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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…

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. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 7 June 2023

Sara Armou, Mustapha Ait Hssain, Soufiane Nouari, Rachid Mir and Kaoutar Zine-Dine

The purpose of this study is to investigate the impact of varying baffle height and spacing distance on heat transfer and cooling performance of electronic components in a baffled…

Abstract

Purpose

The purpose of this study is to investigate the impact of varying baffle height and spacing distance on heat transfer and cooling performance of electronic components in a baffled horizontal channel, using a Cu-H2O nanofluid under mixed convection and laminar flow.

Design/methodology/approach

The mathematical model is two-dimensional and comprises a system of four governing equations, such as the conservation of continuity, momentum and energy. To obtain numerical solutions for these equations, the finite volume method was used for discretization. A validation process was performed by comparing this study’s results with those of previously published studies. The comparison revealed a close agreement. The numerical study was performed for a wide range of key parameters: The baffle height (0 ≤ h ≤ 0.7), the spacing distance between baffle and blocks (0.25 ≤ w ≤ 3), the Grashof and Reynolds numbers are kept equal to 104 and 75, respectively, the channel aspect ratio is L/H = 10, and the volume fraction of Cu nanoparticles is fixed at φ = 5%.

Findings

The results of the study reveal a significant improvement in heat transfer in terms of total Nusselt number of the top and bottom hot components, which exhibited an improvement of 16.89% and 17.23% when the baffle height increases from h = 0 to h = 0.7. Additionally, the study found that reducing the distance between the baffle and the electronic components up to a certain limit can improve the heat transfer rate. Therefore, the optimal height of the baffle was found to be no lower than 0.6, and the recommended distance between the heaters and the baffle was 0.5.

Originality/value

This study provides valuable insights into the optimization of the design of baffled channels for improved heat transfer performance. The findings of study can be used to improve heat exchangers and cooling systems in various applications. The use of Cu-H2O nanofluid under mixed convection and laminar flow conditions in channel with baffle and electronic components is also unique, making this study an original contribution to the field.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 34 no. 2
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 26 September 2023

Mahmoud Abou Kamar, Azza Maher, Islam Elbayoumi Salem and Ahmed Mohamed Elbaz

This study used an integrated model that incorporates the Technology Acceptance Model (TAM) and the Theory of Planned Behaviour (TPB) to empirically investigate how…

Abstract

Purpose

This study used an integrated model that incorporates the Technology Acceptance Model (TAM) and the Theory of Planned Behaviour (TPB) to empirically investigate how eco-gamification stimulates users' sustainability knowledge and, consequently, their pro-sustainable intentions through the mediating roles of sustainable knowledge and psychological and social norms. Thus, the study aims to examine users'’ experiences with the JouleBug app, which is designed to encourage users to complete at least one daily green task.

Design/methodology/approach

After a trial period of two weeks, a total of 360 participants completed the post-game survey during the research process.

Findings

The findings from the structural equation modeling and data analysis indicated a good fit for the model. The findings demonstrate that usefulness, ease of use and enjoyment of eco-gamification enrich users' sustainability knowledge, which, in turn, strongly influences their pro-sustainable intentions. According to the findings, the three factors of TPB have a significant impact on users' pro-sustainability intentions. Both sustainable knowledge and social cues play mediating roles in such relationships.

Practical implications

This study advocates that eco-gamification can be used as a platform to modify tourists’ pro-sustainability intentions in emerging tourism and technology destinations such as Egypt. Hence, this study offers significant information to tourism planners and other stakeholders on tourists’ behavioural intentions.

Originality/value

This study examined the effectiveness of an integrated model of TAM and TBP in predicting tourists’ intentions to use eco-gamification to improve the sustainability of tourist destinations.

目的

本研究采用结合技术接受模型(TAM)和计划行为理论(TPB)的综合模型, 旨在探究生态游戏化如何提升用户对可持续性的认知, 从而影响他们支持环保行为的意愿。通过研究可持续性知识以及心理和社会规范在其中的中介作用来实现这一目标。因此, 本研究调查了用户使用JouleBug应用程序的体验, 该应用程序旨在鼓励用户每天完成至少一个环保任务。

设计/方法/步骤

在为期两周的试验期后, 共有360名参与者在研究过程中完成了后测问卷调查。

研究结果

通过结构方程模型和数据分析, 研究结果表明模型拟合良好。研究发现, 生态游戏化的实用性、易用性和乐趣能够丰富用户的可持续性知识, 从而强烈影响他们支持可持续性的意愿。研究结果还显示, 计划行为理论(TPB)的三个因素对用户的支持可持续性意愿有显著影响。可持续性知识和社会提示在这些关系中发挥着中介作用。

实际意义

本研究主张, 生态游戏化可以作为一个平台, 用于引导游客在埃及等新兴旅游和科技目的地中支持可持续性的意愿。因此, 该研究为旅游规划者和其他利益相关者提供了有关游客行为意向的重要信息。

创新性/价值

本研究考察了TAM和TPB综合模型在预测游客使用生态游戏化改善旅游目的地可持续性意愿方面的有效性。

Finalidad

Este estudio utilizó un modelo integrado que combina el Modelo de Aceptación Tecnológica (TAM) y la Teoría del Comportamiento Planificado (TPB) para investigar cómo la eco-gamificación aumenta el conocimiento de los usuarios sobre la sostenibilidad y, en consecuencia, sus intenciones para actuar favorablemente en el medio ambiente. Esto se logró analizando cómo el conocimiento sostenible y las normas psicológicas y sociales actuaban como mediadores. Para ello, la investigación examina las experiencias de los usuarios con la aplicación JouleBug, diseñada para fomentar que los usuarios realicen al menos una tarea verde diaria.

Diseño/metodología/enfoque

Tras un período de prueba de dos semanas, un total de 360 participantes completaron la encuesta posterior al juego durante el proceso de investigación.

Resultados

Los resultados del modelo de ecuaciones estructurales y análisis de datos indicaron un buen ajuste del modelo. Los resultaros evidencian que la utilidad, facilidad de uso y disfrute de la eco-gamificación enriquecen el conocimiento de sostenibilidad de los usuarios y, a su vez, influye significativamente en sus intenciones pro-sostenibilidad. Conforme a los resultados, los tres factores de la TPB tienen un impacto significativo en las intenciones pro-sostenibilidad de los usuarios. Tanto el conocimiento sostenible como las señales sociales desempeñan roles mediadores en estas relaciones.

Implicaciones prácticas

Este estudio aboga por el uso de la eco-gamificación como una plataforma para modificar las intenciones pro-sostenibilidad de los turistas en destinos emergentes de turismo y tecnología, como Egipto. Por tanto, esta investigación proporciona información significativa para los planificadores de turismo y otros interesados en las intenciones conductuales de los turistas.

Originalidad/valor

Este estudio examinó la eficacia de un modelo integrado de TAM y TPB para predecir las intenciones de los turistas de utilizar la eco-gamificación para mejorar la sostenibilidad de los destinos turísticos.

Article
Publication date: 29 January 2024

Karam Mansour Ghazi, Islam Elbayoumi Salem, Hesham Dar and Ahmed Mohamed Elbaz

The purpose of this study was to examine the impact of strategic leadership (SL) on business operational resilience (OR) in the hotel industry in Egypt, namely, during and after…

Abstract

Purpose

The purpose of this study was to examine the impact of strategic leadership (SL) on business operational resilience (OR) in the hotel industry in Egypt, namely, during and after the pandemic. This investigation also aimed to explore the mediating function of crisis response strategies (CRSs) and organisational e-readiness (Oe-R) in this relationship.

Design/methodology/approach

The researchers conducted a cross-sectional study using a questionnaire as the primary data collection method. Using partial least squares structural equation simulation (PLS-SEM), the study used a comprehensive sample that targets the general managers of all five-star hotels in Egypt.

Findings

Results indicated that SL has a positive impact on CRSs and Oe-R. Furthermore, the results reveal a positive influence of Oe-R on both CRSs and hotel OR. On the other hand, CRSs do not influence hotel OR. The findings showed that CRSs fully mediate the link between SL and OR. However, CRSs do not serve as a mediator between Oe-R and OR. Furthermore, the findings showed that Oe-R partially mediates the link between SL and both OR and CRSs.

Practical implications

The study yields unique and valuable theoretical and practical insights to guide hotel leaders and managers towards adaptive recovery and resilience in turbulent and crisis-ridden environments by demonstrating that the combined mediating function of CRS and Oe-R is more effective in strengthening the relationship between SL and OR.

Originality/value

This study represents a pioneering investigation that establishes a correlation between SL and OR, either through direct or indirect means. The research examines the involvement of CRSs and Oe-R as collaborative mediators in this relationship. Previous studies undertaken in the hotel industry and service sector have not investigated this specific element.

Details

International Journal of Contemporary Hospitality Management, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0959-6119

Keywords

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