Search results

1 – 10 of 102
Per page
102050
Citations:
Loading...
Access Restricted. View access options
Article
Publication date: 1 January 1969

B. Gehri

Le problème de la formation professionnelle mais également celui de l'éducation et de la formation culturelle ne sauraient échapper à l'emprise de la société dans laquelle nous…

35

Abstract

Le problème de la formation professionnelle mais également celui de l'éducation et de la formation culturelle ne sauraient échapper à l'emprise de la société dans laquelle nous vivons actuellement. L'Institut International de Glion, fondé il y a maintenant plus de 6 ans, s'est spécialement attaché à la création d'un type d'enseignement qui tiendrait largement compte de ces éléments, eux‐mêmes rattachés aux changements structurels et quantitatifs qu'a fait subir l'évolution du tourisme à toutes les formes d'hébergement. C'est une des raisons pour lesquelles l'enseignement proposé à Glion se différencie, dans de très nombreux secteurs, de la formule qui semblerait classique et qui est celle que nous rencontrons dans les écoles professionnelles hôtelières de la plupart des pays européens et du monde.

Details

The Tourist Review, vol. 24 no. 1
Type: Research Article
ISSN: 0251-3102

Access Restricted. View access options
Article
Publication date: 10 March 2023

Hung Truong, Abderahmane Marouf, Alain Gehri, Jan Vos, Marianna Braza and Yannick Hoarau

This study aims to investigate the physical mechanisms of the use of active flow control (AFC) for a high-lift wing-flap configuration.

126

Abstract

Purpose

This study aims to investigate the physical mechanisms of the use of active flow control (AFC) for a high-lift wing-flap configuration.

Design/methodology/approach

By means of high-fidelity numerical simulations, the flow dynamics around a high-lift wing-flap system at high Reynolds number (Re/c = 4.6 million) is studied. Adapted turbulence models based on the URANS approach are used to capture the flow separation and the subsequent development of coherent structures. The present study focuses on the use of AFC using a synthetic jet known as zero-net-mass-flux (ZNMF) using the blowing–suction approach. Different parameters (geometry, frequency and velocity) of a ZNMF placed at the cambered flap’s chord are optimized to obtain the most efficient parameter settings to suppress the flow separation.

Findings

A synthetic jet with the optimal shape and orientation enforces the flow reattachment on the wing-flap surface. This leads to an improvement of the aerodynamic performance of the system. The wake thickness was reduced by 30%, and an increase of 17.6% in lift-to-drag ratio was obtained. Concerning the ZNMF location, they should be installed upstream of the separation point to achieve the best performance.

Originality/value

The effectiveness of ZNMF devices integrated on a high-lift wing-flap configuration was studied in real flight conditions at high Reynolds number. A detailed analysis of the wake dynamics explains how AFC forces the reattachment of the boundary layer and attenuates the predominant wake instabilities up to −20 dB.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 33 no. 4
Type: Research Article
ISSN: 0961-5539

Keywords

Access Restricted. View access options
Article
Publication date: 5 October 2012

Heng Li, H.L. Guo, S.C.W. Kong and Zhen Chen

Due to the increasing complexity of curved roof surface design and the inadequate optimisation algorithms in design software, the optimisation of curved roof surface design needs…

291

Abstract

Purpose

Due to the increasing complexity of curved roof surface design and the inadequate optimisation algorithms in design software, the optimisation of curved roof surface design needs to be studied further. The purpose of this paper is to develop an alternative approach to improve the efficiency and effectiveness of curved roof surface design of buildings.

Design/methodology/approach

To achieve the purpose, an optimisation method/tool is developed through reviewing the application of CATIA and integrating genetic algorithm with CATIA; and the effectiveness to perform the GA‐based optimisation method is demonstrated by using a real‐life case study. Furthermore, a comparison among different optimisation algorithms currently available in the CATIA system is conducted.

Findings

Through the case study and the comparison, it is found that the GA‐based method can improve the performance of optimisation for curved roof surface design in the CATIA system; however, further research work is required for the best global optimisation result.

Originality/value

The paper proposes an optimisation method for curved roof surface design through integrating genetic algorithm with CATIA. This method improves the current method of curved roof surface design.

Details

Journal of Engineering, Design and Technology, vol. 10 no. 3
Type: Research Article
ISSN: 1726-0531

Keywords

Access Restricted. View access options
Article
Publication date: 1 January 1976

Beat R. Kunz

Programme provisoire du 26e Congrès AIEST du 5 au 12 septembre 1976, à Athènes. Sujet général: Les problèmes de management dans le domaine du tourisme

14

Abstract

Programme provisoire du 26e Congrès AIEST du 5 au 12 septembre 1976, à Athènes. Sujet général: Les problèmes de management dans le domaine du tourisme

Details

The Tourist Review, vol. 31 no. 1
Type: Research Article
ISSN: 0251-3102

Access Restricted. View access options
Article
Publication date: 1 February 1978

Nous rappelons les membres AIEST de remettre leur fiche d'inscription au 28e Congrès AIEST du 17 au 24 septembre 1978 au Secrétariat général jusqu'au 31 juillet 1978. Les membres…

20

Abstract

Nous rappelons les membres AIEST de remettre leur fiche d'inscription au 28e Congrès AIEST du 17 au 24 septembre 1978 au Secrétariat général jusqu'au 31 juillet 1978. Les membres ayant l'intention de présenter un rapport spécial sont priés de le remettre en 3 exemplaires dactylographiés selon le modèle type également jusqu'au 31 juillet 1978.

Details

The Tourist Review, vol. 33 no. 2
Type: Research Article
ISSN: 0251-3102

Access Restricted. View access options
Article
Publication date: 1 April 1971

Ci‐après, nous publions — le programme du 21e Congrès de l'AIEST — Association internationale d'experts scientifiques du tourisme,

34

Abstract

Ci‐après, nous publions — le programme du 21e Congrès de l'AIEST — Association internationale d'experts scientifiques du tourisme,

Details

The Tourist Review, vol. 26 no. 4
Type: Research Article
ISSN: 0251-3102

Access Restricted. View access options
Article
Publication date: 2 February 2023

Abderahmane Marouf, Yannick Hoarau, Jean-François Rouchon and Marianna Braza

This study aims to investigate the effects of electroactive morphing on the Airbus A320 Reduced Scale prototype of the H2020 N° 723402 European Research project smart morphing and…

88

Abstract

Purpose

This study aims to investigate the effects of electroactive morphing on the Airbus A320 Reduced Scale prototype of the H2020 N° 723402 European Research project smart morphing and sensing (SMS) for aeronautical configurations [1],[2].

Design/methodology/approach

The flow regimes correspond to low subsonic take-off conditions. The morphing is applied through the vibration and slight deformation of the near trailing edge region; respecting the way, this actuation has been applied on the experimental prototype using micro fibre composite actuators. Optimal frequency range has been used, associated with low amplitudes of deformation with the Arbitrary Lagrangian Eulerian methodology. This study used an adapted turbulence modelling with the organised eddy simulation (OES) as well as a hybrid approach delayed detached eddy simulation – with embedded OES (DDES–OES), able to sensitise and keep up the coherent structures development.

Findings

The morphing at an optimal frequency (300 Hz) and amplitude (0.7 mm), applied on a length (3.5 cm) near the trailing edge, has been studied at Reynolds number 1 million and incidence of 10°. The effects on the main flow instabilities and on the turbulent vortex structures are analysed using proper orthogonal decomposition. A modification of the wake structures and a formation of organised rows of vortices along the shear layer are obtained. This leads to a quasi-two-dimensional wake, benefits on the aerodynamic performance and a decrease of the frequency peaks in the spectrum, corresponding to an attenuation of the coherent structures.

Originality/value

This study provides a fundamental understanding of how the actuation modifies the coherent and turbulent vortex structures around the wing and in the wake.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 33 no. 4
Type: Research Article
ISSN: 0961-5539

Keywords

Access Restricted. View access options
Article
Publication date: 2 January 2020

Abderahmane Marouf, Yannick Bmegaptche Tekap, Nikolaos Simiriotis, Jean-Baptiste Tô, Jean-François Rouchon, Yannick Hoarau and Marianna Braza

The purpose of this study illustrates the morphing effects around a large-scale high-lift configuration of the Airbus A320 with two elements airfoil-flap in the take-off position…

172

Abstract

Purpose

The purpose of this study illustrates the morphing effects around a large-scale high-lift configuration of the Airbus A320 with two elements airfoil-flap in the take-off position. The flow around the airfoil-flap and the near wake are analysed in the static case and under time-dependent vibration of the flap trailing-edge known as the dynamic morphing.

Design/methodology/approach

Experimental results obtained in the subsonic wind tunnel S1 of Institut de Mécanique des Fluides de Toulouse of a single wing are discussed with high-fidelity numerical results obtained by using the Navier–Stokes multi-block (NSMB) code with advanced turbulent modelling able to capture the predominant instabilities and coherent structure dynamics. An explanation of the dynamic time-dependent grid deformation is provided, which is used in the NSMB code to simulate the flap’s trailing-edge deformation in the morphing configuration. Finally, power spectral density is performed to reveal the coherent wake structures and their modification because of the morphing.

Findings

Frequency of vibration and amplitude of deformation effects are investigated for different morphing cases. Optimal morphing regions at a specific frequency and a slight deformation were able to attenuate the predominant natural shear-layer frequency and to considerably decrease the width of the von Kármán vortices with a simultaneous increase of aerodynamic performances.

Originality/value

The new concept of future morphed wings is proposed for a large scale A320 prototype at the take-off position. The dynamic morphing of the flap’s trailing-edge is simulated for the first time for high-lift two-element configuration. In addition, the wake analysis performed helped to show the turbulent structures according to the organised eddy simulation model.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 31 no. 2
Type: Research Article
ISSN: 0961-5539

Keywords

Access Restricted. View access options
Article
Publication date: 27 February 2024

Jacques Abou Khalil, César Jiménez Navarro, Rami El Jeaid, Abderahmane Marouf, Rajaa El Akoury, Yannick Hoarau, Jean-François Rouchon and Marianna Braza

This study aims to investigate the morphing concepts able to manipulate the dynamics of the downstream unsteadiness in the separated shear layers and, in the wake, be able to…

133

Abstract

Purpose

This study aims to investigate the morphing concepts able to manipulate the dynamics of the downstream unsteadiness in the separated shear layers and, in the wake, be able to modify the upstream shock–boundary layer interaction (SBLI) around an A320 morphing prototype to control these instabilities, with emphasis to the attenuation or even suppression of the transonic buffet. The modification of the aerodynamic performances according to a large parametric study carried out at Reynolds number of 4.5 × 106, Mach number of 0.78 and various angles of attack in the range of (0, 2.4)° according to two morphing concepts (travelling waves and trailing edge vibration) are discussed, and the final benefits in aerodynamic performance increase are evaluated.

Design/methodology/approach

This article examines through high fidelity (Hi-Fi) numerical simulation the effects of the trailing edge (TE) actuation and of travelling waves along a specific area of the suction side starting from practically the most downstream position of the shock wave motion according to the buffet and extending up to nearly the TE. The present paper studies through spectral analysis the coherent structures development in the near wake and the comparison of the aerodynamic forces to the non-actuated case. Thus, the physical mechanisms of the morphing leading to the increase of the lift-to-drag ratio and the drag and noise sources reduction are identified.

Findings

This study investigates the influence of shear-layer and near-wake vortices on the SBLI around an A320 aerofoil and attenuation of the related instabilities thanks to novel morphing: travelling waves generated along the suction side and trailing-edge vibration. A drag reduction of 14% and a lift-to-drag increase in the order of 8% are obtained. The morphing has shown a lift increase in the range of (1.8, 2.5)% for angle of attack of 1.8° and 2.4°, where a significant lift increase of 7.7% is obtained for the angle of incidence of 0° with a drag reduction of 3.66% yielding an aerodynamic efficiency of 11.8%.

Originality/value

This paper presents results of morphing A320 aerofoil, with a chord of 70cm and subjected to two actuation kinds, original in the state of the art at M = 0.78 and Re = 4.5 million. These Hi-Fi simulations are rather rare; a majority of existing ones concern smaller dimensions. This study showed for the first time a modified buffet mode, displaying periodic high-lift “plateaus” interspersed by shorter lift-decrease intervals. Through trailing-edge vibration, this pattern is modified towards a sinusoidal-like buffet, with a considerable amplitude decrease. Lock-in of buffet frequency to the actuation is obtained, leading to this amplitude reduction and a drastic aerodynamic performance increase.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 34 no. 7
Type: Research Article
ISSN: 0961-5539

Keywords

Access Restricted. View access options
Book part
Publication date: 16 May 2013

Gerardo del Cerro Santamaría

This chapter outlines and explains the development of the Abandoibarra megaproject, focusing in particular on the key role of the Bilbao Ría 2000 – an innovative cross…

Abstract

This chapter outlines and explains the development of the Abandoibarra megaproject, focusing in particular on the key role of the Bilbao Ría 2000 – an innovative cross institution, public–private partnership, responsible for coordinating the transfer of land between public and private agents. The chapter critically assesses the impact of the Guggenheim Museum Bilbao, the centerpiece in the Abandoibarra scheme. The narrative is based on fieldwork conducted by the author in the city of Bilbao. The chapter utilizes scholarly research, official sources, and reports in the news media to support the arguments. The chapter questions the viability of revitalization schemes based on urban megaprojects. Applying some of the elements in the revitalization mix to most cities may be unavoidable due to rapid and acritical adoption of policy discourses from center to periphery, but expecting to replicate one city's success in another context may prove extremely hard. The motivations of the Basque political elite to attract a Guggenheim museum go beyond the potential (and we might add, limited) urban regeneration benefits of a building, and can only be understood within the political context of the Basque Country and its relations with Spain. The case of Bilbao's revitalization has attracted significant attention as of late. This chapter uncovers the key issues surrounding Bilbao's transformation and puts the process in the context of capitalist globalization and the formation of globalizing cities.

Details

Urban Megaprojects: A Worldwide View
Type: Book
ISBN: 978-1-78190-593-7

Keywords

1 – 10 of 102
Per page
102050