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Article
Publication date: 19 February 2024

Xiang Shen, Kai Zeng, Liming Yang, Chengyong Zhu and Laurent Dala

This paper aims to study passive control techniques for transonic flow over a backward-facing step (BFS) using square-lobed trailing edges. The study investigates the efficacy of…

Abstract

Purpose

This paper aims to study passive control techniques for transonic flow over a backward-facing step (BFS) using square-lobed trailing edges. The study investigates the efficacy of upward and downward lobe patterns, different lobe widths and deflection angles on flow separation, aiming for a deeper understanding of the flow physics behind the passive flow control system.

Design/methodology/approach

Large Eddy Simulation and Reynolds-averaged Navier–Stokes were used to evaluate the results of the study. The research explores the impact of upward and downward patterns of lobes on flow separation through the effects of different lobe widths and deflection angles. Numerical methods are used to analyse the behaviour of transonic flow over BFS and compared it to existing experimental results.

Findings

The square-lobed trailing edges significantly enhance the reduction of mean reattachment length by up to 80%. At Ma = 0.8, the up-downward configuration demonstrates increased effectiveness in reducing the root mean square of pressure fluctuations at a proximity of 5-step height in the wake region, with a reduction of 50%, while the flat-downward configuration proves to be more efficient in reducing the root mean square of pressure fluctuations at a proximity of 1-step height in the near wake region, achieving a reduction of 71%. Furthermore, the study shows that the up-downward configuration triggers early spanwise velocity fluctuations, whereas the standalone flat-downward configuration displays less intense crosswise velocity fluctuations within the wake region.

Practical implications

The findings demonstrate the effectiveness of square-lobed trailing edges as passive control techniques, showing significant implications for improving efficiency, performance and safety of the design in aerospace and industrial systems.

Originality/value

This paper demonstrates that the square-lobed trailing edges are effective in reducing the mean reattachment length and pressure fluctuations in transonic conditions. The study evaluates the efficacy of different configurations, deflection angles and lobe widths on flow and provides insights into the flow physics of passive flow control systems.

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: 1 April 1987

S. Hamilton

Increasing power densities within electronic equipment have led to a rise in the number of heat related problems being experienced. This paper describes the use of computerised…

Abstract

Increasing power densities within electronic equipment have led to a rise in the number of heat related problems being experienced. This paper describes the use of computerised thermal analysis techniques to optimise the design of passive thermal management systems for electronic equipment.

Details

Circuit World, vol. 14 no. 1
Type: Research Article
ISSN: 0305-6120

Article
Publication date: 10 April 2023

Ahmad Sukkar, Moohammed Wasim Yahia, Emad Mushtaha, Aref Maksoud, Salem Buhashima Abdalla, Omar Nasif and Omer Melahifci

This study analyzes the effect of the techniques of active teaching and learning as a way of delivery on the outcomes of quality learning. Focusing on the courses of architectural…

Abstract

Purpose

This study analyzes the effect of the techniques of active teaching and learning as a way of delivery on the outcomes of quality learning. Focusing on the courses of architectural science taught in a nontraditional method using various active learning strategies, the study takes the case study of the course Building Illumination and Acoustics (BIA) delivered in the academic year 2019–2020 at the University of Sharjah (UoS)'s Architectural Engineering Department (AED).

Design/methodology/approach

Utilizing both quantitative and qualitative research approaches, the study applied a case study and survey as methods. A questionnaire was designed and performed to assess the level of students' satisfaction with the implemented active teaching method.

Findings

The vibrant learning setting made the students actively engaged and more motivated and enthusiastic. The active learning practices used, including employing senses as in sight and hearing, reasoning rationally and intuitively, reflecting and acting, working steadily and in fits and starts, creating mathematical models, visualizing and memorizing and drawing analogies, were efficient in boosting their ability to comprehend theoretical concepts more effectively. The delivery style effectively enhances quality learning when various active techniques are used pedagogically beyond being merely a utilitarian instrument to prepare novice students of architectural engineering to fulfill practical challenges.

Research limitations/implications

This article focuses specifically on a theoretical, scientific non-studio course in a particular program of architectural engineering in a particular semester before the dramatic changes in styles of teaching delivery that happened due to the COVID-19 pandemic. Future research could further highlight its results by comparing them to statistical evidence of the development of the course, especially for the duration of online teaching during the pandemic and the hybrid teaching period after it.

Originality/value

This article contributes to the development of teaching and learning of architectural engineering in the local Emirati context by putting original theories of teaching into practice. This paper further contributes to the field of architectural pedagogy in terms of the effect of active learning in the architecture field in the non-studio courses in higher education in the United Arab Emirates.

Article
Publication date: 23 November 2010

Richard C.A. Pitwon, Ken Hopkins, Dave Milward, Malcolm Muggeridge, David R. Selviah and Kai Wang

The purpose of this paper is to present the latest results from research and development into future optical printed circuit board (OPCB) interconnects and low‐cost assembly…

Abstract

Purpose

The purpose of this paper is to present the latest results from research and development into future optical printed circuit board (OPCB) interconnects and low‐cost assembly methods.

Design/methodology/approach

A novel method of high‐precision passive alignment and assembly to OPCBs was invented and a full evaluation platform developed to demonstrate the viability of this technique.

Findings

The technique was successfully deployed to passively align and assemble a lens receptacle onto an embedded polymer waveguide array in an electro‐OPCB. The lens receptacle formed a critical part of a dual lens pluggable in‐plane connection interface between peripheral optical devices and an OPCB. A lateral in‐plane mechanical accuracy of ±2 μm has been measured using this technique.

Research limitations/implications

As this is a free space optical coupling process, surface scattering at the exposed waveguide end facet was significant.

Originality/value

This paper details a novel method of passively assembling arbitrary optical devices onto multi‐mode optical waveguides and outlines the procedure and equipment required. A lens coupling solution is also presented which reduces susceptibility of a connecting optical interface to contamination.

Details

Circuit World, vol. 36 no. 4
Type: Research Article
ISSN: 0305-6120

Keywords

Article
Publication date: 1 August 2005

Carl A. Rodrigues

Seeks to examine the impact of national culture on the importance level students place on ten teaching techniques commonly used by US business instructors.

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Abstract

Purpose

Seeks to examine the impact of national culture on the importance level students place on ten teaching techniques commonly used by US business instructors.

Design/methodology/approach

Undergraduate and MBA business students, including students born in the USA and students born in a foreign country, rated the techniques.

Findings

Ratings by students from cultures preferring techniques where the instructor provides high structure differ slightly from the ratings by students from cultures preferring techniques where the instructor provides lower structure.

Research limitations/implications

The respondents are from one US university. Therefore, the results cannot be generalized.

Practical implications

The framework is useful in that it reminds instructors/trainers that, if a group of learners is from the same culture, a customized technique may be effective but, if the group is from diverse cultures, it reminds them that they may have to provide more structure to those students and trainees from cultures which learn best through directive techniques than to those which learn best through less directive techniques.

Originality/value

Some researchers have examined how culture influences learning‐style preference. However, much of the existing literature has been contributed by educational psychologists, whose major concern has been the academic performance of Blacks, Hispanics, and American Indians being lower than that of whites in the USA. This study addresses the impact of national culture on students’ teaching/learning technique preference.

Details

Journal of Management Development, vol. 24 no. 7
Type: Research Article
ISSN: 0262-1711

Keywords

Article
Publication date: 1 January 1992

Maurice B. Line

Demotivation of staff, though well developed in most places, isstill capable of improvement. Rigid grading structures and hierarchiescan help. More direct techniques include…

Abstract

Demotivation of staff, though well developed in most places, is still capable of improvement. Rigid grading structures and hierarchies can help. More direct techniques include ignoring staff, forgetting they belong to the library or who they are, brushing aside suggestions, claiming credit for their ideas, distancing yourself from disasters, showing no interest in staff as people, criticizing but never praising (preferably in front of others), confusing staff, being inconsistent, patronizing staff, giving them unclear job descriptions and reporting lines, avoiding consultation, excluding them from any involvement, and being negative yourself. In spite of a few dangers, these methods infallibly bring results.

Details

Library Management, vol. 13 no. 1
Type: Research Article
ISSN: 0143-5124

Keywords

Article
Publication date: 12 May 2022

Syed Awais Ali Shah, Bingtuan Gao, Ajeet Kumar Bhatia, Chuande Liu and Arshad Rauf

Barge-type offshore floating wind turbine (OFWT) commonly exhibits an under-actuated phenomenon in an offshore environment, which leads to a potential vibration-damping hazard…

Abstract

Purpose

Barge-type offshore floating wind turbine (OFWT) commonly exhibits an under-actuated phenomenon in an offshore environment, which leads to a potential vibration-damping hazard. This article aims to provide a new robust output feedback anti-vibrational control scheme for the novel translational oscillator with rotational actuator (TORA) based five-degrees of freedom (5-DOF) barge-type OFWT in the presence of unwanted disturbances and modeling uncertainties.

Design/methodology/approach

In this paper, an active control technique called TORA has been used to design a 5-DOF barge-type OFWT model, where the mathematical model of the proposed system is derived by using Euler–Lagrange's equations. The robust hierarchical backstepping integral nonsingular terminal sliding mode control (HBINTSMC) with an adaptive gain is used in conjunction with extended order high gain observer (EHGO) to achieve system stabilization in the presence of unwanted disturbances and modeling uncertainties. The numerical simulations based on MATLAB/SIMULINK have been performed to demonstrate the feasibility and effectiveness of the proposed model and control law.

Findings

The numerical simulation results affirm the accuracy and efficiency of the proposed control law for the TORA based OFWT system. The results demonstrate that the proposed control law is robust against unwanted disturbances and uncertainties. The unknown states are accurately estimated by EHGO which enables the controller to exhibit improved stabilization performance.

Originality/value

A new mathematical model of the 5-DOF barge-type OFWT system based on TORA is the major contribution of this research paper. Furthermore, it provides a new adaptive anti-vibration control scheme by incorporating the EHGO for the proposed model.

Article
Publication date: 16 August 2022

Helen Dion, Martin Evans and Peter Farrell

Energy-saving is a growing challenge worldwide because of population growth, economic activity and high consumption rates that are unsustainable in the long term. Health-care…

Abstract

Purpose

Energy-saving is a growing challenge worldwide because of population growth, economic activity and high consumption rates that are unsustainable in the long term. Health-care facilities and hospitals face the challenge of increases in operational costs. This paper aims to appraise challenges to adopting energy-saving policies and proposes a roadmap for sustainability and energy efficiency management in hospitals and health-care facilities.

Design/methodology/approach

Eight hospitals were examined as case studies through qualitative interviews with hospital senior management, executives and health-care facilities managers in addition to collecting relevant data from the literature; there is critical appraisal and content analysis of this data.

Findings

This study established factors influencing implementation and challenges to energy-saving strategies. This study proposed guidelines for efficient energy management in hospitals and health-care facilities. This study concluded that the best performance is secured by integrating the proposed guidelines with the adoption of ISO 50001 energy management systems to achieve the United Nations’ sustainable development goal – SDG 7 “affordable and clean energy”.

Research limitations/implications

This study is limited to the initiatives/experiences of the hospitals studied in the Middle East and North Africa region.

Originality/value

This study’s findings, conclusions, recommendations and proposed guidelines enrich the body of knowledge. This will allow industry key stakeholders, hospitals and health-care facilities managers to overcome challenges of implementing energy management. In addition, adopting the proposed guidelines will improve energy efficiency and help hospitals in green initiatives as they seek to demonstrate their support for United Nations’ sustainable development goals.

Details

Journal of Engineering, Design and Technology , vol. 21 no. 2
Type: Research Article
ISSN: 1726-0531

Keywords

Content available
Book part
Publication date: 24 October 2022

Eugene Beresin

Abstract

Details

Music
Type: Book
ISBN: 978-1-83867-316-1

Article
Publication date: 4 December 2018

Marjan Goodarzi, Saeed Javid, Ali Sajadifar, Mehdi Nojoomizadeh, Seyed Hossein Motaharipour, Quang-Vu Bach and Arash Karimipour

With respect to two new subjects, i.e. nanofluids and microchannels, in heat transfer systems and modern techniques used for building them, this paper aims to study on effect of…

Abstract

Purpose

With respect to two new subjects, i.e. nanofluids and microchannels, in heat transfer systems and modern techniques used for building them, this paper aims to study on effect of using aluminum oxide nanoparticles in non-Newtonian fluid of aqueous solution of carboxy-methyl cellulose in microtube and through application of different slip coefficients to achieve various qualities on surface of microtube.

Design/methodology/approach

Simultaneously, the effect of presence of nanoparticles and phenomenon of slip and temperature jump has been explored in non-Newtonian nanofluid in this essay. The assumption of homogeneity of nanofluid and fixed temperature of wall in microtube has been used in modeling processes.

Findings

The results have been presented as diagrams of velocity, temperature and Nusselt Number and the investigations have indicated that addition of nanoparticles to the base fluid and increase in microtube slip coefficient might improve rate of heat transfer in microtube.

Originality/value

The flow of non-Newtonian nanofluid of aqueous solution of carboxy methyl cellulose-aluminum oxide has been determined in a microtube for the first time.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 29 no. 5
Type: Research Article
ISSN: 0961-5539

Keywords

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