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.
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Research not only plays an important part in many of the activities which influence our day‐to‐day life, but it can readily be seen to do so. Why then, it might be asked, do…
Abstract
Research not only plays an important part in many of the activities which influence our day‐to‐day life, but it can readily be seen to do so. Why then, it might be asked, do teachers and administrators tend to regard educational research as something that bears little or no relation to the problems which they face? Three years ago, the Society for Research into Higher Education was set up to make research findings more widely available and to promote their more effective use. In this article, Dr Oxtoby reports on the Society's Third Annual Conference and gives his own views on the need to look more closely at the relationship between research and educational practice.
Despite the growing emphasis on revitalizing the technical and vocational education and training (TVET) sector in Bangladesh, very little discussion has taken place on reforming…
Abstract
Purpose
Despite the growing emphasis on revitalizing the technical and vocational education and training (TVET) sector in Bangladesh, very little discussion has taken place on reforming the current inflexible transition pathways, from TVET to the universities. This paper aims to reflect critically on the existing literature on TVET, in the global and national context, and the experiences of students and TVET experts, to develop a model of collaboration between the polytechnic institutes and the universities in Bangladesh.
Design/methodology/approach
This paper follows a qualitative strategy of enquiry, using a mix of critical reflection on literature on TVET and higher education and unstructured interviews with two TVET experts, four TVET students and four students from a public university. It draws on the theories of collaboration and uses exemplary cases to illustrate and support the line of reasoning.
Findings
This paper identifies that there is resource dependency between the polytechnic institutes and universities in Bangladesh, and their institutional environment necessitates them to form collaboration to ensure flexible transition pathway, from polytechnic institutes to universities; this paper proposes a model for such collaboration.
Practical implications
This paper offers a guideline for forming collaboration among the relevant stakeholders.
Social implications
Collaboration between polytechnic institutes and universities in Bangladesh is likely to address the inequitable nature of TVET, by improving its social status and acceptance, as well as allowing higher income opportunity and greater mobility for the TVET graduates, coming especially from humble socio-economic backgrounds.
Originality/value
This paper contributes in the recent discussions on how collaboration among different stakeholders can contribute in achieving the sustainable development goals, with special emphasis on TVET.
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Many engineering staff in the Health Service, from craftsmen to professional engineers, enter from outside the service at varying stages in their careers and from a variety of…
Abstract
Many engineering staff in the Health Service, from craftsmen to professional engineers, enter from outside the service at varying stages in their careers and from a variety of previous employments. Whilst more is now being done in the way of basic training via a substantial craft apprenticeship scheme and an honours degree studentship scheme, it is likely that substantial outside recruitment will continue for the foreseeable future. The Health Service is not primarily an engineering organisation, engineering staff total only 10 000 out of a total of 800 000 employees and the main training effort is of course in the medical, para medical, and nursing fields. Thus the engineering side of the Health Service contains numbers of staff trained in their basic trade or profession, but lacking knowledge of areas specialised to the Health Service. Because of their diversity of backgrounds and the breadth of knowledge required in the Health Service there are also gaps in more basic knowledge. Also, given the pace of change in some technologies, updating is necessary for all staff.
Hiram Ting, Wee Ming Lau, Jun-Hwa Cheah, Yusman Yacob, Mumtaz Ali Memon and Evan Lau
The purpose of this paper is to examine the effect of perceived quality on intention to revisit coffee concept shops among regular and irregular consumers. Specifically, the…
Abstract
Purpose
The purpose of this paper is to examine the effect of perceived quality on intention to revisit coffee concept shops among regular and irregular consumers. Specifically, the framework developed by Pine and Gilmore (2000) is adopted to look into the effect of product, service and experience qualities on intention to revisit.
Design/methodology/approach
The explanatory sequential mixed-methods design was used to articulate the intention of consumers to revisit coffee concept shops. A preliminary study was conducted to define regular and irregular consumers. Self-administered questionnaire was first administered before using interview to elicit more insights and triangulate the findings.
Findings
The combination of both quantitative and qualitative findings show that the experiences of regular consumers at coffee concept shops include personal routine activities, while the experiences of irregular customers are composed of occasions with specific and collective purposes. While the intention to revisit of the former is related to the product and service quality, the intention of the latter is largely affected by its service and experience quality.
Originality/value
Given the rapid rise of coffee concept shops in the developing markets, the use of a mixed-methods design provides more insights into the intention to revisit of the regular and irregular consumers. It underscores the importance for the organisations to know what really matters to the diverse consumers.
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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 tension…
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.