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Article
Publication date: 1 July 2020

Zhang Jun, Muhammad Ayaz Akbar, Wang Xin lei and Danaish

The purpose of this study is to present the optimization of the design and measurement principle of a six-component force/thrust measurement stand. This study highlights some key…

Abstract

Purpose

The purpose of this study is to present the optimization of the design and measurement principle of a six-component force/thrust measurement stand. This study highlights some key problems found in previous studies and proposes improvements in design and measurement principles.

Design/methodology/approach

The numerical simulation approach is used to verify the proposed improvements. An improved design and measurement principle are proposed and to verify the proposed improvements, simulation experiments are conducted. The data obtained from simulations are analyzed through the proposed improved measurement principle. The proposed stand is capable of measuring the main thrust and other components as pitch, yaw and roll. The stand is capable of measuring the main thrust more than 50,000 N and orthogonal thrust components more than 1,000 N. Improved design of measurement stand is also capable of measuring moments in three-axis more than 150 Nm. Thrust stand consists of two main sections: front and rare. Stand consists of seven piezoelectric force sensors to measure all components of force.

Findings

The simulations experiments and basic theoretical laws of kinematics prove that the proposed design indeed improves the precision of measurement and also enhance the efficiency of design. Evaluation results show that the measurement stand designed is highly functional. Non-linearity, coupling and repeatability errors are found to be within acceptable range during numerical simulations.

Originality/value

This study is unique in this kind. This study identifies the key problems found in previous studies and proposes an improved design and measurement principle. This study provides evidence for the improvements to be really functional and necessary.

Details

Journal of Engineering, Design and Technology , vol. 18 no. 5
Type: Research Article
ISSN: 1726-0531

Keywords

Open Access
Article
Publication date: 8 February 2018

Ismail Ismail, Muhammad Sohail, Hammad Gilani, Anwar Ali, Kiramat Hussain, Kamran Hussain, Bhaskar Singh Karky, Faisal Mueen Qamer, Waqas Qazi, Wu Ning and Rajan Kotru

The purpose of the study is to analyse the occurrence and distribution of different tree species in Gilgit-Baltistan, Pakistan, as a baseline for further inventories, and estimate…

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Abstract

Purpose

The purpose of the study is to analyse the occurrence and distribution of different tree species in Gilgit-Baltistan, Pakistan, as a baseline for further inventories, and estimate the biomass per species and plot. Furthermore, it aims to measure forest biodiversity using established formulae for tree species diversity index, richness, evenness and accumulative curve.

Design/methodology/approach

Field data were collected, including stratification of forest sample plots. Statistical analysis of the data was carried out, and locally appropriate allometric equations were applied for biomass estimation.

Findings

Representative circular 556 forest sample plots of 1,000 m2 contained 13,135 trees belonging to nine tree species with a total aboveground biomass of 12,887 tonnes. Sixty-eight per cent of the trees were found between 2,600 and 3,400 masl; approximately 63 per cent had a diameter at breast height equal to 30 cm, and 45 per cent were less than 12 m in height. The Shannon diversity index was 1.82, and Simpson’s index of diversity was 0.813.

Research limitations/implications

Rough terrain, long distances, harsh weather conditions and location of forest in steep narrow valleys presented challenges for the field crews, and meant that fieldwork took longer than planned.

Practical implications

Estimating biomass in Gilgit-Baltistan’s forests using locally developed allometric equations will provide transparency in estimates of forest reference levels, National Forest Monitoring System in Pakistan and devising Reducing Emissions from Deforestation and Forest Degradation national strategies and for effective implementation.

Originality/value

This paper presents the first detailed forest inventory carried out for the dry temperate and semi-arid cold region of Gilgit-Baltistan, Pakistan.

Details

International Journal of Climate Change Strategies and Management, vol. 10 no. 4
Type: Research Article
ISSN: 1756-8692

Keywords

Article
Publication date: 16 August 2019

S. Bilal, Muhammad Sohail and Rahila Naz

The purpose of this paper is to highlight the studies of momentum and transmission of heat on mixed convection boundary layer Darcy‒Forchheimer flow of Casson liquid over a linear…

Abstract

Purpose

The purpose of this paper is to highlight the studies of momentum and transmission of heat on mixed convection boundary layer Darcy‒Forchheimer flow of Casson liquid over a linear extending surface in a porous medium. The belongings of homogeneous‒heterogeneous retorts are also affianced. The mechanism of heat transmission is braced out in the form of Cattaneo‒Christov heat flux. Appropriate restorations are smeared to revolutionize coupled nonlinear partial differential equations conforming to momentum, energy and concentration of homogeneous‒heterogeneous reaction equations into coupled nonlinear ordinary differential equations (ODEs).

Design/methodology/approach

Numerical elucidations of the transmogrified ODEs are accomplished via a dexterous and trustworthy scheme, namely optimal homotopy analysis method. The convergence of planned scheme is exposed with the support of error table.

Findings

The exploration of mixed convection Darcy‒Forchheimer MHD boundary layer flow of incompressible Casson fluid by the linear stretched surface with Cattaneo‒Christov heat flux model and homogeneous‒heterogeneous reactions is checked in this research. Imitations of the core subsidized flow parameters on velocity, temperature and concentration of homogeneous‒heterogeneous reactions solutions are conscripted. From the recent deliberation, remarkable annotations are as follows: non-dimensional velocities in xa− and xb− directions shrink, whereas the non-dimensional temperature upsurges when the Casson fluid parameter ameliorates. Similar impact of Casson fluid parameter, magnetic parameter, mixed convection parameter, inertia parameter, and porosity parameter is observed for both the components of velocity field. An escalation in magnetic parameter shows the opposite attitude of temperature field as compared with velocity profile. Similar bearing of Casson fluid parameter is observed for both temperature and velocity fields. Enhancement in concentration rate is observed for growing values of (Ns) and (Sc), and it reduces for (k1). Both temperature and concentration of homogeneous‒heterogeneous upturn by mounting the magnetic parameter. Demeanor of magnetic parameter, Casson fluid parameter, heat generation parameter is opposite to that of Prandtl number and thermal relaxation parameter on temperature profile.

Practical implications

In many industrial and engineering applications, the current exploration is utilized for the transport of heat and mass in any system.

Originality/value

As far as novelty of this work is concerned this is an innovative study and such analysis has not been considered so far.

Details

Multidiscipline Modeling in Materials and Structures, vol. 15 no. 6
Type: Research Article
ISSN: 1573-6105

Keywords

Article
Publication date: 28 August 2019

R. Ellahi, Sadiq M. Sait, N. Shehzad and Z. Ayaz

The purpose of this paper is to present the investigation of the pressure-driven flow of aluminum oxide-water based nanofluid with the combined effect of entropy generation and…

295

Abstract

Purpose

The purpose of this paper is to present the investigation of the pressure-driven flow of aluminum oxide-water based nanofluid with the combined effect of entropy generation and radiative electro-magnetohydrodynamics filled with porous media inside a symmetric wavy channel.

Design/methodology/approach

The non-linear coupled differential equations are first converted into a number of ordinary differential equations with appropriate transformations and then analytical solutions are obtained by homotopic approach. Numerical simulation has been designed by the most efficient approach known homotopic-based Mathematica package BVPh 2.0 technique. The long wavelength approximation over the channel walls is taken into account. The obtained analytical results have been validated through graphs to infer the role of most involved pertinent parameters, whereas the characteristics of heat transfer and shear stress phenomena are presented and examined numerically.

Findings

It is found that the velocity profile decreases near to the channel. This is in accordance with the physical expectation because resistive force acts opposite the direction of fluid motion, which causes a decrease in velocity. It is seen that when the electromagnetic parameter increases then the velocity close to the central walls decreases whereas quite an opposite behavior is noted near to the walls. This happens because of the combined influence of electro-magnetohydrodynamics. It is perceived that by increasing the magnetic field parameter, Darcy number, radiation parameter, electromagnetic parameter and the temperature profile increases, and this is because of thermal buoyancy effect. For radiation and electromagnetic parameters, energy loss at the lower wall has substantial impact compared to the upper wall. Residual error minimizes at 20th order iterations.

Originality/value

The proposed prospective model is designed to explore the simultaneous effects of aluminum oxide-water base nanofluid, electro-magnetohydrodynamics and entropy generation through porous media. To the best of author’s knowledge, this model is reported for the first time.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 30 no. 2
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 23 June 2020

S. Sarkar, R.N. Jana and S. Das

The purpose of this article is to analyze the heat and mass transfer with entropy generation during magnetohydrodynamics (MHD) flow of non-Newtonian Sisko nanofluid over a…

Abstract

Purpose

The purpose of this article is to analyze the heat and mass transfer with entropy generation during magnetohydrodynamics (MHD) flow of non-Newtonian Sisko nanofluid over a linearly stretching cylinder under the influence of velocity slip, chemical reaction and thermal radiation. The Brownian motion, thermophoresis and activation energy are assimilated in this nanofluid model. Convective boundary conditions on heat and mass transfer are considered. The physical model may have diverse applications in several areas of technology underlying thermohydrodynamics including supercritical fluid extraction, refrigeration, ink-jet printing and so on.

Design/methodology/approach

The dimensional governing equations are nondimensionalized by using appropriate similarity variables. The resulting boundary value problem is converted into initial value problem using the method of superposition and numerically computed by employing well-known fourth-order Runge–Kutta–Fehlberg approach along with shooting technique (RKF4SM). The quantitative impacts of emerging physical parameters on the velocity, temperature, concentration, skin friction coefficient, Nusselt number, Sherwood number, entropy generation rate and Bejan number are presented graphically and in tabular form, and the salient features are comprehensively discussed.

Findings

From graphical outcomes, it is concluded that the slip parameters greatly influence the flow characteristics. Fluid temperature is elevated with rising radiation parameter and thermal Biot number. Nanoparticle concentration is reported in decreasing form with activation energy parameter. Entropy is found to be an increasing function of magnetic field, Brownian motion and material parameters. The entropy is less generated for shear-thinning fluid compared to shear-thickening as well as Newtonian fluids in the system.

Originality/value

Till now no study has been documented to explore the impact of binary chemical reaction with Arrhenius activation energy on entropy generation in an MHD boundary layer flow of non-Newtonian Sisko nanofluid over a linear stretching cylinder with velocity slip and convective boundary conditions.

Details

Multidiscipline Modeling in Materials and Structures, vol. 16 no. 5
Type: Research Article
ISSN: 1573-6105

Keywords

Article
Publication date: 22 July 2020

K. Vafai, Ambreen A. Khan, G. Fatima, Sadiq M. Sait and R. Ellahi

This paper aims to investigate the effect of Powell–Eyring fluid induced by a stretched sheet. Heat and mass transfer under the influence of magnetic dipole over a stretching…

Abstract

Purpose

This paper aims to investigate the effect of Powell–Eyring fluid induced by a stretched sheet. Heat and mass transfer under the influence of magnetic dipole over a stretching sheet are taken into account.

Design/methodology/approach

Nonlinear coupled governing equations are solved using the optimal homotopy asymptotic technique, and a computer software package BVPh 2.0 is used for numerical computations.

Findings

Impact of significant quantities is graphically examined. It is seen that the heat transfer deceases for higher values of viscous dissipation parameter, radiation parameter, Dufour number, whereas it increases for bigger values of Prandtl number. The numerical results have been validated through comparison with existing literature as a special case of proposed model and perceived that the Soret number has reining role to increase the rate of heat transfer.

Originality/value

To the best of the authors’ knowledge, this study is reported for the first time.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 31 no. 4
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 6 November 2017

Sumit Gupta and Kalpna Sharma

The purpose of this study is to analyze magnetohydrodynamic three-dimensional flow of Casson nanofluid over a stretching sheet in presence of thermophoresis and Brownian motion…

Abstract

Purpose

The purpose of this study is to analyze magnetohydrodynamic three-dimensional flow of Casson nanofluid over a stretching sheet in presence of thermophoresis and Brownian motion effects. In contrast, the convective surface boundary conditions with the effects of radiation are applied.

Design/methodology/approach

The governing partial differential equations are transformed into highly nonlinear coupled ordinary differential equations consisting of the momentum, energy and nanoparticle concentration via suitable similarity transformations, which are then solved the using optimal homotopy analysis method (OHAM) a Mathematica Package BVPh2.0.

Findings

The influence of emerging physical flow parameters on fluid velocity component, temperature distribution and nanoparticle concentration are discussed in detail. Also, an OHAM solution demonstrates very good correlation with those obtained in the previously published results. It is noticed that OHAM can overcome the earlier restriction, assumptions and limitation of traditional perturbation method. The main advantage of this method is that OHAM can be applied directly to nonlinear differential equations without using linearization and round-off errors, and therefore, it cannot be affected by error associated to discretization.

Originality/value

Here the approximate solutions are compared with the numerical results published in earlier work.

Details

Engineering Computations, vol. 34 no. 8
Type: Research Article
ISSN: 0264-4401

Keywords

Article
Publication date: 18 March 2020

Muhammad Sohail and Rabeeah Raza

The current determination is committed to characterize the boundary layer flow of Williamson nanofluid prompted by nonlinear strained superficial under heat and mass transport…

Abstract

Purpose

The current determination is committed to characterize the boundary layer flow of Williamson nanofluid prompted by nonlinear strained superficial under heat and mass transport mechanisms. Buongiorno model is presented to view the influence of nanoparticles in fluid flow. Scrutiny has been conceded under the action of the transversely smeared magnetic field. Heat and mass relocation exploration are conducted in the companionship of radiation effects and actinic compensation.

Design/methodology/approach

Similarity variable is designated to transmute nonlinear partial differential equations of conservation laws of mass, momentum, energy and species into ordinary dimensional expressions. These constitutive and complicated ordinary differential expressions assessing the flow situation are handled efficaciously by manipulating Runge–Kutta–Fehlberg procedure (RK-5) with shooting routine.

Findings

The graphical demonstration is deliberated to scrutinize the variation in velocity, temperature and concentration profiles with respect to flow regulating parameters. Numerical data are displayed through tables in order to surmise variation in skin friction coefficient and Nusselt number. The augmenting values of fluid parameter and magnetic parameter reduces the horizontal fluid velocity, whereas normal velocity upsurges for mounting values of stretching ratio parameter. Moreover, mounting values of radiation parameter and thermophoresis parameter upsurges the temperature profile, whereas, growing values of Prandtl number lessen the temperature field.

Practical implications

The current exploration is used in many industrial and engineering applications in order to discuss the transport phenomenon.

Originality/value

Flow over a nonlinear stretched surface has numerous applications in the industry. The present attempt examines the combined influence of various physical characteristics for the flow of Williamson fluid and no such attempt exist in the available literature.

Details

Multidiscipline Modeling in Materials and Structures, vol. 16 no. 5
Type: Research Article
ISSN: 1573-6105

Keywords

Article
Publication date: 1 December 2022

Nida Gull, Muhammad Asghar, Mohsin Bashir, Xiliang Liu and Zhengde Xiong

This study aims to answer how family-supportive supervisor behavior (FSSB) reduces work–family conflict (WFC), family–work conflict (FWC) and employee turnover intention. Based on…

Abstract

Purpose

This study aims to answer how family-supportive supervisor behavior (FSSB) reduces work–family conflict (WFC), family–work conflict (FWC) and employee turnover intention. Based on the conservation of resources theory, this study examines the direct and indirect effects of emotional exhaustion between WFC/FWC and turnover intention. Moreover, this study explores FSSB moderated the role relationship between WFC/FWC and emotional exhaustion.

Design/methodology/approach

This study draws time-lagged data from two phases of a survey of health-care workers working in Chinese hospitals. In the first phase, data on WFC/FWC and turnover were collected from 407 workers. In second round, 387 employees express their feeling about emotional exhaustion and supportive supervisor behavior toward support family members. The data was collected from health-care workers, and a moderated mediation technique was tested using structural equation model-AMOS.

Findings

The findings of this study show that the positive relation between WFC/FWC and emotional exhaustion is high for employees with lower family-supportive supervisors than those with higher family-supportive supervisors. This finding provides further insight into the mechanism of how family and work conflicts impact turnover intention.

Originality/value

To the best of the authors’ knowledge, this is the first empirical study based on the conservation of resources theory, the relationship between WFC/FWC and turnover intention, considering the mediating role of emotional exhaustion and the moderating effects of FSSB. This paper proposes that FSSB can reduce WFCs, addressing a significant research gap in the literature.

Details

International Journal of Conflict Management, vol. 34 no. 2
Type: Research Article
ISSN: 1044-4068

Keywords

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