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Article
Publication date: 1 October 1998

Peter J. Murk and Jeffrey L. Walls

Most current planning models are linear in design and concept. However, in practice contextual demands are not always linear. The planning wheel is a promising, new planning…

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Abstract

Most current planning models are linear in design and concept. However, in practice contextual demands are not always linear. The planning wheel is a promising, new planning model. The planning wheel bridges the gap between linear and nonlinear processes and addresses these important forces. This model allows for the interaction and interdependence of six major components of the programme planning process. Furthermore, the planning wheel provides a macro and micro systems approach. The model incorporates internal and external forces that influence new economic development by capturing political, social, cultural, technological, and economic forces of the marketplace. The planning wheel offers promises in application in a variety of environments and circumstances. For example, it is especially valuable for workforce training programmes in emerging economies.

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Journal of Workplace Learning, vol. 10 no. 5
Type: Research Article
ISSN: 1366-5626

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Article
Publication date: 14 June 2022

Sreenadh Sreedharamalle, Sumalatha Baina and Srinivas A.N.S.

This paper aims to investigate the flow of two-layered non-Newtonian fluids with different viscosities in an axisymmetric elastic tube.

137

Abstract

Purpose

This paper aims to investigate the flow of two-layered non-Newtonian fluids with different viscosities in an axisymmetric elastic tube.

Design/methodology/approach

A mathematical model was considered for this study to describe the flow characteristics of two-layered non- Newtonian Jeffrey fluids in an elastic tube. Because Jeffrey fluid model is a better model for the description of physiological fluid motion. Further, this model is a significant generalization of Newtonian fluid model. Analytical expressions for flux, stream functions, velocities and interface velocity have been derived in terms of elastic parameters, inlet, outlet and external pressures. The effects of various pertinent parameters on the flow behavior have been studied.

Findings

The volumetric flow rate was calculated by different models of Mazumdar (1992) and Rubinow and Keller (1972); from this it was found that the flux of Jeffrey fluid is more in the case of Rubinow and Keller model than Mazumdar. A comparative study is made between single-fluid and two-fluid models of Jeffrey fluid flows and it was observed that more flux and higher velocities were observed in the case of two-fluid model rather than single-fluid model. Furthermore, when both the Jeffrey parameter tends to zero and ratios of viscosities and radii are unity, the results in this study agree with those of Rubinow and Keller (1972).

Originality/value

To describe the fluid flow in an elastic tube with two-layered systems, the models and solutions developed here are very important. These results will be highly suitable in analyzing the rheological characteristics of blood flow in a small blood vessel because of their elastic nature.

Details

World Journal of Engineering, vol. 20 no. 6
Type: Research Article
ISSN: 1708-5284

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Article
Publication date: 12 October 2017

A.M. Abd-Alla, S.M. Abo-Dahab and Abdullah Alsharif

The purpose of this paper is to study the peristaltic flow of a Jeffrey fluid in an asymmetric channel, subjected to gravity field and rotation in the presence of a magnetic…

121

Abstract

Purpose

The purpose of this paper is to study the peristaltic flow of a Jeffrey fluid in an asymmetric channel, subjected to gravity field and rotation in the presence of a magnetic field. The channel asymmetry is produced by choosing the peristaltic wave train on the walls to have different amplitude and phase. The flow is investigated in a wave frame of reference moving with the velocity of the wave. Involved problems are analyzed through long wavelength and low Reynolds number.

Design/methodology/approach

The analytical expressions for the pressure gradient, pressure rise, stream function, axial velocity and shear stress have been obtained. The effects of Hartmann number, the ratio of relaxation to retardation times, time-mean flow, rotation, the phase angle and the gravity field on the pressure gradient, pressure rise, streamline, axial velocity and shear stress are very pronounced and physically interpreted through graphical illustrations. Comparison was made with the results obtained in the asymmetric and symmetric channels.

Findings

The results indicate that the effect of the Hartmann number, the ratio of relaxation to retardation times, time-mean flow, rotation, the phase angle and the gravitational field are very pronounced in the phenomena.

Originality/value

In the present work, the authors investigate gravity field, and rotation through an asymmetric channel in the presence of a magnetic field has been analyzed. It also deals with the effect of the magnetic field and gravity field of peristaltic transport of a Jeffrey fluid in an asymmetric rotating channel.

Details

Multidiscipline Modeling in Materials and Structures, vol. 13 no. 4
Type: Research Article
ISSN: 1573-6105

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Article
Publication date: 13 December 2024

Ashvani Kumar, Anjali Bhardwaj and Dharmendra Tripathi

Surface properties (smooth or roughness) play a critical role in controlling the wettability, surface area and other physical and chemical properties like fluid flow behaviour…

21

Abstract

Purpose

Surface properties (smooth or roughness) play a critical role in controlling the wettability, surface area and other physical and chemical properties like fluid flow behaviour over the rough and smooth surfaces. It is reported that rough surfaces are offering more significant insights as compared to smooth surfaces. The purpose of this study is to examine the effects of surface roughness in the diverging channel on physiological fluid flows.

Design/methodology/approach

A mathematical formulation based on the conservation of mass and momentum equations is developed to derive exact solutions for the physical quantities under the assumption of low Reynolds numbers and long wavelengths, which are appropriate for biological transport scenarios.

Findings

The results reveal that an increase in surface roughness reduces axial velocity and volumetric flow rate while increasing pressure distribution and turbulence in skin friction.

Research limitations/implications

These findings offer valuable insights for biological flow analysis, highlighting the effects of surface roughness, non-uniformity of the channel and magnetic fields.

Practical implications

These findings are very much applicable for designing the pumping devices for transportation of the fluids in non-uniform channels.

Originality/value

This study examines the impact of surface roughness on the peristaltic pumping of viscoelastic (Jeffrey) fluids in diverging channels with transverse magnetic fields.

Details

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

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Article
Publication date: 4 September 2017

M. Kothandapani and V. Pushparaj

This paper aims to investigate the consequence of the combined impacts of an induced magnetic field and thermal radiation on peristaltic transport of a Carreau nanofluid in a…

116

Abstract

Purpose

This paper aims to investigate the consequence of the combined impacts of an induced magnetic field and thermal radiation on peristaltic transport of a Carreau nanofluid in a vertical tapered asymmetric channel. The model applied for the nanofluid comprises the effects of Brownian motion and thermophoresis.

Design/methodology/approach

The governing equations have been simplified under the widespread assumption of long-wavelength and low-Reynolds number approximations. The reduced coupled nonlinear equations of momentum and magnetic force function have also been solved analytically using the regular perturbation method.

Findings

The physical features of emerging parameters have been discussed by drawing the graphs of velocity, temperature, nanoparticle concentration profile, magnetic force function, current density, heat transfer coefficient and stream function. It has been realized that the magnetic force function is increased with the increase of Hartmann number, magnetic Reynolds number and mean flow rate.

Originality/value

It may be first paper in which the effect of induced magnetic field on peristaltic flow of non-Newtonian nanofluid in a tapered asymmetric channel has been studied.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 27 no. 9
Type: Research Article
ISSN: 0961-5539

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Article
Publication date: 6 October 2022

Meenakumari Ramamoorthy and Lakshminarayana Pallavarapu

The present work explores the influence of Hall and Ohmic heating effects on the convective peristaltic flow of a conducting Jeffrey nanofluid in an inclined porous asymmetric…

84

Abstract

Purpose

The present work explores the influence of Hall and Ohmic heating effects on the convective peristaltic flow of a conducting Jeffrey nanofluid in an inclined porous asymmetric channel with slip. Also, the authors investigated the impact of viscous dissipation, thermal radiation, heat generation/absorption and cross diffusion effects on the flow. Peristaltic flow has many industrial and physiological applications and most of the biofluids show the non-Newtonian fluid behaviour. Further, in a living body, several biofluids flow through different kinds of systems that are not symmetric, horizontal or vertical. The purpose of this paper is to address these issues.

Design/methodology/approach

The authors considered the flow of Jeffrey fluid which is generated by a sinusoidal wave propagating on the walls of an inclined asymmetric channel. The flow model is developed from the fixed frame to the wave frame. Finally, yield the nonlinear governing equations by applying the non-dimensional quantities with the assumptions of lengthy wave and negligible Reynolds number. The exact solution has been computed for the velocity and pressure gradient. The solutions for temperature and concentration are obtained by the regular perturbation technique.

Findings

Graphical analysis is made for the present results for different values of emerging parameters and explained clearly. It is noticed that the magnetic field enriches the temperature where it drops the fluid velocity. This work describes that the temperature field is decreasing due to the radiation but it is a rising function of temperature slip parameter. The temperature profile declines for growing values of the Hall parameter. The flow velocity diminishes for boosting values of the Darcy parameter. Further, the authors perceived that the concentration field reduces for large values of the chemical reaction parameter.

Originality/value

The authors validated and compared the results with the existing literature. This investigation will help to study some physiological systems, and heat transfer in peristaltic transport plays key role in medical treatments, so we ensure that these results are applicable in medical treatments like cancer therapy, drug delivery, etc.

Details

Multidiscipline Modeling in Materials and Structures, vol. 18 no. 6
Type: Research Article
ISSN: 1573-6105

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Article
Publication date: 1 October 2006

A. Mezrhab, H. Bouali, H. Amaoui and C. Abid

The purpose of this paper is to study the radiation‐natural convection interactions in a vertical divided vented channel. The effects of the surface emissivity, the vent opening…

374

Abstract

Purpose

The purpose of this paper is to study the radiation‐natural convection interactions in a vertical divided vented channel. The effects of the surface emissivity, the vent opening position and size on the heat transfer and the flow structures inside the channel were studied.

Design/methodology/approach

The governing differential equations are solved by a finite volume method, with adopting the SIMPLER algorithm for pressure‐velocity coupling. The view factors were determined by using a boundary elements approximation and a Monte Carlo method.

Findings

The effect of the radiation exchange is very important, it increases the average hot wall Nusselt number by more than 100 per cent. The contribution of the channel wall emissivity in the heat transfer is more important than that of the plate emissivity. The average hot wall Nusselt number increases with increasing the vent opening size, only in presence of the radiation exchange, and this increase is more pronounced, particularly when the vent opening is located near the channel inlet.

Research limitations/implications

The flow is assumed to be incompressible, laminar and two dimensional. The radiative surfaces are assumed diffuse‐grey. The working fluid, air, is considered as transparent with respect to the radiation.

Practical implications

The industrial applications of this study are solar collectors, thermal building, electronic cooling, aeronautics, chemical apparatus, nuclear engineering, etc.

Originality/value

In comparison to the preceding studies, the originality of this paper is the taking into account of the radiation exchange in a vented and divided channel.

Details

Engineering Computations, vol. 23 no. 7
Type: Research Article
ISSN: 0264-4401

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Article
Publication date: 4 August 2020

Mehmet Caner Akay and Hakan Temeltaş

Heterogeneous teams consisting of unmanned ground vehicles and unmanned aerial vehicles are being used for different types of missions such as surveillance, tracking and…

130

Abstract

Purpose

Heterogeneous teams consisting of unmanned ground vehicles and unmanned aerial vehicles are being used for different types of missions such as surveillance, tracking and exploration. Exploration missions with heterogeneous robot teams (HeRTs) should acquire a common map for understanding the surroundings better. The purpose of this paper is to provide a unique approach with cooperative use of agents that provides a well-detailed observation over the environment where challenging details and complex structures are involved. Also, this method is suitable for real-time applications and autonomous path planning for exploration.

Design/methodology/approach

Lidar odometry and mapping and various similarity metrics such as Shannon entropy, Kullback–Leibler divergence, Jeffrey divergence, K divergence, Topsoe divergence, Jensen–Shannon divergence and Jensen divergence are used to construct a common height map of the environment. Furthermore, the authors presented the layering method that provides more accuracy and a better understanding of the common map.

Findings

In summary, with the experiments, the authors observed features located beneath the trees or the roofed top areas and above them without any need for global positioning system signal. Additionally, a more effective common map that enables planning trajectories for both vehicles is obtained with the determined similarity metric and the layering method.

Originality/value

In this study, the authors present a unique solution that implements various entropy-based similarity metrics with the aim of constructing common maps of the environment with HeRTs. To create common maps, Shannon entropy–based similarity metrics can be used, as it is the only one that holds the chain rule of conditional probability precisely. Seven distinct similarity metrics are compared, and the most effective one is chosen for getting a more comprehensive and valid common map. Moreover, different from all the studies in literature, the layering method is used to compute the similarities of each local map obtained by a HeRT. This method also provides the accuracy of the merged common map, as robots’ sight of view prevents the same observations of the environment in features such as a roofed area or trees. This novel approach can also be used in global positioning system-denied and closed environments. The results are verified with experiments.

Details

Industrial Robot: the international journal of robotics research and application, vol. 47 no. 6
Type: Research Article
ISSN: 0143-991X

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Article
Publication date: 28 November 2018

Mohammadhossein Hajiyan, Shohel Mahmud, Mohammad Biglarbegian, Hussein A. Abdullah and A. Chamkha

The purpose of this paper is to investigate the convective heat transfer of magnetic nanofluid (MNF) inside a square enclosure under uniform magnetic fields considering…

194

Abstract

Purpose

The purpose of this paper is to investigate the convective heat transfer of magnetic nanofluid (MNF) inside a square enclosure under uniform magnetic fields considering nonlinearity of magnetic field-dependent thermal conductivity.

Design/methodology/approach

The properties of the MNF (Fe3O4+kerosene) were described by polynomial functions of magnetic field-dependent thermal conductivity. The effect of the transverse magnetic field (0 < H < 105), Hartmann Number (0 < Ha < 60), Rayleigh number (10 <Ra <105) and the solid volume fraction (0 < φ < 4.7%) on the heat transfer performance inside the enclosed space was examined. Continuity, momentum and energy equations were solved using the finite element method.

Findings

The results show that the Nusselt number increases when the Rayleigh number increases. In contrast, the convective heat transfer rate decreases when the Hartmann number increases due to the strong magnetic field which suppresses the buoyancy force. Also, a significant improvement in the heat transfer rate is observed when the magnetic field is applied and φ = 4.7% (I = 11.90%, I = 16.73%, I = 10.07% and I = 12.70%).

Research limitations/implications

The present numerical study was carried out for a steady, laminar and two-dimensional flow inside the square enclosure. Also, properties of the MNF are assumed to be constant (except thermal conductivity) under magnetic field.

Practical implications

The results can be used in thermal storage and cooling of electronic devices such as lithium-ion batteries during charging and discharging processes.

Originality/value

The accuracy of results and heat transfer enhancement having magnetic field-field-dependent thermal conductivity are noticeable. The results can be used for different applications to improve the heat transfer rate and enhance the efficiency of a system.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 29 no. 4
Type: Research Article
ISSN: 0961-5539

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Article
Publication date: 16 October 2017

A.M. Abd-Alla, S.M. Abo-Dahab and M. Elsagheer

The purpose of this paper is to predict the effects of magnetic field, heat and mass transfer and rotation on the peristaltic flow of an incompressible Newtonian fluid in a…

90

Abstract

Purpose

The purpose of this paper is to predict the effects of magnetic field, heat and mass transfer and rotation on the peristaltic flow of an incompressible Newtonian fluid in a channel with compliant walls. The whole system is in a rotating frame of reference.

Design/methodology/approach

The governing equations of two-dimensional fluid have been simplified under long wavelength and low Reynolds number approximation. The solutions are carried out for the stream function, temperature, concentration field, velocity and heat transfer coefficient.

Findings

The results indicate that the effects of permeability, magnetic field and rotation are very pronounced in the phenomena. Impacts of various involved parameters appearing in the solutions are carefully analyzed.

Originality/value

The effect of the concentration distribution, heat and mass transfer and rotation on the wave frame is analyzed theoretically and computed numerically. Numerical results are given and illustrated graphically in each case considered. A comparison was made with the results obtained in the presence and absence of rotation, magnetic field and heat and mass transfer.

Details

Multidiscipline Modeling in Materials and Structures, vol. 13 no. 4
Type: Research Article
ISSN: 1573-6105

Keywords

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