayat Khan, Rizwan Ul Haq and Waqar Ahmed Khan

This study aims to deal with the numerical investigation of ferrofluid flow and heat transfer inside a right-angle triangular cavity in the presence of a magnetic field…

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Abstract

Purpose

This study aims to deal with the numerical investigation of ferrofluid flow and heat transfer inside a right-angle triangular cavity in the presence of a magnetic field. The vertical wall is partially heated, whereas other walls are kept cold. The effects of thermal radiation are included in the analysis. The governing equations including continuity, momentum and energy equations are converted to nondimensional form using viable variables.

Design/methodology/approach

Finite element method (FEM)-based simulations are performed using finite element approach to investigate the effects of the volume fraction of ferroparticles (Fe3O4), the length of the heating element and the dimensionless numbers including Rayleigh and Hartmann numbers on the streamlines, isotherms and Nusselt number.

Findings

It is demonstrated that both horizontal and vertical velocity components increase with the length of the heating element, whereas the dimensionless temperature decreases the heating domain. It is observed that an increase of 10% in the volume fraction of ferroparticles increases Nusselt number more than 12%, and 20% increase in the volume fraction of ferroparticles increases more than 30%, depending upon the length of the heating element.

Originality/value

This is a new study showing the significance of the magnetic nanoparticles for the enhancement of heat transfer rate in a triangular cavity.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 31 no. 10
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 6 November 2018

Aurang Zaib, Rizwan Ul Haq, Ali J. Chamkha and Mohammad Mehdi Rashidi

The purpose of this paper is to present an inclusive study of the mixed convective flow involving micropolar fluid holding kerosene/water-based TiO2 nanoparticle towards a…

Abstract

Purpose

The purpose of this paper is to present an inclusive study of the mixed convective flow involving micropolar fluid holding kerosene/water-based TiO2 nanoparticle towards a vertical Riga surface with partial slip. The outcomes are confined for opposing and assisting flows.

Design/methodology/approach

Similarity equations are acquired and then worked out numerically by the Keller box technique.

Findings

Impacts of significant parameters on microrotation velocity, temperature distribution, velocity profile together with the Nusselt number and the skin friction are argued with the help of graphs. Two solutions are achieved in opposing flow, while the solution is unique in assisting flow. It is also monitored that the separation of boundary layer delays because of micropolar parameter and accelerates because of volume fraction.

Originality/value

The authors trust that all these results are new and significant for researchers.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 29 no. 5
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 3 December 2018

Aurang Zaib, Rizwan Ul Haq, A.J. Chamkha and M.M. Rashidi

The study aims to numerically examine the impact of nanoparticles on an unsteady flow of a Williamson fluid past a permeable convectively heated shrinking sheet.

Abstract

Purpose

The study aims to numerically examine the impact of nanoparticles on an unsteady flow of a Williamson fluid past a permeable convectively heated shrinking sheet.

Design/methodology/approach

In sort of the solution of the governing differential equations, suitable transformation variables are used to get the system of ODEs. The converted equations are then numerically solved via the shooting technique.

Findings

The impacts of such parameters on the velocity profile, temperature distribution and the concentration of nanoparticles are examined through graphs and tables. The results point out that multiple solutions are achieved for certain values of the suction parameter and for decelerating flow, while for accelerating flow, the solution is unique. Further, the non-Newtonian parameter reduces the fluid velocity and boosts the temperature distribution and concentration of nanoparticles in the first solution, while the reverse drift is noticed in the second solution.

Practical implications

The current results may be used in many applications such as biomedicine, industrial, electronics and solar energy.

Originality/value

The authors think that the current results are new and significant, which are used in many applications such as biomedicine, industrial, electronics and solar energy. The results have not been considered elsewhere.

Details

World Journal of Engineering, vol. 15 no. 6
Type: Research Article
ISSN: 1708-5284

Keywords

Article
Publication date: 11 January 2021

Mostafa Esmaeili, Hamed Hashemi Mehne and D.D. Ganji

This study aims to explore the idea of solving the problem of squeezing nanofluid flow between two parallel plates using a novel mathematical method.

Abstract

Purpose

This study aims to explore the idea of solving the problem of squeezing nanofluid flow between two parallel plates using a novel mathematical method.

Design/methodology/approach

The unsteady squeezing flow is a coupled fourth-order boundary value problem with flow velocity and temperature as the desired unknowns. In the first step, the conditions that guarantee the existence of a unique solution are obtained. Then following Green’s function-based approach, an iterative method for solving the problem is developed.

Findings

The accuracy of the method is examined by comparing the obtained results with existing numerical data, indicating excellent agreement between the two. In addition, the effects of nanoparticle shape and volume fraction on the flow and heat transfer characteristics are addressed. The results reveal that although the nanoparticle shape strongly affects the temperature distribution in the squeezing flow, it only has a slight impact on the velocity field. Furthermore, the highest and lowest Nusselt numbers belong to the platelets and spherical nanoparticles, respectively.

Originality/value

A semi-analytical method with computational support is developed for solving the unsteady squeezing flow problem. Moreover, the existence and uniqueness of the solution are discussed for the first time.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 31 no. 9
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 11 October 2018

Fatinnabila Kamal, Khairy Zaimi, Anuar Ishak and Ioan Pop

This paper aims to analyze the behavior of the stagnation-point flow and heat transfer over a permeable stretching/shrinking sheet in the presence of the viscous…

Abstract

Purpose

This paper aims to analyze the behavior of the stagnation-point flow and heat transfer over a permeable stretching/shrinking sheet in the presence of the viscous dissipation and heat source effects.

Design/methodology/approach

The governing partial differential equations are converted into ordinary differential equations by similarity transformations before being solved numerically using the bvp4c function built in Matlab software. Effects of suction/injection parameter and heat source parameter on the skin friction and heat transfer coefficients as well as the velocity and temperature profiles are presented in the forms of tables and graphs. A temporal stability analysis will be conducted to verify which solution is stable for the dual solutions exist for the shrinking case.

Findings

The analysis indicates that the skin friction coefficient and the local Nusselt number as well as the velocity and temperature were influenced by suction/injection parameter. In contrast, only the local Nusselt number, which represents heat transfer rate at the surface, was affected by heat source effect. Further, numerical results showed that dual solutions were found to exist for the certain range of shrinking case. Then, the stability analysis is performed, and it is confirmed that the first solution is linearly stable and has real physical implication, while the second solution is not.

Practical implications

In practice, the study of the steady two-dimensional stagnation-point flow and heat transfer past a permeable stretching/shrinking sheet in the presence of heat source effect is very crucial and useful. The problems involving fluid flow over stretching or shrinking surfaces can be found in many industrial manufacturing processes such as hot rolling, paper production and spinning of fibers. Owing to the numerous applications, the study of stretching/shrinking sheet was subsequently extended by many authors to explore various aspects of skin friction coefficient and heat transfer in a fluid. Besides that, the study of suction/injection on the boundary layer flow also has important applications in the field of aerodynamics and space science.

Originality/value

Although many studies on viscous fluid has been investigated, there is still limited discoveries found on the heat source and suction/injection effects. Indeed, this paper managed to obtain the second (dual) solutions and stability analysis is performed. The authors believe that all the results are original and have not been published elsewhere.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 28 no. 11
Type: Research Article
ISSN: 0961-5539

Keywords

Open Access
Article
Publication date: 14 November 2018

Sidra Shahzadi, Rizwan Khan, Maryam Toor and Ayaz ul Haq

The accounting system plays an important role in the company’s organizational structure. The purpose of this paper is to demonstrate that the integration of management…

25553

Abstract

Purpose

The accounting system plays an important role in the company’s organizational structure. The purpose of this paper is to demonstrate that the integration of management accounting practices is subject to coordination between external and internal factors and accounting management practices.

Design/methodology/approach

Therefore, the authors move to the contingency model to determine the most significant external “unexpected factors” that explain the introduction of management practices for the management of the various stages of development. The exploratory study examines a sample of Pakistani companies from various sectors.

Findings

This study reveals that the main factors of uncertainty that affect the organizational structure, environmental uncertainty, advanced production technology, just-in-time method strategy, integrated management of quality and structure findings reveal that MAP affected all process and changes all system in simple to complex system in Pakistani’s industries.

Practical implications

This study is to acquisition the impact of external factors on management accounting practices, to find the impact of internal factors on management accounting practices, to establish the management accounting practices undertaken by the companies in Pakistan.

Originality/value

The study contributes to the literature by enhancing our understanding for the impact of external and internal factors on management accounting practices in Pakistan.

Details

Asian Journal of Accounting Research, vol. 3 no. 2
Type: Research Article
ISSN: 2443-4175

Keywords

Article
Publication date: 2 September 2019

Dirk De Clercq, Inam Ul Haq and Muhammad Umer Azeem

With a basis in the conservation of resources theory, the purpose of this paper is to investigate the relationship between employees’ experience of time-related work…

2016

Abstract

Purpose

With a basis in the conservation of resources theory, the purpose of this paper is to investigate the relationship between employees’ experience of time-related work stress and their engagement in counterproductive work behavior (CWB), as well as the invigorating roles that different deviant personality traits might play in this process.

Design/methodology/approach

Two-wave survey data with a time lag of three weeks were collected from 127 employees in Pakistani organizations.

Findings

Employees’ sense that they have insufficient time to do their job tasks spurs their CWB, and this effect is particularly strong if they have strong Machiavellian, narcissistic or psychopathic tendencies.

Originality/value

This study adds to extant research by identifying employees’ time-related work stress as an understudied driver of their CWB and the three personality traits that constitute the dark triad as triggers of the translation of time-related work stress into CWB.

Details

Personnel Review, vol. 48 no. 7
Type: Research Article
ISSN: 0048-3486

Keywords

Article
Publication date: 22 July 2019

Muhammad Waqas

This paper aims to address stagnation point flow of cross nanofluid in frames of hydromagnetics. Flow analysis subjected to expanding-contracting cylinder is studied.

Abstract

Purpose

This paper aims to address stagnation point flow of cross nanofluid in frames of hydromagnetics. Flow analysis subjected to expanding-contracting cylinder is studied.

Design/methodology/approach

Nonlinear problems are computed by using bvp4c procedure.

Findings

Radius of curvature and temperature-dependent heat sink-source significantly affects heat-mass transport mechanisms for cylindrical surface.

Originality/value

No such analysis has yet been reported.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 30 no. 4
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 17 May 2022

M. Ikram Ul Haq, Abdul Khaliq Alvi, Muhammad Akram Somroo, Nadeem Akhtar and Ashfaque Ahmed

Current research addresses the issue of brand loyalty while identifying its potential predictors. The research also examines the direct impact of brand credibility on…

Abstract

Purpose

Current research addresses the issue of brand loyalty while identifying its potential predictors. The research also examines the direct impact of brand credibility on brand loyalty and attitude toward brand and the direct impact of attitude toward brand and on brand loyalty respectively. Moreover, this research examines the mediating effect of attitude toward brand for the relationship of brand credibility and brand loyalty.

Design/methodology/approach

This is a cross-sectional research. Data is collected with the help of structured questionnaire. Simple random sampling technique is used for gathering the data from 220 Samsung users from Lahore, Pakistan.

Findings

Results indicate that brand credibility has a positive influence on attitude toward brand and brand loyalty respectively. Attitude toward brand partially intervenes the relation of brand credibility and brand loyalty.

Research limitations/implications

There are some limitations of the current research. It includes only the customers of Samsung mobile. Data is collected from the customers of Lahore, Pakistan, only. This research can also be conducted among the customers of OPPO, Vivo and Apple and compare the results of current research with the results of OPPO, Vivo and Apple, which will provide the useful insights. This kind of research will also be conducted among the customers of other kinds of products like FMCGs, luxury items and even on the organizations of industrial products for generalizability. In future, customers of other cities of Pakistan like Karachi, Multan and Faisalabad may also be included for generalization.

Practical implications

This research provides a practical framework for the marketing department of Samsung mobiles and explains how brand credibility shape the brand loyalty through the path of attitude toward Samsung mobiles. So, Samsung mobiles can maintain current policies regarding brand credibility and attitude toward brand for attaining the better level of brand loyalty. Longitudinal research studies on these variables will also be helpful for the marketing department of Samsung for checking the level of propose relationships periodically and comparing it with previous results which will provide the true picture about propose relationships. If the value of propose relationships increases or remains at same level, then Samsung can maintain the current policies about these variables and if the value of these variables decreases, the Samsung will improve the current policies about these variables.

Originality/value

This research contributed in theory of reasoned action by proposing the brand credibility, attitude toward brand and brand loyalty in single model. Before this, these relations were explained separately. This research adds to the body of literature by checking the mediating effect of attitude toward brand for the relationship of brand credibility and brand loyalty.

Details

Journal of Economic and Administrative Sciences, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1026-4116

Keywords

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