Statistical turbulence theory and turbulence phenomenology

The application of deductive turbulence theory for validity determination of turbulence phenomenology at the level of second-order, single-point moments is considered. Particular emphasis is placed on the phenomenological formula relating the dissipation to the turbulence energy and the Rotta-type formula for the return to isotropy. Methods which deal directly with most or all the scales of motion explicitly are reviewed briefly. The statistical theory of turbulence is presented as an expansion about randomness. Two concepts are involved: (1) a modeling of the turbulence as nearly multipoint Gaussian, and (2) a simultaneous introduction of a generalized eddy viscosity operator

Governance, sport and the city: realising mega sporting events in London.

Mega sports events have become important tools for cities seeking to enhance their global position, undertake regeneration and promote tourism and there is intense competition to win the rights to host events, particularly the Olympics, World Athletics Championships and FIFA World Cup. Using the case of the abandoned Lee Valley National Athletics Centre (LVNAC) project and the loss of the rights to stage the 2005 World Athletics Championships in London as a case study, this thesis sets out. To explore the inter-relationships between governance, sport and the city, with a particular focus on mega sports events. .A qualitative approach was adopted to enable processes to be explored and to tease out linkages between different aspects of governance, levels of governance, sport and governance and the various interested parties. This thesis is multi-disciplinary in its approach, using concepts from a variety of disciplines including social policy, geography, urban studies and politics. It is underpinned by an integrative theoretical framework drawing elements primarily from urban regime theory, theories of policy networks and multi-level governance. This thesis is based on the premise that the key to understanding the failure of the LVNAC project as well as the development of other mega sporting projects lies in understanding the prevailing governance arrangements. A working hypothesis was developed to guide the thesis, which is that the relative failure of the UK to bid for, and stage mega-sports events in the recent past is rooted within aspects of the network style of governance that evolved in London and other UK cities. In order to explore this proposition and to more fully understand the failure of the LVNAC project this thesis compares how other nations and cities (both within the UK and abroad) approach mega sports events and their experiences of staging mega sports events. Drawing on documentary sources and semi-structured interviews with key players involved with the LVNAC project, the 'story' of the Lee Valley National Athletics Centre is told. The analysis of the LVNAC project locates the project within the evolving governance arrangements for London- the re-instatement of city-wide government and election of the Mayor in 2001. Comparison is made with the subsequent successful London bid for the 2012 Olympics. This thesis demonstrates the importance of governance issues throughout the whole mega sports events process and at all levels of governance. In particular this thesis has shown that three elements of governance -leadership, vision and strategy -play a critical role in securing and delivering successful mega sports events. The failure of the LVNAC project was the result of failures on all these fronts whilst the success of the London Olympic bid was largely because these elements were in place. This thesis highlights the critical role played by cities but also the continuing importance of central government in the mega sporting events process. Furthermore, this thesis has demonstrated the value of studying an apparent failure. So often the emphasis within policy and political arenas is on learning from success and consequently failures are often overlooked as a source of positive knowledge

Improved prediction of laminar leading edge separation

Research was conducted to provide a definite criterion for the prediction of the bubble burst on airfoils typical of those used for fighter wings. The approach taken was to correlate existing airfoil bubble burst data using various parameters at the laminar separation point. The method due to Weber was modified to provide a continuous analytic solution for the velocity distribution around the airfoil leading edge. Coupling the modified Weber method with the Stratford laminar separation prediction method leads to a universal chart giving the conditions at separation as a function of stagnation location and leading edge radius. Application of the combined method to available two-dimensional airfoil data resulted in an empirical criterion presenting the limiting local velocity gradient at separation as a function of the boundary layer momentum thickness at separation for bubble burst. The correlation leads as well to the qualitative explanation of two types of laminar stall: thin airfoil and leading edge. The validity of the correlation is demonstrated by predicting the lift coefficient and angle of attack for stall on airfoils with leading edge or trailing edge flaps

Materials processing in space: Early experiments

The characteristics of the space environment were reviewed. Potential applications of space processing are discussed and include metallurgical processing, and processing of semiconductor materials. The behavior of fluid in low gravity is described. The evolution of apparatus for materials processing in space was reviewed

Evaluation of a large capacity heat pump concept for active cooling of hypersonic aircraft structure

Results of engineering analyses assessing the conceptual feasibility of a large capacity heat pump for enhancing active cooling of hypersonic aircraft structure are presented. A unique heat pump arrangement which permits cooling the structure of a Mach 6 transport to aluminum temperatures without the aid of thermal shielding is described. The selected concept is compatible with the use of conventional refrigerants, with Freon R-11 selected as the preferred refrigerant. Condenser temperatures were limited to levels compatible with the use of conventional refrigerants by incorporating a unique multipass condenser design, which extracts mechanical energy from the hydrogen fuel, prior to each subsequent pass through the condenser. Results show that it is technically feasible to use a large capacity heat pump in lieu of external shielding. Additional analyses are required to optimally apply this concept

The Alcohol Concern SMART recovery pilot project: final evaluation report

Evaluation of the Alcohol Concern/SMART Recovery (Self Mangement and Recovery Training) pilot project. The pilot project ran in England from 2008-2010 and was funded by the Department of Health

High resolution electron microscopy study of a high Cu variant of Weldalite (tm) 049 and a high strength Al-Cu-Ag-Mg-Zr alloy

Weldalite (trademark) 049 is an Al-Cu-Li-Ag-Mg alloy that is strengthened in artificially aged tempers primarily by very thin plate-like precipitates lying on the set of (111) matrix planes. This precipitate might be expected to be the T(sub 1) phase, Al2CuLi, which has been observed in Al-Cu-Li alloys. However, in several ways this precipitate is similar to the omega phase which also appears as the set of (111) planes plates and is found in Al-Cu-Ag-Mg alloys. The study was undertaken to identify the set of (111) planes precipitate or precipitates in Weldalite (trademark) 049 in the T8 (stretched and artificially aged) temper, and to determine whether T(sub 1), omega, or some other phase is primarily responsible for the high strength (i.e., 700 MPa tensile strength) in this Al-Cu-Li-Ag-Mg alloy

Time and frequency stability for the Crustal Dynamics Project

Very long base interferometry (VLBI) and laser ranging to artificial satellites and the Moon were used to determined vector baselines between stations with precisions of about one part in 10 to the 8th power. Deformations and strain accumulations in active earthquake regions were determined by making frequent measurements of baselines between many stations in active areas near plate boundaries

Research on boron filaments and boron reinforced composites

Boron filaments for use as reinforcing phase in composite materials for aerospace structure

Compressive behavior of titanium alloy skin-stiffener specimens selectively reinforced with boron-aluminum composite

A method of selectively reinforcing a conventional titanium airframe structure with unidirectional boron-aluminum composite attached by brazing was successfully demonstrated in compression tests of short skin-stiffener specimens. In a comparison with all-titanium specimens, improvements in structural performance recorded for the composite-reinforced specimens exceeded 25 percent on an equivalent-weight basis over the range from room temperature to 700 K (800 F) in terms of both initial buckling and maximum strengths. Performance at room temperature was not affected by prior exposure at 588 K (600 F) for 1000 hours in air or by 400 thermal cycles between 219 K and 588 K (-65 F and 600 F). The experimental results were generally predictable from existing analytical procedures. No evidence of failure was observed in the braze between the boron-aluminum composite and the titanium alloy