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Article
Publication date: 28 October 2013

Lelanie Smith, Oliver Oxtoby, A. Malan and Josua Meyer

– The purpose of this paper is to introduce a unique technique to couple the two-integral boundary layer solutions to a generic inviscid solver in an iterative fashion.

Abstract

Purpose

The purpose of this paper is to introduce a unique technique to couple the two-integral boundary layer solutions to a generic inviscid solver in an iterative fashion.

Design/methodology/approach

The boundary layer solution is obtained using the two-integral method to solve displacement thickness point by point with a local Newton method, at a fraction of the cost of a conventional mesh-based, full viscous solution. The boundary layer solution is coupled with an existing inviscid solver. Coupling occurs by moving the wall to a streamline at the computed boundary layer thickness and treating it as a slip boundary, then solving the flow again and iterating. The Goldstein singularity present when solving boundary layer equations is overcome by solving an auxiliary velocity equation along with the displacement thickness.

Findings

The proposed method obtained favourable results when compared with the analytical solutions for flat and inclined plates. Further, it was applied to modelling the flow around a NACA0012 airfoil and yielded results similar to those of the widely used XFOIL code.

Originality/value

A unique method is proposed for coupling of the boundary layer solution to the inviscid flow. Rather than the traditional transpiration boundary condition, mesh movement is employed to simulate the boundary layer thickness in a more physically meaningful way. Further, a new auxiliary velocity equation is presented to circumvent the Goldstein singularity.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 23 no. 8
Type: Research Article
ISSN: 0961-5539

Keywords

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Article
Publication date: 1 February 1996

C. Shu, Y.T. Chew, B.C. Khoo and K.S. Yeo

The global methods of generalized differential quadrature (GDQ) andgeneralized integral quadrature (GIQ) are applied to solve three‐dimensional,incompressible, laminar…

Abstract

The global methods of generalized differential quadrature (GDQ) and generalized integral quadrature (GIQ) are applied to solve three‐dimensional, incompressible, laminar boundary layer equations. The streamwise and crosswise velocity components are taken as the dependent variables. The normal velocity is obtained by integrating the continuity equation along the normal direction where the integral is approximated by GIQ approach with high order of accuracy. All the spatial derivatives are discretized by a GDQ scheme. After spatial discretization, the resultant ordinary differential equations are solved by the 4‐stage Runge—Katta scheme. Application of GDQ—GIQ approach to a test problem demonstrated that accurate numerical results can be obtained using just a few grid points.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 6 no. 2
Type: Research Article
ISSN: 0961-5539

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Article
Publication date: 15 February 2020

Yunpeng Wang and Roger E. Khayat

The purpose of this study is to examine theoretically the axisymmetric flow of a steady free-surface jet emerging from a tube for high inertia flow and moderate surface…

Abstract

Purpose

The purpose of this study is to examine theoretically the axisymmetric flow of a steady free-surface jet emerging from a tube for high inertia flow and moderate surface tension effect.

Design/methodology/approach

The method of matched asymptotic expansion is used to explore the rich dynamics near the exit where a stress singularity occurs. A boundary layer approach is also proposed to capture the flow further downstream where the free surface layer has grown significantly.

Findings

The jet is found to always contract near the tube exit. In contrast to existing numerical studies, the author explores the strength of upstream influence and the flow in the wall layer, resulting from jet contraction. This influence becomes particularly evident from the nonlinear pressure dependence on the upstream distance, as well as the pressure undershoot and overshoot at the exit for weak and strong gravity levels, respectively. The approach is validated against existing experimental and numerical data for the jet profile and centerline velocity where good agreement is obtained. Far from the exit, the author shows how the solution in the diffusive region can be matched to the inviscid far solution, providing the desired appropriate initial condition for the inviscid far flow solution. The location, at which the velocity becomes uniform across the jet, depends strongly on the gravity level and exhibits a non-monotonic behavior with respect to gravity and applied pressure gradient. The author finds that under weak gravity, surface tension has little influence on the final jet radius. The work is a crucial supplement to the existing numerical literature.

Originality/value

Given the presence of the stress singularity at the exit, the work constitutes a superior alternative to a computational approach where the singularity is typically and inaccurately smoothed over. In contrast, in the present study, the singularity is entirely circumvented. Moreover, the flow details are better elucidated, and the various scales involved in different regions are better identified.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 30 no. 10
Type: Research Article
ISSN: 0961-5539

Keywords

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Article
Publication date: 8 January 2018

Hounaida El Jurdi and Sandra Smith

This research aims to draw on social identity theory (SIT) and social comparison theory (SCT) to examine how social and cultural contexts influence the construction and…

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Abstract

Purpose

This research aims to draw on social identity theory (SIT) and social comparison theory (SCT) to examine how social and cultural contexts influence the construction and pursuit of beauty ideals.

Design/methodology/approach

Sixteen Lebanese women aged between 18 and 45, from a range of backgrounds, were recruited for the purpose of this research. Interview questions probed the respondents’ female beauty ideals in relation to themselves and others. Photo-elicitation was used to facilitate and enrich each discussion.

Findings

The pursuit of beauty involves rich processes and is motivated by the search for an authentic self. Participants construct and pursue beauty ideals by mirroring views of their national identity through conformity, identification and subversion.

Practical implications

The pursuit of beauty is influenced not only by global media and celebrity culture but also by how respondents conceptualize their national identity. Beauty consumption serves two opposing functions in identity construction: social membership and distinction. Beauty, like fashion, serves as an indicator of taste that simultaneously includes the singularity and subjectivity of individual tastes.

Originality/value

This study extends research on the pursuit and consumption of beauty in several ways: it is situated in a non-western cultural context, it illustrates the usefulness of SCT and SIT in understanding beauty consumption and it highlights the role of mirroring processes in identity construction and beauty consumptive practices.

Details

Journal of Consumer Marketing, vol. 35 no. 1
Type: Research Article
ISSN: 0736-3761

Keywords

Open Access
Article
Publication date: 6 June 2018

Christophe Schinckus and Cinla Akdere

How a micro-founded discipline such as economics could deal with the increasing global economic reality? This question has been asked frequently since the last economic…

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1412

Abstract

Purpose

How a micro-founded discipline such as economics could deal with the increasing global economic reality? This question has been asked frequently since the last economic crisis that appeared in 2008. In this challenging context, some commentators have turned their attention to a new area of knowledge coming from physics: econophysics which mainly focuses on a macro-analysis of economic systems. By showing that concepts used by econophysicists are consistent with an existing economic knowledge (developed by J.S. Mill), the purpose of this paper is to claim that an interdisciplinary perspective is possible between these two communities.

Design/methodology/approach

The authors propose a historical and conceptual analysis of the key concept of emergence to emphasize the potential bridge between econophysics and economics.

Findings

Six methodological arguments will be developed in order to show the existence of conceptual bridges as a necessary condition for the elaboration of a common language between economists and econophysics which would not be superfluous, in this challenging context, to clarify the growing complexity of economic phenomena.

Originality/value

Although the economics and econophysics study same the complex economic phenomena, very few collaborations exist between them. This paper paves a conceptual/methodological path for more collaboration between the two fields.

Details

Journal of Asian Business and Economic Studies, vol. 25 no. 1
Type: Research Article
ISSN: 2515-964X

Keywords

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Book part
Publication date: 25 November 2019

Lynne G. Zucker and Oliver Schilke

In this chapter, the authors weave together a set of ideas that lead us closer to a more general institutional theory – one that embraces multiple levels of analysis…

Abstract

In this chapter, the authors weave together a set of ideas that lead us closer to a more general institutional theory – one that embraces multiple levels of analysis, including the micro-level. The authors build on the roots of micro-institutional thought – including phenomenological and ethnomethodological underpinnings – as well as very active, social-psychological research areas that address key mechanisms in institutionalization. Among these, the authors discuss the important roles of legitimacy, trust, social influence, and routines. There is great promise for micro-institutional inquiry to make an integral contribution to institutional theory by bringing processes and people back in.

Details

Microfoundations of Institutions
Type: Book
ISBN: 978-1-78769-127-8

Keywords

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Article
Publication date: 1 May 1948

I SHOULD like first to say how much I appreciate the honour of being invited to deliver the Wright Brothers Lecture. To anyone whose work is associated in any way with the…

Abstract

I SHOULD like first to say how much I appreciate the honour of being invited to deliver the Wright Brothers Lecture. To anyone whose work is associated in any way with the aeronautical sciences, it must be a source of pride and gratification to be invited to be a chief participant in one of the greatest occasions in the world of aeronautical research, an occasion designed in honour of the two great pioneers, Wilbur and Orville Wright. In my own case these feelings are shared with a feeling of humility and of my own unworthiness for the task.

Details

Aircraft Engineering and Aerospace Technology, vol. 20 no. 5
Type: Research Article
ISSN: 0002-2667

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Article
Publication date: 8 August 2018

Federico del Castillo

In the broad context of Uruguay’s police reform, the Ministry of Interior is implementing a problem-oriented policing (POP) program in Montevideo, Uruguay’s capital city…

Abstract

Purpose

In the broad context of Uruguay’s police reform, the Ministry of Interior is implementing a problem-oriented policing (POP) program in Montevideo, Uruguay’s capital city. The purpose of this paper is to examine the obstacles confronted by this program over its implementation.

Design/methodology/approach

Data were collected through 20 semi-structured interviews conducted with members of the Uruguay National Police selected via purposeful sampling. The study relies on a grounded theory approach. Findings were interpreted based on five categories of analysis.

Findings

Findings point at obstacles confronted by the program associated with contextual organizational factors, a general misunderstanding of POP, leadership, resistance and motivation, and availability and sufficiency of resources.

Originality/value

Although POP has been implemented in a variety of settings, it is still rare in Latin America. As a consequence, research on POP is limited in this region. This study adds to the small but growing body of literature on the police reform in Latin America, and at the same time, is one the few pieces of research on the police reform in Uruguay.

Details

Policing: An International Journal, vol. 42 no. 3
Type: Research Article
ISSN: 1363-951X

Keywords

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Book part
Publication date: 19 May 2009

Obadia Lionel

This chapter considers the importation of brand images, a key concept in marketing studies, within anthropological approaches to culture and consumption. It does so…

Abstract

This chapter considers the importation of brand images, a key concept in marketing studies, within anthropological approaches to culture and consumption. It does so through examining modes of cultural valuation toward “Made in China” products on the part of consumers. Following theoretical lines recently established by anthropologists in the study of culture, commodification, and consumption in global settings, and their emphasis upon culture as a label for goods, it also brings into the discussion issues in geopolitics and ethnicity, especially from the viewpoint of ethnographic evidence collected in France and Nepal. “Made in China” products are enmeshed in complex, intermingling, and conflicting imaginations of the Other, brand images, and are associated with the underlying social logic of consumption or avoidance of consumption, often paradoxical, but intelligible in both broad-ranging and local contexts.

Details

Economic Development, Integration, and Morality in Asia and the Americas
Type: Book
ISBN: 978-1-84855-542-6

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Article
Publication date: 3 July 2017

Jerzy Golebiowski and Marek Zareba

The purpose of this article is investigating the impact of the spatially variable heat transfer coefficient on the thermal field in the double insulated wire.

Abstract

Purpose

The purpose of this article is investigating the impact of the spatially variable heat transfer coefficient on the thermal field in the double insulated wire.

Design/methodology/approach

The effect of the air boundary layer was modelled by means of changing the total heat transfer coefficient on the external perimeter of the wire. This leads to an elliptical boundary problem with Hankel’s condition dependent on the angular coordinate. The eigenfunctions of the problem were determined analytically. On the other hand, the unknown coefficients of eigenfunctions and the constants were calculated numerically by solving a respective system of algebraic equations. The steady state current rating was determined with an iterative method.

Findings

By means of the presented method, the thermal field distribution deprived of axial symmetry in the double insulated wire was determined. The obtained results have good physical interpretation and were verified with the finite element method (by means of NISA v. 16 software). The determined values of the steady-state current rating were compared with those calculated by means of the equivalent heat transfer coefficient method and the International Electrotechnical Commission (IEC) standard.

Research limitations/implications

The method is applied to analyse scalar fields in layered cylindrical structures. This could be expanded to the case of a wire of any number of insulation layers. What is more, one could also consider heat sources without axial symmetry and located within the external area.

Originality/value

The analytical method of determining a thermal field deprived of axial symmetry in heterogeneous cylindrical system (the wire composed of three different materials) was developed.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 36 no. 4
Type: Research Article
ISSN: 0332-1649

Keywords

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