Improved two-equation k-omega turbulence models for aerodynamic flows

Two new versions of the k-omega two-equation turbulence model will be presented. The new Baseline (BSL) model is designed to give results similar to those of the original k-omega model of Wilcox, but without its strong dependency on arbitrary freestream values. The BSL model is identical to the Wilcox model in the inner 50 percent of the boundary-layer but changes gradually to the high Reynolds number Jones-Launder k-epsilon model (in a k-omega formulation) towards the boundary-layer edge. The new model is also virtually identical to the Jones-Lauder model for free shear layers. The second version of the model is called Shear-Stress Transport (SST) model. It is based on the BSL model, but has the additional ability to account for the transport of the principal shear stress in adverse pressure gradient boundary-layers. The model is based on Bradshaw's assumption that the principal shear stress is proportional to the turbulent kinetic energy, which is introduced into the definition of the eddy-viscosity. Both models are tested for a large number of different flowfields. The results of the BSL model are similar to those of the original k-omega model, but without the undesirable freestream dependency. The predictions of the SST model are also independent of the freestream values and show excellent agreement with experimental data for adverse pressure gradient boundary-layer flows

Assessment of higher order turbulence models for complex two- and three-dimensional flowfields

A numerical method is presented to solve the three-dimensional Navier-Stokes equations in combination with a full Reynolds-stress turbulence model. Computations will be shown for three complex flowfields. The results of the Reynolds-stress model will be compared with those predicted by two different versions of the k-omega model. It will be shown that an improved version of the k-omega model gives as accurate results as the Reynolds-stress model

From Interesting Times to Critical Times? Teacher Education and Educational Research in England

Vol. 3. No. 1 APR 2013 Before moving to Oxford, Ian Menter was Professor of Teacher Education at the University of Glasgow. Prior to that he held posts at the University of the West of Scotland (Dean of Education and Media), London Metropolitan University (Head of School of Education), University of the West of England and the University of Gloucestershire. Ian was President of the Scottish Educational Research Association from 2005 to 2007 and chaired the Research and Development Committee of the Universities' Council for the Education of Teachers from 2008 to 2011. Ian is an Academician of the Academy of Social Sciences and a Fellow of the Royal Society of Arts and is a Visiting Professor at the University of Nottingham and at Newman University College, Birmingham. He is a convenor of two UK-wide research groups, TEG (Teacher Education Group) and CAPeR-UK (Curricululum, Assessment and Pedagogy Reform across the UK). In this article Ian critically reflects on the future of educational research in light of current policy developments related to teacher education in England

Hypersonic flows as related to the National Aerospace plane

Experimental data for a series of 2-D and 3-D shock wave/boundary layer interaction flows at Mach 8.2 are presented. The test bodies, composed of simple geometric shapes fastened to a flat plate test bed, were designed to generate flows with varying degrees of pressure gradient, boundary layer separation, and turning angle. The data include surface pressure and heat transfer distributions as well as limited mean flowfield surveys both in the undisturbed and interaction regimes. The data are presented in a convenient form to be used to validate existing or future computational models of these hypersonic flows

Entrepreneurial ecosystems: a dynamic lifecycle model

The concept of entrepreneurial ecosystems has been used as a framework to explain entrepreneurial activities within regions and industrial sectors. Despite the usefulness of this approach, the concept is under-theorized, especially with regard to the evolution of entrepreneurial ecosystems. The current literature is lacking a theoretical foundation that addresses the development and change of entrepreneurial ecosystems over time and does not consider the inherent dynamics of entrepreneurial ecosystems that lead to their birth, growth, maturity, decline, and re-emergence. Taking an industry lifecycle perspective, this paper addresses this research gap by elaborating a dynamic entrepreneurial ecosystem lifecycle model. We propose that an ecosystem transitions from an entrepreneurial ecosystem, with a focus on new firm creation, towards a business ecosystem, with a core focus on the internal commercialization of knowledge, i.e., intrapreneurial activities, and vice versa. Our dynamic model thus captures the oscillation that occurs among entrepreneurs and intrapreneurs through the different phases of an ecosystem’s lifecycle. Our dynamic lifecycle model may thus serve as a starting point for future empirical studies focusing on ecosystems and provide the basis for a further understanding of the interrelatedness between and co-existence of new and incumbent firms

Review of Bristol Musicians’ Co-Operative

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STS - Legal Connotations

Fragile man, tailored to his planet Earth, having demonstrated in Apollo missions that he can overcome hazards of travel to the moon and return, and in Skylab and Soyuz missions that he can live in the weightlessness of space for an appreciable period of time during which he can maintain an experimental space laboratory, is about to embark in the Space Shuttle on ventures that will truly comprise another giant step for mankind

Commercial Space Activities Under the Moon Treaty

This paper examines the apprehension of private enterprise to invest funds in a moon activity requiring sharing of profits with States that had not shared in the risks involved. In light of the Treaty\u27s negotiated history, conclusions made are that the nature of the sharing has not yet been determined; that such must await a subsequent separate treaty negotiation for the governing international regime when exploitation is about to become feasible, an eventuality perhaps thirty or more years from now; that in the interim, there is no moratorium on exploitation and States may authorize their governmental and nongovernmental entities to undertake exploitation of the moon\u27s resources