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This thesis aims to identify how British army bands in the interwar years were a primary stakeholder in the music industry and to explore their role in projecting soft power for the British military. There were approximately 7,000 full-time bandsmen serving in the British army, which was about a third of the total number of musicians in the music profession in the United Kingdom. The War Office was the largest employer of professional musicians in the country and yet there has been very little acknowledgement of the contribution made by this body of musicians, both to the music industry and to the effectiveness of army operations. This thesis uses models from the business and management literature to interrogate the position of British army music within the context of military structures and the music industry in the interwar years. It reveals the extent that residential insitutions were organised to provide young boys for recruitment into the army as bandsmen and how these boys became an integral part of the music industry. It explores how army music set the standard for training and performance while creating sustainability for the music industry, which relied upon the existence of army bands for its business. The thesis then exposes the tempestuous relationship army bands had with the BBC and recording industry, as well as the function the military played in the adoption of an international standard of musical pitch. Finally, it uncovers the effective role and soft power influence of British army bands and their music in the maintenance of British imperial authority, at home and overseas, and the tragic consequences of operating at the forefront of the military campaign in Ireland.

This thesis investigates cross curricular models (integrated curricula) and explores claims by advocates of such models that they enhance learning. A Case Study describes a primary school’s journey in developing its curriculum and pedagogy and highlights the questions that were asked and which relate to the theoretical accounts of knowledge and integrating curricula outlined in the study. It traces the origins of cross curricular studies to Dewey and the pragmatist view of knowledge and in the UK to the Plowden Report (1967). Exploring some cross curricular models, it indicates that they may do little to enhance learning as links between subjects can be spurious with the focus often on developing skills rather than knowledge, skills and understanding due to the constructivist origins on which these models have been based. Links between curriculum and pedagogy are investigated and it is suggested that developing a deeper understanding of knowledge and its concepts demands a more active approach to learning. Questioning the absence of any theory of knowledge by many modern curriculum designers, it also explores the social realist approach to knowledge which justifies bringing knowledge back into the school curriculum. It claims that the complex connections between subjects at a conceptual level make integration possible and will demand a more active learning process resulting in a deeper understanding of knowledge. Skills are developed through the logical demands and modes of enquiry of the school subjects and not through skills based models in which they are taught context free. A comparison is made between a cross curricular topic through a traditional approach and an approach through a conceptual lens which involves a deeper study of the individual subjects, brings a sharper focus to the study and allows generalisations to be made.

This thesis aims to develop the foundations for a new validation strategy for route-based road weather forecasts that will enable validation of route-based models at a vastly improved spatial and temporal resolution, and in doing so provide a tool for rapid appraisal of new model parameterisations. A validation strategy that uses clustering techniques to create clusters of forecast points with similar geographical and infrastructure characteristics is presented, as well as two methodologies for de-parameterising key geographical and infrastructure parameters in the ENTICE route-based model that are currently not measured at the spatial scale demanded by a route-based forecast. The proposed validation strategy facilitates the analysis of forecast statistics at the cluster level, which is shown to provide a more representative measure of the model’s spatial forecasting ability. The majority of thermal variations around the study route are well represented by the clustering solutions, presenting the opportunity for new sampling strategies with the potential to validate forecasts at a vastly improved spatial and temporal resolution. De-parameterisation of the road construction and surface roughness parameters within the ENTICE model using Ground Penetrating Radar and airborne LIDAR data has been shown to significantly improve the spatial forecasting ability of ENTICE, with the model changes leading to refinement of the clustering solution which enables it to better capture the physical relationship between road surface temperature and the geographical and infrastructure parameters around the study route. Suggestions for future research are provided along with a blueprint for the future of route-based road weather forecasts.

I. Process: In this essay, the first chapter deals with my concentration on process in music composition, which holds as much importance to my practice as a composer as does the attention given to finished pieces. I include formative experiences with the music of Claude Debussy, Béla Bartók, John Cage and Franco Donatoni. In the second chapter, I explore my own process of composing by looking into each of the ten individual pieces from my PhD Portfolio of Compositions. II. Portfolio of Compositions: 1. Elegy for Fir Tree for eight strings (2004) 2. Coyote Nocturne for flute, violin and piano (2006) 3. The Indian Fort Theatre for string quartet (2006) 4. Three Moths for flute, piano and bass clarinet (2006) 5. Catalyst of Filament for celesta, harp and harmonium (2006) 6. Twister Season for vibraphone, marimba, two pianos, cello and double bass (2006) 7. Six Journeys for bass clarinet and piano (2006/2007) 8. horrifictionalexander graham belladonna for flute, guitar and bass clarinet (2007) 9. Stalking the Unseeable Animal for flute, clarinet, piano and string quartet (2007) 10. The Lightning Bug Hour for flute, vibraphone and piano (2008)

Cytogenetic analysis was performed on 40 non-Hodgkin's lymphoma (NHQ node biopsies. Chromosomes X, 3 and 12 were the most frequently gained; of the much rarer monosomies, loss of chromosome 13 was most common. Structural abnormalities primarily involved chromosomes 14,1,18,6 and 17. A markedly greater number of chromosome gains were associated with low-grade disease when compared to high-grade. In order to obtain further information from the cytogenetic analysis of the NHL karyotypes, the fluorescence in-situ hybridisation (FISH) technique was applied to the series. The activation state of additional X-chromosomes was examined and evidence that more than one X-chromosome was present in the active state in 4/9 cases was obtained. Further, in an apparent case of monosomy X, a marker was identified as an abnormal X-chromosome by chromosome painting. Interphase FISH was applied to NHL cells and numerical chromosome changes were identified; this approach was also attempted on aged bone marrow smears from acute lymphocytic leukaemia patients, in order to test the utility of the technique on archival material. Dual chromosome painting was used to elucidate the origins of add(14) chromosomes in 8 of the cases. In the control and two other cases the translocated material was demonstrated to be from chromosome 18, in two cases it was from chromosome 3 and in one case them was an insertion of chromosome 11 material. it was not possible to identify the origins of the translocated material in one NHL and in the final case the apparent add(14) was demonstrated not to contain chromosome 14 material. Structural abnormalities of chromosome 6 were investigated both by chromosome painting and by hybridisation of the MYB gene. The latter, which was initially mapped to 6q23 before hybridisation to NHL cells revealed previously unsuspected rearrangements. One case contained extrachromosomal chromatin bodies that appeared to be double minute chromosomes (dmin), which FISH analysis demonstrated to be derived from the X-chromosome and contain centromere-associated DNA. The significance of these results is discussed with reference to previously published series of NHL karyotypes.

The pathway of anaerobic glycolysis of Trypanosoma brucei has been studied by the following five approaches : 1. Ensyme activity required for the various different postulated schemes for anaerobic glycolysis (hexose monophosphate aldolase, glycerol dehydrogenase, glycerophosphate : glucose or glycerophosphate : fructosesphosphate or glycerophosphate : triose or* glycerophosphate : ALP transphosphorylases) have been examined in a variety of assay conditions. Only significant activities of glycerophosphate : ALP transphosphorylase were detectable. 2. Broken cell incubation studies established that there were no significant differences in the sequence of the increase and decrease in glycolytic intermediates between aerobic and anaerobic pathways.3. Whole cell adenylate charge and glycolytic intermediates were assayed in steady-state aerobic, anaerobic and in the transitions between aerobic to anaerobic, and anaerobic to aerobic showed glucose-6-phosj)hate production to be the rate limiting step in anaerobic glucose utilization. Salicylhyaroxamic acid (0.5 mM) inhibited only glycerophosphate oxidase -and so simulated anaerobiosis. 4. The inhibitory effect of glycerol on whole cells metabolising glucose anaerobically showed it to be dependent upon the intracellular concentration of glycerophosphate. Consequently its inhibitory effect is not caused through the inhibition of glucose transport. 5. The concentration of glycerophosphate in cells metabolising glucose under glycerophosphate oxidase inhibited conditions was found to increase rapidly to a concentration that was independent of time and extracellular glycerol concentration. Furthermore it was found to be an intermediate in anaerobic glucose utilization. The results of this work were consistent with the pathway of carbohydrate metabolism under glycerophosphate oxidase inhibition which involved the production of glycerol plus ATP from ADP plus glycerophosphate catalysed by glycerokinase.

This dissertation explores the paradigm of “industrial society” in French and sociology in the middle decades of the twentieth century. It argues that the term “industrial society” was not a concept, but a series of hypotheses and debates connected to the rise of sociology as a form of public intellectualism and the remaking of European social-democratic thought in the shadow of American hegemony and the Cold War. It shows that while sociologists attributed the concept of “industrial society” to nineteenth-century precursors like Saint-Simon, Comte, and Marx, it was in fact a thoroughly twentieth-century reworking of the sociological tradition and social-democratic social theory. “Industrial society” was the way that sociologists transposed their radical commitments into social science, embracing a supposedly “realist,” anti-ideological analysis of the social world as the best intellectual path for a modernized reformism that could either embrace the Cold War status quo or push it toward new forms of radicalism. As a conceptual history, the dissertation explores the industrial-society paradigm in four component parts. These included, first, the “logic of industrialization”: debates about nature and future of social development across capitalist and Communist societies, where sociologists often saw family resemblances rather ideologically opposed systems, and replaced a Marxist teleology of class struggle with more ambiguous evolutionary schemas centered on culture, institutions, and technology. Second, the “managerial revolution,” or the expansion since the early twentieth century, of white-collar social strata and the growing importance of bureaucracy and scientific expertise in most domains of society, especially industry and public administration. Third, the “integration of social conflict,” or the idea that the so-called “industrial society” emerging after World War II would or should be able to manage its conflicts—especially labor conflict—by containing them within a set of rules, institutions, and social contracts that advanced social justice but prevented them from threatening the social order itself. Fourth and finally, the “end of ideology,” which suggested that the result of these other social developments would be a society in which passions cooled, grand ideological visions faded, and politics shifted toward expert management. Stated this way the industrial-society paradigm can appear as merely the sociological expression of a centrist and technocratic postwar consensus. The sociological story told here suggests, however, that it was a major modulation of left-wing social thought in Western Europe and the United States in the middle of the twentieth century. This dissertation follows a cast of characters as they transposed the radical commitments of the 1930s into social science in the 1940s and 1950s, gradually embracing modernist ideals of value-neutral science and pragmatic social reform. In particular, it shows how the sociology they built remade the political left, providing an alternative public sphere and social vision that helped unite the fractious anti- and post-Communist left in countries like France. Beginning in the 1950s, sociology gradually crept into the public consciousness, filling newspapers and popular magazines, left intellectual journals, think-tanks for technocrats, and state-funded research institutes. The overlapping positions of sociologists in the university, the media, and politics enabled them to evangelize a vision of industrial society to people of influence and even in popular culture. By hovering in an ambiguous space between a moderate reformism and radical social thought, between technocrats and militants, industrial-society sociologists created a distinctive form of twentieth-century social-democratic thought that optimistically saw an automated, socialized, and at least partially planned society emerging, almost of its own accord, from the structural forces driving modern social evolution themselves. Temporally, this vision originated in the 1930s in left critiques of the Soviet Union and Stalinism, crystallized in the mid-1950s, and began to fracture amid the social upheaval of the late 1960s. It would be severely shaken by the social conflict and crisis of the 1970s, but in highly ambivalent ways that often led to industrial-society ideas being transmuted into new forms and mobilized by new social actors. The 1968 generation appeared to mount a critique of the industrial-society paradigm and of its sociological advocates, but they often did so by radicalizing its core notions and, and recovering the romantic and utopian impulses that had gradually disappeared from older sociologists’ thinking. While on balance this dissertation tells a story of the acclimation of French and European social science to American norms, the 1970s fracture of the industrial-society paradigm had effects in France that contrasted with the Anglo-American world, most notably the success of new sociological ideas in politics. Unlike in the United States and United Kingdom, which entered the 1980s under aggressive neoliberal leaders, the French Parti Socialiste won the presidency in 1981 with a brand of modernized socialism that borrowed heavily—at least in the party’s rhetoric—from the radicalized industrial-society vision of the 1970s, precisely the sort of ideological rebranding for the left that sociologists had envisioned decades earlier.

The rise of the Environmentalism in every sector of the Industry has lead the aircraft and engine manufacturing companies to develop new generations of more environmentally friendly engines. The companies, encouraged to this purpose, are in a constant research for new manufacturing and production techniques, in order to improve their products, from the environmental point of view, by gaining efficiency in the manufacturing techniques and reduce the fuel consumption and emissions in-flight. Having in mind this scenario, the sponsor of this Project is interested in understanding how changing the materials of the blades, titanium alloys currently, for other lighter materials, such as composites, is going to have an effect in the overall gas turbine efficiency. In the particular case of this Project, it will be studied the influence of the Stiffness and coating Thickness of those non-metallic materials suitable to be employed as coatings on gas turbine fan blades, from the icing point of view. The work procedure will be based on a study of Linear Elastic Fracture Mechanics of bi-material junctions and will extrapolate the general problem to the ice-coatings case, by getting experimental data from tests carried out in an Icing Tunnel. It will be observed that the coating Stiffness has an influence on the Adhesion Level of ice to less stiff materials, if compared with the Adhesion Level of ice to metals. Besides, it will be described how a 0.5 millimetres thin polymeric coating placed over a metallic substrate is enough to reduce the Adhesion Level of ice, hiding any effect that the underneath materials might have on the Adhesion Level.

Icing in an engine breather system can block the engine breather pipe, cause excessive crankcase pressure and degrade the engine performance. In this project, a numerical study, experimental tests and CFD analysis are employed in order to understand condensation and the extent of freezing inside a vertical pipe, a horizontal pipe and a T-joint pipe which are exposed to an external convective cooling. The pipe internal flow is assumed to be a vapour/air mixture. This study has led an evaluation of freezing in an engine breather pipe. The finding in this project highlighted the effects of the pipe internal flow condition (vapour mass fraction, relative humidity, mixture gas flow rate, and inlet relative humidity), the pipe external cooling condition (temperature and air velocity) and pipe thermal conductivity on condensation and extents of ice formation in the pipe. In the experimental study, a test rig has been designed and the condensation and freezing in the pipe have been tested at the Cranfield Icing Tunnel. The local pipe temperatures are measured to validate the numerical and the CFD analysis. The numerical study has led to develop a one dimensional code which used heat and mass analogy to model condensation and freezing in a vertical pipe exposed to a cold air flow (-20C). This code satisfactory predicts the trend and magnitude of the local temperatures and heat transfer coefficient along the vertical pipe at available test condition within an acceptable uncertainty of 25%. This study proposes an empirical correlation based on a degradation factor to evaluate heat transfer coefficient inside a vertical pipe. Its results fit with the experimental data within 15% uncertainty. The CFD methodology developed in this study is capable of predicting condensation rates, local temperatures, heat transfer coefficients and extent of freezing in the pipes with good agreement with the experimental results. The CFD model over predicts the breather pipe ice blockage time due to disparities between an actual engine operating condition and the CFD model. Therefore, an adjustment factor of 1.7 is proposed in this study to correlate the predicted blockage time. The results of this study can help Jaguar to establish guideline for future design of engines breather pipes.

Flying in icing conditions is a real hazard for aircraft as they can undergo potential disastrous increase in drag, reduction in maximum lift which lead to an increase in fuel consumption. Additionally pitot tubes and other sensors can become blocked or their operation compromised. Ice shed from other parts of the aircraft can enter the engine and lead to blade damage. Whilst ice protection systems are comonly used on propellers, the potential benefit of applying them to a fan have not, as yet, been considered suffi cient to o set the cost and energy penalties of such system. As engines become larger, it is more diffi cult to contain ice and self-shedding becomes an increasing hazard for the nacelle and other parts downstream of the fan. The main objectives of the project were to determine the mechanical proper- ties of ice such as might form on an engine fan, in order to help Rolls-Royce in building a finite elements model able to simulate ice shedding from fan blades. Lots were written about ice however only little information about the mechanical properties of impact ice was available in the literature and the values which were, were generally not applicable in the case of aeroengine in icing conditions. According to the literature and from Rolls-Royce photos and films of ice shedding from fan blades, self-shedding mechanisms were ruled by adhesive shear strength and tensile strength. Therefore, the experimental part of the project consisted of measuring these two mechanical properties as well as the density, the sti ness and the grain size of ice grown on titanium substrate. Two test rigs were used to measure the mechanical properties: the \mode I" and the \shear" test rig. The mode I test rig was already available and was only modified in order to test more specimens during each run. This test al- lowed to measure the pressure needed to remove the ice from the substrate in a running icing tunnel. Using equations from the literature, fracture energy, fracture toughness and tensile strength were calculated. The influence of ambient total temperature, cloud liquid water content and tunnel wind speed were investigated. Tensile strength was found to be increasing as the total temperature is decreasing, decreasing as the LWC is increasing and going trough a maximum as the tunnel wind speed is increasing. Values obtained lied in the range from 0.6 to 1.5 J.m-2 (corresponding to between 2 and 10 MPa) which is, in general, higher than the ones reported by other authors. This difference can be explained by the fact that the mode I test was conducted in a running icing tunnel while the previous authors have conducted the mechanical test after the tunnel has been stopped. In parallel, finite element models have been developed and results similar to the experiments were obtained.

Modelling the ice accretion in glaze regime for the supercooled large droplets is one of the most challenging problems in the aircraft icing field. The difficulties are related to the presence of the liquid water film on the surface in the glaze regime and also the phenomena associated with SLD conditions, specifically the splashing and re-impingement. The steady improvement of simulation methods and the increasing demand for highly optimised aircraft performance, make it worthwhile to try to get beyond the current level of modelling accuracy. A semi-empirical method has been presented to characterize the thin water film in the icing problem based on both analytical and experimental approaches. The experiments have been performed at the Cranfield icing facilities. Imaging techniques have been used to observe and measure the features of the thin water film in the different conditions. A series of numerical simulations based on an inviscid VOF model have been performed to characterize the splashing process for different water film to droplet size ratios and impact angles. Based on these numerical simulations and the proposed methods to estimate the thin water film thickness, a framework has been presented to model the effects of the splashing in the icing simulation. These effects are the lost mass from the water film due to the splashing and the re-impingement of the ejected droplets. Finally, a new framework to study the solidification process of the thin water film has been explored. This framework is based on the lattice Boltzmann method and the preliminary results showed the capabilities of the method to model the dynamics, thermodynamics and the solidification of the thin water film.

The usage of polymeric matrix composites in aerospace applications has been significantly prevalent based on their desired material characteristics, which include higher strength, lower weight and heat resistance. With current advancements in nanotechnology, carbon nanotube reinforced polymeric matrix composites may enhance the operational usage of these advanced materials even further. In this study, a set of novel aerospace material candidates are characterized based on their mechanical properties, resilience to liquid erosion, wettability and ice adhesion. The experimental evaluations presented, allow for a preliminary ranking of the polymeric matrix composites and assessment of the influence of reinforcing carbon nanotubes. The role of erosion in particular is highlighted from both a historical viewpoint and based on empirical results for static and dynamic wettability and ice adhesion. Discussion of different ranking systems and fractography arising as a consequence of liquid impact are further addressed in this study. It is found that the candidate samples exhibit different physical parameters but nominally similar erosion resilience despite the presence of the reinforcing carbon nanotubes. The wettability of the experimental materials and their ice adhesion characteristics are further shown to be influenced by the presence of carbon nanotubes and largely dependent upon degradation of the material surfaces.

The runback ice phenomenon is well-known for anti-icing or de-icing systems when the system is not evaporating 100% of the water impinging the surface. The water runs back to the point where the added heat no longer raises the surface temperature above freezing. The water freezes behind this limit. No runback ice is tolerated for some flight configurations, but not for all. Then for o.-design cases, some runback ice may grow on the wings surface. However, data from full-scale realistic runback ice is not very well-known by aircraft manufacturers and they are not sure what thickness is allowed before the e.ect of the ice on the flow becomes too adverse. To better understand full-scale high-fidelity runback ice growth and how it can be simulated with simplistic shapes, test campaigns and CFD studies were undertaken. First of all, tests in the Cranfield icing tunnel were performed. In this work, full-scale runback ice shapes were grown on a model with a full-scale leading edge equiped with an electrical heating system. An innovative moulding and casting technique has been introduced which allowed the production of 3D planarised full-scale realistic runback ice castings. In parallel to the icing tunnel tests, a mass and energy balance has been computed on Excel. This energy and mass balance can predict the heat and mass fluxes involved in the runback ice accretion mechanism. Following this, aerodynamic tests of the ice castings were lead in one of the low speed wind tunnels at Cranfield University. The aerodynamics of simplistic shapes such as geometrical shapes or ballotini layers were also studied. The e.ects of the ice castings on the flow were compared to the e.ects of the simplistic shapes. The tests were done on a flat surface and not on an airfoil due to technical complications. The boundary layer displacement thickness was the parameter used to quantify the e.ect of the shapes on the flow. 2D CFD simulations were performed as a support to the testing but as well to compare with the experimental data. The CFD simulations were for steady or unsteady flow. It has been possible to grow full-scale ice shapes in a relatively small icing tunnel. The shapes have been successfuly moulded and cast using silicone and plaster mixed with polymer. A catalogue of runback ice shapes for different liquid water content, heat inputs and positions along the chord has been recorded. Following the wind tunnel tests, it has been possible to find a relationship between the real ice and the simplistic shapes. Thin runback ice shapes (4 mm) has a similar e.ect on the flow as a layer of 1 mm ballotini. It was found that thicker ice shapes, of the order of 1 cm, is equivalent to a rectangle with rounded corner, associated with 1mm ballotini. The triangle shape which is usually used to simulate runback ice by the aircraft manufacturers, was found to be the most aerodynamically penalising simplisitc shape that has been investigated in this PhD project. It was found that rounded corners greatly improve the representativeness of the simplistic shapes, such as triangle or rectangle.

This dissertation presents a methodology to simulate the dispersion of water droplets in the air flow typical of an Icing Tunnel. It is based on the understanding the physical parameters that influence the uniformity and the distribution of cloud of droplets in the airflow and to connect them with analytical parameters which may be used to describe the dispersion process. Specifically it investigates the main geometrical and physical parameters contributing to the droplets dispersion at different tunnel operative conditions, finding a consistent numerical approach to reproduce the local droplets dynamic, quantifying the possible limits of commercial CFD methods, pulling out the empirical parameters/constant needing to simulate properly the local conditions and validating the results with calibrated experiment. An overview of the turbulence and multiphase flow theories, considered relevant to the Icing Tunnel environment, is presented as well as basic concepts and terminology of particle dispersion. Taylor’s theory of particle dispersion has been taken as starting point to explain further historical development of discrete phase dispersion. Common methods incorporated in commercial CFD software are explained and relative shortcomings underlined. The local aerodynamic condition within tunnel, which are required to perform the calculation with the Lagrangian particle equation of motions, are generated numerically using different turbulent models and are compared to the historical K-ε model. Verification of the calculation is performed with grid independency studies. Stochastic Separated Flow methods are applied to compute the particle trajectories. The Discrete Random Walk, as described in the literature, has been used to perform particle dispersion analysis. Numerical settings in the code are related to the characteristics of the local turbulent condition such as turbulence intensity and length scales. Cont/d.

In design and development of aircraft, standard practice uses 'the icing design envelopes' to select atmospheric conditions for modelling icing encounters. Over the duration of these encounters, atmospheric conditions are assumed to be constant and to exhibit no variability. In reality variability exists, to an extent where it may adversely affect the severity of ice accretions beyond that identified by ground-based modelling. Similarly, certain tools and systems employed by industry may sacrifice efficiency & effectiveness in neglecting the variability that exists. This project considered what operational and safety bene ts might be derived from an enhanced knowledge of ice accretion under more realistic, variable conditions; in contrast with a reference case identified to have equivalent constant conditions. In doing so, variable encounters were modelled experimentally in an icing tunnel to compare against a constant-condition reference; aerodynamic penalty was assessed numerically using CFD, allowing a comparison to be made between variable and constant-condition profiles; and desk-research considered variable conditions in the context of existing and emerging technology. Considerable differences were observed between variable profiles themselves and with the reference profile, with aerodynamic penalty being considerably enhanced for 25% of variable cases, and considerably reduced for a further 25%. Desk-research suggests that in understanding variability, to reduce costs asso- iciated with aircraft icing, more realistic ground-based modelling capabilities could reduce the need for natural flight-testing in the long term, though this would require substantial enhancement to current numerical prediction capabilities. Similarly, the power applied to ice protection systems could be tailored more speci cally to demand, enhancing e ciency. On the basis of current instrumentation, this would first require development of more accurate and robust LWC measurement systems. It was therefore recommended that specialists in meteorology, icing physics, ice protection systems and aerodynamics; conduct more extensive research towards understanding variability and assessing its potential to enhance flight-safety, whilst simultaneously reducing cost.

The mechanics and heat transfer of droplet impact is studied in the range of parameters interest for Super-cooled Large Droplet icing. The investigation explores the development of the splash produced experimental and numerically. A Navier-Stokes solver has been developed in order to compare experiments and modelling. Heat transfer is included in the simulations making possible the analysis of the thermal history during the impact of a Super-cooled droplet into a warm and running thin water film. Also a theoretical and numerical study has been undertaken in order to simulate the first stages of ice formation on the critical surfaces of aircraft during the droplet impact under freezing conditions due to super-cooled icing. The parameters considered experimental and numerically are: • Droplet size: 100-700Jlm. • Droplet impact velocity: 18-80m/s. • Angles of impact: 70°,45° and 20°. • Airflow (droplet) temperature: 200 e and _lOoe. • Water film thicknesses: 150Jlm and 50Jlm. • Water film temperature: 15°e and lOoe. • Water film velocity: 5m/s. The simulations are compared to the experiments run under the same conditions. Results for the parameters at the early stages of the splash agree well but as the splash process continues there are more differences between the two sets of results.

The distortion, drag and break-up of drizzle droplets subjected to strong aerodynamic forces was investigated to understand the pre-impact behaviour of droplets in aircraft icing from supercooled freezing drizzle. The objective was to obtain a formulation and data for the drag properties of droplets distorted by the aerodynamic forces, which were beyond the scope of available experimental and modelling methods. A practical and efficient semi-empirical computer model was developed for small water droplets in air, 100μm < D < 500μm, at moderate Reynolds numbers, 350 < Re < 1500, and high Weber numbers 3 < We < 20. This used available experimental terminal velocity data for free-falling droplets, extrapolated to higher Weber numbers, and the numerical solution for sessile droplets on a horizontal unwettable surface, with corrections for the Reynolds number. A theory for bag break-up was developed based on the Rayleigh-Taylor instability of the windward droplet surface. The critical Bond number was 13.7, with a critical diameter of 10.1mm for free-falling water droplets, compared to the experimental value of 10mm diameter. The equivalent Weber number was 14.2 for free falling water droplets. Aerodynamic interaction between the closely-spaced droplets from a vibrating nozzle droplet generator resulted in irregular spacing and coalescence of droplets. In an alternative design a laminar jet impinged on a rotating slotted disk to achieve the necessary droplet spacing, but the significant size variability of the droplets degraded the experimental measurements. High-speed videos, to 50,000pps, and photographs were obtained of droplet distortion, break-up, coalescence and splashes using a high-intensity LED strobe flash. A specially-designed convergent wind tunnel was developed for experimental measurements, to validated the drag model and provide data for droplets distorted by aerodynamic forces. The convergent profile produced a rapidly-increasing Weber number at a sufficiently slow rate to avoid transients or droplet vibrations. A special instrument was developed, with three equispaced parallel laser beams and photo detectors, to determine the droplet velocity and acceleration. Droplet drag characteristics were measured up to Weber numbers of 16. Good agreement was obtained between droplet drag model and experimental results. The greatest discrepancy was about 20% at a Weber number of about 8.