Effects of Boundary Layer Ingestion on the Aero-Acoustics of Transonic Fan Rotors

The use of boundary-layer-ingesting, embedded propulsion systems can result in inlet flow distortions where the interaction of the boundary layer vorticity and the inlet lip causes horseshoe vortex formation and the ingestion of streamwise vortices into the inlet. A previously-developed body-force-based fan modeling approach was used to assess the change in fan rotor shock noise generation and propagation in a boundary-layer-ingesting, serpentine inlet. This approach is employed here in a parametric study to assess the effects of inlet geometry parameters (offset-to-diameter ratio and downstream-to-upstream area ratio) on flow distortion and rotor shock noise. Mechanisms related to the vortical inlet structures were found to govern changes in the rotor shock noise generation and propagation. The vortex whose circulation is in the opposite direction to the fan rotation (counter-swirling vortex) increases incidence angles on the fan blades near the tip, enhancing noise generation. The vortex with circulation in the direction of fan rotation (co-swirling vortex) creates a region of subsonic relative flow near the blade tip radius which decreases the sound power propagated to the far-field. The parametric study revealed that the overall sound power level at the fan leading edge is set by the ingested streamwise circulation, and that for inlet designs in which the streamwise vortices are displaced away from the duct wall, the sound power at the upstream inlet plane increased by as much as 9 dB. By comparing the far-field noise results obtained to those for a conventional inlet, it is deduced that the changes in rotor shock noise are predominantly due to the ingestion of streamwise vorticity.

Współpraca transgraniczna i regionalna w obszarze Morza Bałtyckiego w latach 1989 -2007

Wydział Nauk Politycznych i Dziennikarstwa

Teaching Crossroads: 11th IPB Erasmus Week

In the wake of the latest news regarding IPB’s award for best Polytechnic Institute in Portugal, we would like to congratulate the IPB community who has always striven for the quality of the institution within the national and international academic milieu. We are, undoubtedly, bowled over by the 1st place in the national context (out of the 27 national institutions under evaluation) and the 7th position in the international scope. In fact, it is worth mentioning that the IPB has won this award, three years in a row, being in a leading position in the ranking promoted and sponsored by the European Union. This year’s edition has selected and evaluated over 1300 world higher education institutions. Teaching Crossroads intends thus to give a watershed contribution to the IPB’s successful and most valued pathway. Numbers indicate that Teaching Crossroads has had over 2550 downloads since it first came out. But let’s cut to the chase. Once again, we are delighted to present the 5th number of Teaching Crossroads. This wholly calculated and well-sustained editorial adventure started in 2012 when the first number of Teaching Crossroads first saw the light. This year’s publication includes the areas of Human Geography/anthropology, Information Technology and Forensics and Language and culture, focusing on minority languages. Alongside this, as in the two last previous numbers, we’ve included the specific area for International mobility, Intensive Programmes and Erasmus+ Mobility of Individuals, being the latter financed by the European Union within the Erasmus+ Programme, whereas the former is sponsored uniquely by the foreign partner institution, in this case, Lillebaelt Academy in Denmark. These types of programmes convey very positive and overarching ideas, resonant in cross-cultural and educational benefits, valuable for all the involved partners. We would very kindheartedly like to thank the authors for having contributed with much enlightening and serious articles on a wide array of areas. Pablo M. Orduna Pórtus’s article focuses on border culture and heritage management. The author’s study is placed on two borderlands of the Iberian Peninsula: Roncal Valley (Navarre) and Riverbanks of Douro. Going beyond the linear or physical conception of the border, the author centres his study on the metaphysical and symbolic ideas of the frontier that sustain his anthropological analysis. Michal Popdora manages to find evidence for his proposal of a new conception of teaching Image Processing, based on the student-centered approach. A hands-on experience on a Project-based Learning methodology sustains the teaching project. Grounded on “a forensic-flavored style”, using the author’s own words, he shows how students can become engaged in a highly effective learning process. Cláudia Martins is already a confirmed habitué of this publication, as in every Erasmus Week she delivers a lecture on Portuguese language and culture to visiting teaching and non-teaching staff. This time, the author decided to delve into a Portugal’s official language, Mirandese, spoken in a small designated area in the northeastern part of Portugal, Miranda do Douro and its surrounding area. The author gives account of some thought-provoking facts about the language, from the origin and the survival of the language, however still a minority language, up to the moment when it was acknowledged Portugal’s second official language, together with the challenges that nowadays faces. Luís Frölen Ribeiro, João Eduardo Ribeiro, Carlos Casimiro Costa, António Duarte, Carlos Andrade from the Polytechnic Institute and Arne Svinth, John Madsen, Morten Thomsen, Kent Smidstrup, Carsten John Jacobsen from the Lillebaelt Academy, in Denmark, participate in a joint project which they describe, outlining the main goals and gains of the project. To overcome teaching difficulties regarding the engineering degrees, a 12-ECTS joint course from Lillebaelt Academy and Polytechnic Institute of Bragança was created based on the Danish model. The course Product Development and Industrial Processing was hence created. Rui Pedro Lopes presents an insightful and acute account of the Internationalization programmes in Higher Education in Europe. At one go, the author describes his own experience as a visiting lecturer, within the Erasmus+ programme, to Università Politecnica delle Marche in Ancona, Italy, in a Master’s degree in computer science, bringing to light a personal reflection on the goals and benefits of the mobility for both students and teachers. Finally, the author puts forth some suggestions that would improve the whole mobility process. We sincerely hope to have stimulated you to keep on reading, upholding the belief that these texts can represent valuable sources for both teachers and students in their research work.

Energy harvesting embedded wireless sensor system for building environment applications

For many wireless sensor networks applications, indoor light energy is the only ambient energy source commonly available. Many advantages and constraints co-exist in this technology. However, relatively few indoor light powered harvesters have been presented and much research remains to be carried out on a variety of related design considerations and trade-offs. This work presents a solution using the Tyndall mote and an indoor light powered wireless sensor node. It analyses design considerations on several issues such as indoor light characteristics, solar panel component choice, maximum power point tracking, energy storage elements and the trade-offs and choices between them.

Uncertainty in wind energy forecasting

Wind energy is the energy source that contributes most to the renewable energy mix of European countries. While there are good wind resources throughout Europe, the intermittency of the wind represents a major problem for the deployment of wind energy into the electricity networks. To ensure grid security a Transmission System Operator needs today for each kilowatt of wind energy either an equal amount of spinning reserve or a forecasting system that can predict the amount of energy that will be produced from wind over a period of 1 to 48 hours. In the range from 5m/s to 15m/s a wind turbine’s production increases with a power of three. For this reason, a Transmission System Operator requires an accuracy for wind speed forecasts of 1m/s in this wind speed range. Forecasting wind energy with a numerical weather prediction model in this context builds the background of this work. The author’s goal was to present a pragmatic solution to this specific problem in the ”real world”. This work therefore has to be seen in a technical context and hence does not provide nor intends to provide a general overview of the benefits and drawbacks of wind energy as a renewable energy source. In the first part of this work the accuracy requirements of the energy sector for wind speed predictions from numerical weather prediction models are described and analysed. A unique set of numerical experiments has been carried out in collaboration with the Danish Meteorological Institute to investigate the forecast quality of an operational numerical weather prediction model for this purpose. The results of this investigation revealed that the accuracy requirements for wind speed and wind power forecasts from today’s numerical weather prediction models can only be met at certain times. This means that the uncertainty of the forecast quality becomes a parameter that is as important as the wind speed and wind power itself. To quantify the uncertainty of a forecast valid for tomorrow requires an ensemble of forecasts. In the second part of this work such an ensemble of forecasts was designed and verified for its ability to quantify the forecast error. This was accomplished by correlating the measured error and the forecasted uncertainty on area integrated wind speed and wind power in Denmark and Ireland. A correlation of 93% was achieved in these areas. This method cannot solve the accuracy requirements of the energy sector. By knowing the uncertainty of the forecasts, the focus can however be put on the accuracy requirements at times when it is possible to accurately predict the weather. Thus, this result presents a major step forward in making wind energy a compatible energy source in the future.

Market-oriented new product development of functional beverages

Strategic reviews of the Irish Food and Beverage Industry have consistently emphasised the need for food and beverage firms to improve their innovation and marketing capabilities, in order to maintain competitiveness in both domestic and overseas markets. In particular, the functional food and beverages market has been singled out as an extremely important emerging market, which Irish firms could benefit from through an increased technological and market orientation. Although health and wellness have been the most significant drivers of new product development (NPD) in recent years, failure rates for new functional foods and beverages have been reportedly high. In that context, researchers in the US, UK, Denmark and Ireland have reported a marked divergence between NPD practices within food and beverage firms and normative advice for successful product development. The high reported failure rates for new functional foods and beverages suggest a failure to manage customer knowledge effectively, as well as a lack of knowledge management between functional disciplines involved in the NPD process. This research explored the concept of managing customer knowledge at the early stages of the NPD process, and applied it to the development of a range of functional beverages, through the use of advanced concept optimisation research techniques, which provided for a more market-oriented approach to new food product development. A sequential exploratory research design strategy using mixed research methods was chosen for this study. First, the qualitative element of this research investigated customers’ choice motives for orange juice and soft drinks, and explored their attitudes and perceptions towards a range of new functional beverage concepts through a combination of 15 in-depth interviews and 3 focus groups. Second, the quantitative element of this research consisted of 3 conjoint-based questionnaires administered to 400 different customers in each study in order to model their purchase preferences for chilled nutrient-enriched and probiotic orange juices, and stimulant soft drinks. The in-depth interviews identified the key product design attributes that influenced customers’ choice motives for orange juice. The focus group discussions revealed that groups of customers were negative towards the addition of certain functional ingredients to natural foods and beverages. K-means cluster analysis was used to quantitatively identify segments of customers with similar preferences for chilled nutrient-enriched and probiotic orange juices, and stimulant soft drinks. Overall, advanced concept optimisation research methods facilitate the integration of the customer at the early stages of the NPD process, which promotes a multi-disciplinary approach to new food product design. This research illustrated how advanced concept optimisation research methods could contribute towards effective and efficient knowledge management in the new food product development process.

Echoes of existentialism in the works of Carlos Fuentes

In this thesis I have set out to trace the echoes of existentialism in the work of the Mexican novelist, Carlos Fuentes scrutinizing, in particular, La región más transparente, La muerte de Artemio Cruz and Cambio de piel. In the opening segment of the thesis I outline the essential tenets of existentialist thought and how it became the predominant philosophical and literary movement of the early part of the twentieth-century. Stemming from the work of Sören Kierkegaard in Denmark towards the end of the nineteenth-century, it challenged the arid philosophies of previous generations and provided a new way of looking at man and the human condition. In this opening chapter, I study the works of the more important philosophers in this regard such as Heidegger, Sartre, Jaspers, Marcel, Unamuno, and Ortega y Gasset and show how each in his own way contributed to the further development of the new philosophy. Chapter 2 is concerned with the spread of existentialism to the Latin American continent. In the early part of the twentieth-century, Mexico was emerging from a turbulent revolutionary period and seeking a solution to the fractured nature of its society. The Spanish philosopher, Ortega y Gasset, and the many Spanish intellectuals who sought refuge from Franco’s dictatorship in Mexico, helped to popularise the new philosophy and these lively debates about existentialism served to underpin ideas around mexicanidad or Mexican national identity. Carlos Fuentes was deeply immersed in the debate of his time, positioned as he was as a prominent public intellectual. In La muerte de Artemio Cruz he shows us how great wealth and power are a poor recompense for the loss of love and compassion and lead only to alienation and selfishness. In his other best known novel, La región más transparente, he explores the rise of modern Mexico and its society – an inauthentic society that is corrupted by a scramble for wealth and self-aggrandizement. The final chapter is devoted to the study of Cambio de piel which is concerned with violence and alienation as central pillars of existence. The violence depicted here precipitates a crisis in the human condition and an accompanying sense of alienation. The thesis seeks to establish that existentialism is central not only to Fuentes’s literary concerns but also forms a part of his ethics as an artist.