538 research outputs found
Helical buckling of Skyrme-Faddeev solitons
Solitons in the Skyrme-Faddeev model on R^2xS^1 are shown to undergo buckling
transitions as the circumference of the S^1 is varied. These results support a
recent conjecture that solitons in this field theory are well-described by a
much simpler model of elastic rods.Comment: 24 pages, 9 figure
Helical buckling of Skyrme-Faddeev solitons
Solitons in the Skyrme-Faddeev model on R^2xS^1 are shown to undergo buckling
transitions as the circumference of the S^1 is varied. These results support a
recent conjecture that solitons in this field theory are well-described by a
much simpler model of elastic rods.Comment: 24 pages, 9 figure
Unsteady flow around bluff bodies spanning thin rectangular ducts
This project consists of a two-pronged computational and experimental approach to the
study of flow in closed, thin rectangular ducts with a partial cubic blockage. Results are
presented at three different bulk Reynolds numbers, ReD = 5600, 10400 and 15600, based
on the channel height, which is also the blockage dimension. The new experimental data
produced consists of fluctuating pressure measurements at the cube surface, with 2D-2C
PIV snapshots captured simultaneously in the wake region. In addition to this, DNS
data is produced at the lowest Reynolds number of ReD = 5600, allowing more detailed
comparisons where PIV laser access was not possible. Comparisons are drawn between
the data and URANS CFD simulations. A literature review and preliminary testing process narrowed down the considered URANS models to the two-layer k−ε model and the Elliptic Blending Reynolds Stress Model, or EBRSM. In the light of the new data,
these two URANS models are compared in order to better understand their strengths and
weaknesses. Particular regard is given to the prediction of large-scale unsteady behaviour,
with a focus on vortex shedding. This unsteady phenomenon was found to be present
and to have a significant effect on the flow in the near-cube and wake regions. Results
show that certain aspects of this behaviour are captured with only limited accuracy by
the URANS models tested. As a result, inaccuracies are also found in the mean simulated
velocity fields. The shortcomings appear more pronounced at higher flow rates. At a
given flow rate, they are more severe in regions of the flow where organised unsteadiness
is large relative to the mean values. It is suggested that inaccuracies in mean URANS
predictions are a result of limitations in model capability for unsteady flows, and that
validation cases may be pertinent to address this.Open Acces
Contrasting views of induction
This article focuses on the induction experiences of new academic staff and the role of their head of department in this process. Respondents reflected on personal experiences and their narratives give a fine-grained account of the same event from two contrasting perspectives. We expected to find that the heads would be key figures in the induction process, but we discovered a more complex situation in which contributions were largely hidden or indirect. We encountered many contradictions as each party recalled events. Meaningful communication had been sporadic at best, and professional and personal relationships were left undeveloped. In all cases, there was little genuine understanding of the potential of induction, and this was particularly evident in the lack of personal action displayed by the new academics. Some heads had developed a deeper theoretical position on induction but few of their ideas were realized in practice. We propose that this was mainly due to the heads’ lack of experience and because induction outcomes were not systematically evaluated
Graphicality: why is there not such a word?
The concept of graphicality first appeared in the work of Edgar Allan Poe. Taking its title from Poe’s painterly metaphor, this paper seeks to understand how graphicality may inform aspects of design thinking that have been neglected. We explore the current use, origins and aspects of graphicality, and contextualise it in some real world scenarios to reaffirm how we live in a graphic age, and how graphicality must be better understood in the way we comprehend other displays of human ability, such as musicality. Poe provides us with a starting point for relating the physical and mental domains of image interpretation. Graphicality is shown to work on a continuum between subjectivity and objectivity, not as something to be measured but appreciated in how it enhances understanding and knowledge. This has implications for many academic disciplines, specifically in how it enhances our appreciation of the graphic in graphic design
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