A wind tunnel investigation into the effects of roof curvature on the aerodynamic drag experienced by a light goods vehicle

Roof curvature is used to increase ground vehicle camber and enhance rear-body boat-tailing to reduce aerodynamic drag. Little aerodynamic data is published for light goods vehicles (LGVs) which account for a significant proportion of annual UK licensed vehicle miles. This paper details scale wind tunnel measurements at Re = 1.6 × 106 of a generic LGV utilising interchangeable roof panels to investigate the effects of curved roof profile on aerodynamic drag at simulated crosswinds between -6° and 16°. Optimum magnitudes of roof profile depth and axial location are suggested and the limited dataset indicates that increasing roof curvature is effective in reducing drag over a large yaw range, compared to a flat roof profile. This is primarily due to increased base pressure, possibly from enhanced mixing of longitudinal vortices shed from the rear-body upper side edges and increased turbulent mixing in the near-wake due to the increased effective boat-tail angle

Investigation of the aerodynamic characteristics of a lifting body in ground proximity

The use of cambered hull shapes in the next generation of lighter-than-air vehicles to enhance aerodynamic performance, together with optimized take-off manoeuvre profiles, will require a more detailed understanding of ground proximity effects for such aircraft. A series of sub-scale wind tunnel tests at Re = 1.4 x 106 on a 6:1 prolate spheroid are used to identify potential changes in aerodynamic lift, drag and pitching moment coefficients that are likely to be experienced on the vehicle hull in isolation when in close ground proximity. The experimental data is supported by a preliminary assessment of surface pressure changes using a high order panel method (PANAIR) and RANS CFD simulations to assess the flow structure. The effect of ground proximity, most evident when non-dimensional ground clearance (h/c) < 0.3, is to reduce lift coefficient, increase drag coefficient and increase the body pitching moment coefficient

Smart Materials as Intelligent Insulation

In order to provide a robust infrastructure for the transmission and distribution of electrical power, understanding and monitoring equipment ageing and failure is of paramount importance. Commonly, failure is associated with degradation of the dielectric material; therefore the introduction of a smart moiety into the material is a potentially attractive means of continual condition monitoring. It is important that any introduction of smart groups into the dielectric does not have any detrimental effect on the desirable electrical and mechanical properties of the bulk material. Initial work focussed on the introduction of fluorophores into a model dielectric system. Fluorescence is known to be a visible effect even at very low concentrations of active fluorophores and therefore was thought well suited to such an application. It was necessary both to optimise the active fluorophore itself and to determine the most appropriate manner in which to introduce the fluorophores into the insulating system. This presentation will describe the effect of introducing fluorophores into polymeric systems on the dielectric properties of the material and the findings thus far [1]. Alternative smart material systems will also be discussed along with the benefits and limitations of smart materials as electric field sensors

Magnetic forming studies

Investigation of the tensile strength dependability on the characteristic time over which a pressure pulse is applied to a metal workpiece shows that the mechanical properties of these materials are functions of the rate at which the material is undergoing strain. These results and techniques are used in magnetomotive metal forming

Transparent yttrium hydride thin films prepared by reactive sputtering

Metal hydrides have earlier been suggested for utilization in solar cells. With this as a motivation we have prepared thin films of yttrium hydride by reactive magnetron sputter deposition. The resulting films are metallic for low partial pressure of hydrogen during the deposition, and black or yellow-transparent for higher partial pressure of hydrogen. Both metallic and semiconducting transparent YHx films have been prepared directly in-situ without the need of capping layers and post-deposition hydrogenation. Optically the films are similar to what is found for YHx films prepared by other techniques, but the crystal structure of the transparent films differ from the well-known YH3 phase, as they have an fcc lattice instead of hcp

Written medical discharge communication from an acute stroke service: a project to improve content through development of a structured stroke-specific template

Specific guidelines for the content of discharge summaries from acute stroke services do not currently exist. The aims of this project were to assess the strengths and weaknesses of stroke discharge communication from Imperial College Healthcare NHS Trust, to develop a structured template to guide completion, and to re-audit discharge communication following its implementation. The audit compared local performance against record standards from the Academy of Medical Royal Colleges (1), which was augmented by criteria generated from the British Association of Stroke Physicians (BASP) Stroke Service Standards (2). Discharge information was examined within the Trust’s Electronic Discharge Communication (EDC) system to determine the recording of selected items for consecutively discharged patients from the hyperacute and acute stroke units. The audit was repeated following implementation of a newly developed stroke-specific discharge summary template. Fifty-one EDC summaries were examined at baseline (July 2012) and 30 summaries at re-audit (January 2013). The criteria which showed low adherence initially and which showed the most significant improvement following the introduction of the template were the guidance on blood pressure and lipids targets (increased from 2% and 0% respectively at baseline, to 93% post intervention), and the driving and flying advice (from 3% to 79%). Documentation was also seen to improve for measures of physical and cognitive function, discharge arrangements, and follow up plans. This audit cycle has demonstrated improvement in the consistency of content within written discharge communication following the introduction of a structured stroke-specific template adhering to combined criteria from identified standards

Quantum-limited mass flow of liquid 3^{3}He

We consider theoretically the possibility of observing unusual quantum fluid behavior in liquid $^{3}$He and solutions of $^{3}$He in $^{4}$He systems confined to nano-channels. In the case of pure ballistic flow at very low temperature conductance will be quantized in units of $2m^{2}/h$. We show that these steps should be sensitive to increases in temperature. We also use of a random scattering matrix simulation to study flow with diffusive wall scattering. Universal conductance fluctuations analogous to those seen in electron systems should then be observable. Finally we consider the possibility of the cross-over to a one-dimensional system at sufficiently low temperature where the system could form a Luttinger liquid