Search results

1 – 10 of 245
Article
Publication date: 30 November 2021

Syeda Wajiha Kazmi and Waqar Ahmed

The purpose of this paper is to evaluate and understand the factors that contribute to the enhancement in the process of supply chain activities, specifically among manufacturing…

Abstract

Purpose

The purpose of this paper is to evaluate and understand the factors that contribute to the enhancement in the process of supply chain activities, specifically among manufacturing industries.

Design/methodology/approach

This paper follows the quantitative approach by disseminating a structured questionnaire to supply chain practitioners working in manufacturing industries. A sample of 109 responses is gathered from senior employees involved in sales and operations planning. Exploratory and confirmatory factor analyses are performed to evaluate the reliability and validity of the model. Lastly, SmartPLS is used to test the hypotheses proposed in the study.

Findings

The findings revealed that demand sensing and managing practices positively impact supply chain performance by creating dynamic distribution capabilities. It is observed that distribution capabilities integrate both efficient and effective handling of resources. However, demand management practice has insignificant relationship with supply chain performance.

Research limitations/implications

The authors suggest that supply chain management must expand in firms, and importance must be given as supply chain performance can provide competitive advantage in order to sustain in today's competitive market.

Practical implications

The findings can help decision-makers working in the planning process by identifying the right tools to sense the market and react accordingly.

Originality/value

This paper is an initial effort to understand the dynamic distribution capabilities by establishing the link with the studied variables, especially in the manufacturing industries in Pakistan.

Details

Benchmarking: An International Journal, vol. 29 no. 9
Type: Research Article
ISSN: 1463-5771

Keywords

Article
Publication date: 2 October 2017

Syed Tauseef Mohyud-Din, Muhammad Usman, Kamran Afaq, Muhammad Hamid and Wei Wang

The purpose of this study is to analyze the effects of carbon nanotubes (CNTs) in the Marangoni convection boundary layer viscous fluid flow. The analysis and formulation for both…

Abstract

Purpose

The purpose of this study is to analyze the effects of carbon nanotubes (CNTs) in the Marangoni convection boundary layer viscous fluid flow. The analysis and formulation for both types of CNTs, namely, single-walled (SWCNTs) and multi-walled (MWCNTs), are described. The influence of thermal radiation effect assumed in the form of energy expression.

Design/methodology/approach

Appropriate transformations reduced the partial differential systems to a set of nonlinear ordinary differential equations (ODEs). The obtained nonlinear ODE set is solved via the least squares method. A detailed comparison between outcomes obtained by the least squares method, RK-4 and already published work is available.

Findings

Nusselt number was analyzed and found to be more effective for nanoparticle volume fraction and larger radiation parameters. Additionally, the error and convergence analysis for the least squares method was presented to show the efficiency of the said algorithm.

Originality/value

The results reveal that velocity is a decreasing function of suction for both CNTs. While enhancing the nanoparticle volume fraction, an increase for both thermal boundary layer thickness and temperature was attained. The radiation parameter has an increasing function as temperature. Velocity behavior is the same for nanoparticle volume fraction and suction. It was observed that velocity is less in SWCNTs as compared to MWCNTs.

Details

Engineering Computations, vol. 34 no. 7
Type: Research Article
ISSN: 0264-4401

Keywords

Article
Publication date: 8 July 2019

Davood Toghraie and Ehsan Shirani

The purpose of this paper is to investigate the mixed convection of a two-phase water–aluminum oxide nanofluid in a cavity under a uniform magnetic field.

Abstract

Purpose

The purpose of this paper is to investigate the mixed convection of a two-phase water–aluminum oxide nanofluid in a cavity under a uniform magnetic field.

Design/methodology/approach

The upper wall of the cavity is cold and the lower wall is warm. The effects of different values of Richardson number, Hartmann number, cavitation length and solid nanoparticles concentration on the flow and temperature field and heat transfer rate were evaluated. In this paper, the heat flux was assumed to be constant of 10 (W/m2) and the Reynolds number was assumed to be constant of 300 and the Hartmann number and the volume fraction of solid nanoparticles varied from 0 to 60 and 0 to 0.06, respectively. The Richardson number was considered to be 0.1, 1 and 5. Aspect ratios were 1, 1.5 and 2.

Findings

Comparison of the results of this paper with the results of the numerical and experimental studies of other researchers showed a good correlation. The results were presented in the form of velocity and temperature profiles, stream and isotherm lines and Nusselt numbers. The results showed that by increasing the Hartmann number, the heat transfer rate decreases. An increase from 0 to 20 in Hartmann number results in a 20 per cent decrease in Nusselt numbers, and by increasing the Hartmann number from 20 to 40, a 16 per cent decrease is observed in Nusselt number. Accordingly, it is inferred that by increasing the Hartmann number, the reduction in the Nusselt number is decreased. As the Richardson number increased, the heat transfer rate and, consequently, the Nusselt number increased. Therefore, an increase in the Richardson number results in an increase of the Nusselt number, that is, an increase in Richardson number from 0.1 to 1 and from 1 to 5 results in 37 and 47 per cent increase in Nusselt number, respectively.

Originality/value

Even though there have been numerous investigations conducted on convection in cavities under various configurations and boundary conditions, relatively few studies are conducted for the case of nanofluid mixed convection in square lid-driven cavity under the effect of magnetic field using two-phase model.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 30 no. 5
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 10 August 2020

Akinbowale T. Akinshilo, Gbeminiyi M. Sobamowo, Osamudiamen Olaye and Adeleke O. Illegbusi

In this paper, hybrid multienzyme biosensor system, which detects analyte through molecular conversion into signal response, is analyzed and presented. The biokinetic effects of…

Abstract

Purpose

In this paper, hybrid multienzyme biosensor system, which detects analyte through molecular conversion into signal response, is analyzed and presented. The biokinetic effects of pertinent parameters such as Michaelis–Menten constant, inhibitor inhibition and substrate inhibition modulus on biochemical reactions are investigated.

Design/methodology/approach

Biochemical reaction models are described by five nonlinear equations for bisubstrate amperometric system analyzed adopting the regular perturbation method.

Findings

Results obtained reveal that increasing Michaelis–Menten constant of oxygen causes a significant decrease in hydrogen peroxide concentration while increasing Michaelis–Menten constant of glucose shows increasing effect on oxygen concentration. Hence, results obtained from this work serve as reference for further analysis of concentration models and offer useful insight to relevant applications such as food safety, environmental and biomedical applications.

Practical implications

This work serves as reference for further analysis of concentration models and offers useful insight to relevant applications such as food safety, environmental and biomedical applications.

Originality/value

This paper examines the effect of biokinetic parameters on the concentration of the hybrid multienzyme biosensor. Here the effects of parameters such as inhibitor inhibition, substrate inhibition and Michealis–Menten were investigated on substrate, inhibition and product concentrations. It is illustrated from result that inhibitor parameter slows enzymatic catalytic reaction while substrate enhances reaction. This study applied approximate analytical scheme to investigate the biokinetic effects, adopting the regular perturbation scheme.

Details

Multidiscipline Modeling in Materials and Structures, vol. 17 no. 2
Type: Research Article
ISSN: 1573-6105

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: 3 April 2018

Najib Hdhiri and Brahim Ben Beya

The purpose of this study is to investigate the effects of heat generation or absorption on heat transfer and fluid flow within two- and three-dimensional enclosure for…

78

Abstract

Purpose

The purpose of this study is to investigate the effects of heat generation or absorption on heat transfer and fluid flow within two- and three-dimensional enclosure for homogeneous medium filled with different metal liquid. Numerical results are presented and analyzed in terms of fluid flow, thermal field structures, as well as average Nusselt number profiles over a wide range of dimensionless quantities, Grashof number (Gr) (104 and 105), SQ (varied between −500 to 500) and Prandtl number (Pr = 0.015, 0.024 and 0.0321). The results indicate that when the conductive regime is established for a Grashof number Gr = 104, the 2D model is valid and predicts all three-dimensional results with negligible difference. This was not the case in the convective regime (Gr = 105) where the effect of the third direction becomes important, where a 2D-3D difference was seen with about 37 per cent. Also, in most cases, the authors find that the heat absorption phenomena have the opposite effect with respect to the heat generation.

Design/methodology/approach

Numerical results are presented and analyzed in terms of fluid flow, thermal field structures, as well as average Nusselt number profiles over a wide range of dimensionless quantities.

Findings

Grashof number (Gr) (104 and 105), SQ (varied between −500 to 500) and Prandtl number (Pr = 0.015, 0.024 and 0.0321).

Originality/value

The results indicate that when the conductive regime is established for a Grashof number Gr = 104, the 2D model is valid and predicts all three-dimensional results with negligible difference.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 28 no. 4
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 25 November 2013

Alireza Fathi and Ahmad Mozaffari

The purpose of the current investigation is to design a robust and reliable computational framework to effectively identify the nonlinear behavior of shape memory alloy (SMA…

Abstract

Purpose

The purpose of the current investigation is to design a robust and reliable computational framework to effectively identify the nonlinear behavior of shape memory alloy (SMA) actuators, as one of the most applicable types of actuators in engineering and industry. The motivation of proposing such an intelligent paradigm emanates in the pursuit of fulfilling the necessity of devising a simple yet effective identification system capable of modeling the hysteric dynamical respond of SMA actuators.

Design/methodology/approach

To address the requirements of designing a pragmatic identification system, the authors integrate a set of fast yet reliable intelligent methodologies and provide a predictive tool capable of realizing the nonlinear hysteric behavior of SMA actuators in a computationally efficient fashion. First, the authors utilize the governing equations to design a gray box Hammerstein-Wiener identifier model. At the next step, they adopt a computationally efficient metaheuristic algorithm to elicit the optimum operating parameters of the gray box identifier.

Findings

Applying the proposed hybrid identifier framework allows the authors to find out its advantages in modeling the behavior of SMA actuator. Through different experiments, the authors conclude that the proposed identifier can be used for identification of highly nonlinear dynamic behavior of SMA actuators. Furthermore, by extending the conclusions and expounding the obtained results, one can easily infer that such a hybrid method may be conveniently applied to model other engineering phenomena that possess dynamic nonlinear reactions. Based on the exerted experiments and implementing the method, the authors come to the conclusion that integrating the power of metaheuristic exploration/exploitation with gray box identifier results a predictive paradigm that much more computationally efficient as compared with black box identifiers such as neural networks. Additionally, the derived gray box method has a higher degree of preference over the black box identifiers, as it allows a manipulated expert to extract the knowledge of the system at hand.

Originality/value

The originality of the research paper is twofold. From the practical (engineering) point of view, the authors built a prototype biased-spring SMA actuator and carried out several experiments to ascertain and validate the parameters of the model. From the computational point of view, the authors seek for designing a novel identifier that overcomes the main flaws associated with the performance of black-box identifiers that are the lack of a mean for extracting the governing knowledge of the system at hand, and high computational expense pertinent to the structure of black-box identifiers.

Details

International Journal of Intelligent Computing and Cybernetics, vol. 6 no. 4
Type: Research Article
ISSN: 1756-378X

Keywords

Article
Publication date: 5 September 2016

R. Ellahi, A. Zeeshan and Mohsan Hassan

The purpose of this paper is to study the particle shape effects on Marangoni convection boundary layer flow of a nanofluid. The paper aims to discuss diverse issues befell for…

Abstract

Purpose

The purpose of this paper is to study the particle shape effects on Marangoni convection boundary layer flow of a nanofluid. The paper aims to discuss diverse issues befell for the said model.

Design/methodology/approach

The work undertaken is a blend of numerical and analytical studies. Analytical and numerical solutions of nonlinear coupled equations are developed by means of Mathematica package BVPh 2.0 based on the homotopy analysis method.

Findings

The velocity of nanofluid decreases by increasing particle volume friction and similarity parameters. With the increase in particle volume friction and similarity parameter, temperature profile is correspondingly enhanced and decline. The lowest velocity and highest temperature of nanofluid is cause by needle- and disc-shaped particle. Consequence for interface velocity and the surface temperature gradient are perceived by numeric set of results. It is found that the interface velocity is declined by increasing particle volume friction and volume concentration of ethylene glycol in the water. The minimum interface velocity is seen by needle-shaped particle and 30 percent concentrations of ethylene glycol. With increase in volume friction and size of particle, the behaviors of surface temperature gradient are found decreasing and increasing function, respectively. The maximum heat transfer rate at the surface is achieved when we chose sphere nanoparticles and 90 percent concentrations of ethylene glycol as compared to other shapes and concentrations.

Originality/value

This model is investigated for the first time, as the authors know.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 26 no. 7
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 28 October 2014

M. Sheikholeslami, R. Ellahi, Mohsan Hassan and Soheil Soleimani

The purpose of this paper is to study the effects of natural convection heat transfer in a cold outer circular enclosure containing a hot inner elliptic circular cylinder. The…

1068

Abstract

Purpose

The purpose of this paper is to study the effects of natural convection heat transfer in a cold outer circular enclosure containing a hot inner elliptic circular cylinder. The fluid in the enclosure is Cu-water nanofluid. The main emphasis is to find the numerical treatment for the said mathematical model. The effects of Rayleigh number, inclined angle of elliptic inner cylinder, effective of thermal conductivity and viscosity of nanofluid, volume fraction of nanoparticles on the flow and heat transfer characteristics have been examined.

Design/methodology/approach

A very effective and higher order numerical scheme Control Volume-based Finite Element Method (CVFEM) is used to solve the resulting coupled equations. The numerical investigation is carried out for different governing parameters namely; the Rayleigh number, nanoparticle volume fraction and inclined angle of elliptic inner cylinder. The effective thermal conductivity and viscosity of nanofluid are calculated using the Maxwell-Garnetts (MG) and Brinkman models, respectively.

Findings

The results reveal that Nusselt number increases with an increase of nanoparticle volume fraction, Rayleigh numbers and inclination angle. Also it can be found that increasing Rayleigh number leads to a decrease in heat transfer enhancement. For high Rayleigh number the minimum heat transfer enhancement ratio occurs at.

Originality/value

To the best of the authors’ knowledge, no such analysis is available in the literature which can describe the natural convection heat transfer in a nanofluid filled enclosure with elliptic inner cylinder by means of CVFEM.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 24 no. 8
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 9 November 2018

Yuan Ma, Rasul Mohebbi, Mohammad Mehdi Rashidi and Zhigang Yang

This paper aims to numerically investigate the natural convection heat transfer of multi-wall carbon nanotubes (MWCNTs)-water nanofluid in U-shaped enclosure equipped with a hot…

269

Abstract

Purpose

This paper aims to numerically investigate the natural convection heat transfer of multi-wall carbon nanotubes (MWCNTs)-water nanofluid in U-shaped enclosure equipped with a hot obstacle by using the lattice Boltzmann method.

Design/methodology/approach

The combination of the three topics (U-shaped enclosure, different positions of the hot obstacle and MWCNTs-water nanofluid) is innovative in the present study. In total, 15 different positions of the hot obstacle have been arranged, and the effects of pertinent parameters such as Rayleigh numbers, the solid volume fraction of the MWCNTs nanoparticles on the flow field, temperature distribution and the rate of heat transfer inside the enclosure are also investigated.

Findings

It is found that the average Nusselt number increased by raising the Rayleigh number, and so did the nanoparticle solid volume fraction regardless the position of the hot obstacle. Moreover, enclosures where the hot obstacle is located at the bottom region proved to provide a better rate of heat transfer at high Rayleigh number (106). It is concluded that at a low Ra number (103-105), the higher heat transfer rate and Nu number will be obtained when the hot obstacle is located in the left or right channel.

Originality/value

In the literature, no trace of studying the natural convection of nanofluids in U-shaped enclosures with heating obstacles was found. Also, MWCNTs were less used as nanoparticles. As the natural convection of nanofluids in thermal engineering applications would expand the existing knowledge, the current researchers conducted a numerical study of the natural convection of Maxwell nanofluid with MWCNTs in U-shaped enclosure equipped with a hot obstacle by using lattice Boltzmann method.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 29 no. 1
Type: Research Article
ISSN: 0961-5539

Keywords

1 – 10 of 245