The Nature of Things - A Design Narrative

The subject of this narrative is the creative process. It concerns a young Chinese graduate who has studied in London. On the eve of her graduation ceremony she learns something important about her abilities. It is a vague hint of the way her creative life might develop, but many years must pass before she can practice her skills and express her understanding. The illustrated narrative is written in both English and Chinese

A numerical analysis of buoyancy-driven melting and freezing

A numerical investigation of transient natural convective heat transfer with coupled phase change is presented. The numerical model attempts to capture the solid-fluid interface using a fixed-grid solution and is applied to two pure substance cases found in published literature, one considering the melting of 95% pure Lauric acid and the other involving the freezing of water. The governing equations are solved in a manner such that if the temperature falls below the freezing isotherm then the convection terms in the equations of motion are effectively disengaged. Variations in the specific heat of the material are incorporated in order to account for the phase change. A non-Boussinesq approach is considered which accounts for any density extrema in the flow, particularly for the density inversion found in water. In both of the cases considered the phase change occurs between fixed temperature boundaries and Rayleigh numbers rest well within the laminar flow regime. From the results obtained it is demonstrated that a relatively simple numerical technique can be applied to capture the physics of buoyancy-driven melting and freezing and that the results are in reasonable concurrence with experimental data

A novel method for the provision of flight experience and flight testing for undergraduate aeronautical engineers at the University of Strathclyde

The Department of Mechanical Engineering at the University of Strathclyde has developed a novel flight experience/test course for undergraduate Aeronautical Engineers. In common with similar courses at undergraduate level the course contains practical instruction in how an aircraft is flown, an analysis of its stall characteristics and an assessment of an aircraft's performance and stability. However, uniquely, the Strathclyde course consists of dual instructional flights in two seat gliders. This paper contains a detailed description of the flight experience/test course developed at Strathclyde and its incorporation into the undergraduate curriculum. A critical analysis of its delivery is also presented

An investigation into the aerodynamic characteristics of catenary contact wires in a cross-wind

An experimental analysis of the aerodynamic characteristics of catenary contact wires is presented. The aerodynamic data obtained were used to calculate the Glauert-Den Harthog criterion for one-dimensional galloping. Utilizing this criterion, the susceptibility to galloping instability of a number of contact wire cross-sections was assessed. The analysis showed that a galloping oscillation can only be induced in a cross-wind when the wire is worn and the flow approaches the wire at an angle of between 7 and 14° to the horizontal. This analysis suggested an explanation for the large-scale oscillations experienced by catenary wires on elevated railway tracks in exposed positions, where the close proximity of the embankment to the wire generates large angles of attack in the flow field around the contact wire

Comparison of the computed flow field around a bubble growing at an orifice using PIV techniques

For bubbles growing rapidly at orifices, the inertia of the liquid displacement and the resultant liquid flow field contribute to the production of an inertia force which tends to retard bubble movement. It is therefore the purpose of this paper to report on a study to examine the validity of liquid velocity fields predicted by potential flow methods and measurements made using Particle Image Velocimetry (PIV) techniques. Air bubbles are generated in water at atmospheric conditions from a 1 mm diameter orifice. The process is transient and occurs over a period of approximately 80 msecs. Therefore a combination of high speed video techniques and PIV image processing has been used to determine the liquid velocity vector fields during the bubble growth, detachment and translation periods. This paper will present a summary of the experimental techniques and the theoretical model and discuss the results of the study

User Defined Function: lidar_3D : NORSEWInD Report UoSNW006

This report describes the User Defined Function Lidar_3D used to interrogate FLUENT data files to provide the relevant data for the MathCAD LiDAR simulation program. The UDF was written in the C programming language and compiled using Microsoft visual studio 2008. This report contains a listing of the program (version 1.03). This report contains a description of the methodology required to compile the UDF so that it may be called by an "execute on demand" call from FLUENT. The report also includes a description of the input and output data file formats

Computational and Experimental Study on the effect of flow field distortion on the accuracy of the measurements made by anemometers on the Fino3 Meteorological mast

This paper reports on the experimental and computational modelling of the flow field around the FINO3 mast and provides an estimate of the amount of distortion that might be expected on instrumentation mounted on such a large structure. The open source C++ toolbox OpenFOAM was used for the CFD analysis. In order to validate the CFD model, experimental work was carried out in an open section wind tunnel using hot wire anemometry to measure the velocity profile around a sub-scale model of part of the FINO3 mast. The experimental data are in good agreement with the data from the CFD simulatio

Feasibility Study of using a LiDAR in the complex flowfield of an offshore platform, to measure wind shear profile.

Offshore wind is the major growth area in the wind industry sector today. However, there remains a key, fundamental missing element - a thorough understanding of the offshore wind climatology and likely wind resource. In 2008 the EU FP7 funded project NORSEWInD was created with a remit to deliver offshore wind speed data at a nominal project hub height acquired in offshore locations in the North, Baltic and Irish seas. Part of the overall NORSEWInD project was the use of LiDAR remote sensing (RS) systems mounted on offshore platforms to measure wind velocity profiles at a number of locations offshore. The data acquired from the offshore RS measurements was fed into a large and novel wind speed dataset suitable for use by the wind industry. The data was also fed into key areas such as forecasting and MESOSCALE modelling improvements. One significant problem identified was the effect of platform interference effects on the RS data. Therefore, part of the fundamental research incorporated into the NORSEWInD project was an investigation into the possible extent and effect of the interference on the measured data from the various mounting platforms. This paper reports on the Computational Fluid Dynamics (CFD) modelling of the wind flows over the platforms and the verification of the CFD models by the use of sub scale wind tunnel models employing three dimensional Constant Temperature Anemometers (CTAs) to measure local velocity vector data

Study of a regenerative pump using numerical and experimental techniques

Regenerative pumps are the subject of increased interest in industry as these pumps are low cost, low specific speed, compact and able to deliver high heads with stable performance characteristics. The complex flow-field within the pump represents a considerable challenge to detailed mathematical modelling as there is significant flow separation in the impeller blading. This paper presents the use of a commercial CFD code to simulate the flow within the regenerative pump and compare the CFD results with new experimental data. The CFD results demonstrate that it is possible to represent the helical flowfield for the pump which has only been witnessed in experimental flow visualisation until now. The CFD performance results also demonstrate reasonable agreement with the experimental tests. The CFD models are currently being used to optimise key geometric features to increase pump efficiency