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ITC/USA 2007 Conference Proceedings / The Forty-Third Annual International Telemetering Conference and Technical Exhibition / October 22-25, 2007 / Riviera Hotel & Convention Center, Las Vegas, Nevada / This paper describes the integration activities associated with the instrumentation and telemetry system developed for an F/A-18 Hornet Flight Test program, including bench integration, avionics integration, and aircraft ground and flight checkout. The system is controlled by a Boeing Integrated Defense System (IDS) Flight Test Instrumentation designed Instrumentation Control Unit (ICU), which interfaces to an avionics pilot display and Ground Support Unit (GSU) to set up the instrumentation during preflight and control the instrumentation during flight. The system takes in MIL-STD-1553, analog parameters, Ethernet, Fibre Channel, and video, and records these with onboard recorders. Selected subsets of this data may be routed to the telemetry system, which features two RF streams, each of which contains up to four PCM streams combined into a composite by a data combiner. The RF streams are transmitted by multi-mode digital transmitters capable of PCM-FM or Shaped Offset Quadrature Phase Shift Keying (SOQPSK), with selectable Turbo-Product Code (TPC) Forward Error Correction (FEC). This paper describes integration of the system with the IDS Flight Test Integration Test Bench (ITB), production avionics integration facilities, and final aircraft ground checkout and initial flight tests. It describes results of integration activities and bench evaluation of the telemetry system.

Thesis (MScEng (Mechanical and Mechatronic Engineering))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: This thesis comprises of the testing and evaluation of a modern diesel engine running on both biodiesel and mineral diesel on the upgraded Bio-fuels Testing Facility (BTF) at Stellenbosch University. The project was motivated by the need to install a modern diesel engine onto the existing BTF test rig for biodiesel testing. In this project, the BTF was re-designed to support a new Volkswagen 1.9L TDI engine. The capabilities of the BTF were then expanded further by the implementation of a low-cost pressure indicating system, utilising an optical pressure transducer. During the testing of biodiesel, it was found that the calorific value of the biodiesel was 14% lower than that of the tested mineral diesel. The ignition quality (cetane index) of the biodiesel was also lower than that of the mineral diesel. Even so, the engine only experienced a maximum power loss of 4.2%. During heat-release analysis, it was determined that there was no significant difference in the combustion process of biodiesel and that of mineral diesel. The conclusion could be made that biodiesel is suitable for use in modern TDI engines. Testing validated the operation of the upgraded test cell, and in trials it was determined that the test results are highly repeatable. The pressure indicating set proved to have some limitations. Only simplified heat-release analyses and reasonable indicated power calculations could be performed with the indicating set. Recommendations were made for improvement in future research. / Centre for Renewable and Sustainable Energy Studies

Cette thèse traite du problème de l'égalisation des modulations codées pour les transmissions haut-débit sur canaux sélectifs en fréquence, sujets au phénomène d'interférence entre symboles. Nous considérons plus particulièrement la Turbo-Égalisation, qui instaure un échange réciproque d'information entre l'égaliseur et le décodeur, et ce de manière itérative. Nous étudions dans un premier temps le turbo-égaliseur MAP, qui utilise un égaliseur optimal au sens de la minimisation de la p probabilité d'erreur par symbole. Nous montrons que ce récepteur offre des gains de performances importants en comparaison avec les récepteurs conventionnels où les opérations d'égalisation et décodage sont généralement effectuées de manière disjointe. En contrepartie, la complexité du turbo-égaliseur MAP devient rapidement prohibitive en présence de modulations à grand nombre d'états et sur des canaux présentant des étalements temporels importants. En conséquence, nous nous intéressons à une seconde classe de turbo-égaliseurs de moindre complexité et reposant sur des égaliseurs à base de filtres linéaires, optimisés selon le critère MEQM. La nouveauté consiste ici à prendre en compte explicitement la présence d'information a priori dans le calcul des coefficients des filtres, ce qui conduit à des structures bien plus performantes que les égaliseurs MEQM classiques. Nos études montrent que ce type de récepteur constitue une solution attractive pour les transmissions à grande efficacité spectrale sur canaux sélectifs en fréquence. Finalement, nous présentons la mise en oeuvre d'un turbo-égaliseur MEQM sur un DSP virgule-fixe et faible coût, le TMS320VC5509, typiquement destiné aux terminaux mobiles. Nous obtenons ainsi un débit utile de 42 Kbits/s après 5 itérations avec une implémentation en langage C, ce qui démontre la faisabilité de tels récepteurs avec les moyens technologiques actuels.

The upcoming 5G mobile communications system promises to enable use cases requiring ultra-reliable and low latency communications. Researchers therefore require more detailed information about aspects such as channel coding performance at very low block error rates. The simulations needed to obtain such results are very time consuming and this poses achallenge to studying the problem. This thesis investigates the use of hardware acceleration for performing fast simulations of turbo code performance. Special interest is taken in investigating different methods for generating normally distributed noise based on pseudorandom number generator algorithms executed in DSP:s. A comparison is also done regarding how well different simulator program structures utilize the hardware. Results show that even a simple program for utilizing parallel DSP:s can achieve good usage of hardware accelerators and enable fast simulations. It is also shown that for the studied process the bottleneck is the conversion of hard bits to soft bits with addition of normally distributed noise. It is indicated that methods for noise generation which do not adhere to a true normal distribution can further speed up this process and yet yield simulation quality comparable to methods adhering to a true Gaussian distribution. Overall, it is show that the proposed use of hardware acceleration in combination with the DSP software simulator program can in a reasonable time frame generate results for turbo code performance at block error rates as low as 10−9.

Os motores de foguetes baseados em ciclos combinados têm sido largamente discutidos e aplicados nos sistemas de propulsão de veículos lançadores reutilizáveis devido ao fato de apresentarem baixa relação empuxo x peso e elevado impulso específico, podendo assim ampliarem a carga útil transportada. Este trabalho tem por finalidade explanar a variedade de motores de foguetes baseados em ciclos combinados. E dentro desta perspectiva apresentar um estudo de um motor de ciclo combinado que é híbrido entre motor turbo-foguete e propulsão aspirada, denominado motor turbo-foguete aspirado - ATR como uma proposta de motor auxiliar reutilizável para veículos lançadores de satélites. A análise do motor turbo-foguete aspirado proposto será feita através do desenvolvimento de uma metodologia computacional baseada em linguagem de programação orientada a objeto (C++) e o código aberto Cantera (GOODWIN, 2002). Esta análise consiste na obtenção de dados termodinâmicos e parâmetros de seus componentes para a configuração do motor ATR proposto, de modo que venha facilitar o desenvolvimento do projeto do motor do tipo ATR. Ao término deste trabalho ter-se-á uma ferramenta de análise do motor ATR bem como demais motores que apresentem a propulsão aspirada em seu sistema de propulsão.

Since the late 19th century, the average temperature on Earth has risen by approximately 1.1 °C because of the increased carbon dioxide (CO2) and other man-made emissions to the atmosphere. The transportation sector is responsible for approximately 33% of the global CO2 emissions and 14% of the overall greenhouse gas emissions. Therefore, increasingly stringent regulations in the European Union require CO2 emissions to be lower than 95 gCO₂/km by 2020. In this regard, improvements in internal combustion engines (ICEs)must be achieved in terms of fuel consumption and CO2 emissions. Given that only up to 35% of fuel energy is converted into mechanical power, the wasted energy can be reused through waste heat recovery (WHR) technologies. Consequently, organic Rankine cycle (ORC) has received significant attention as a WHR technology because of its ability to recover wasted heat in low- to medium-heat sources. The Expansion machine is the key component in ORC systems, and its performance has a direct and significant impact on overall cycle efficiency. However, the thermal efficiencies of ORC systems are typically low due to low working temperatures. Moreover, supersonic conditions at the high pressure ratios are usually encountered in the expander due to the thermal properties of the working fluids selected which are different to water. Therefore, this thesis aims to design an efficient radial-inflow turbine to avoid further efficiency reductions in the overall system. To fulfil this aim, a novel design and optimisation methodology was developed. A design of experiments technique was incorporated in the methodology toexplorethe effects of input parameters on turbine performance and overall size. Importantly, performance prediction modelling by means of 1D mean-line modelling was employed in the proposed methodology to examine the performance of ORC turbines at constant geometries. The proposed methodology was validated by three methods: computational fluid dynamics analysis, experimental work available in the literature, and experimental work in the current project. Owing to the lack of actual experimental works in ORC-ICE applications, a test rig was built around a heavy-duty diesel engine at Brunel University London and tested at partial load conditions due to the requirement for a realistic off-high representation of the performance of the system rather than its best (design) point, while taking into account the limitation of the engine dynamometer employed. Results of the design methodology developed for this projectpresented an efficient single-stage high-pressure ratio radial-inflow turbine with a total to static efficiency of 74.4% and an output power of 13.6 kW.Experimental results showed that the ORC system had a thermal efficiency of 4.3%, and the brake-specific fuel consumption of the engine was reduced by 3%. The novel meanlineoff designcode (MOC) was validated with the experimental works from three turbines. In comparison with the experimental results conducted at Brunel University London, the predicted and measured results were in good agreement with a maximum deviation of 2.8%.

In der vorliegenden Arbeit wird die Steifigkeits- und Festigkeitsauslegung von mittels der Tailored Fiber Placement (TFP)-Technologie hergestellten Faser-Kunststoff-Verbunden (FKV) am Beispiel eines einteiligen Rotors aus kohlenstofffaserverstärktem Epoxidharz (CFK) für den Einsatz in Turbomolekularpumpen (TMP) vorgestellt. Im Vergleich zu anderen textilen Fertigungsverfahren können mit Hilfe der TFP-Technologie Verstärkungsfaserrovings in der Ebene variabelaxial, d. h. mit ortsunabhängiger, frei wählbarer Richtung, definiert abgelegt werden. Die sticktechnische Fixierung der Rovings mit Hilfe eines Nähfadens führt zu Welligkeiten und Materialinhomogenitäten in TFP-basierten Faser-Kunststoff-Verbunden (FKV). Dadurch werden die Materialeigenschaften beeinflusst. Mit Hilfe einer Prozessanalyse in Kombination mit morphologischen Untersuchungen werden in dieser Arbeit die welligkeitsinduzierenden Effekte in TFP-basierten FKV identifiziert und quantifiziert. Darauf aufbauend wird ein mesoskaliges Repräsentatives Volumenelement (RVE) einer TFP-Einheitszelle auf Basis von Finiten Elementen entwickelt. Mit Hilfe des RVE wird es erstmalig ermöglicht, die Dehnungs- und Spannungsverteilung sowie den lokalen Faservolumengehalt in TFP-basierten FKV zu berechnen und daraus wirklichkeitsnahe Materialkennwerte abzuleiten. Darüber hinaus wird anhand des RVE der Einfluss variierender TFP-Prozessparameter auf die resultierenden Steifigkeits- und Festigkeitseigenschaften analysiert. Weiterhin wird der Einfluss des unter Langzeitbelastung eintretenden Matrixkriechens auf die Materialeigenschaften von TFP-basierten FKV untersucht. Anhand der Entwicklungsschritte eines CFK-TMP-Rotordemonstrators werden die Besonderheiten beim Auslegungsprozess für Bauteile aus TFP-Strukturen verdeutlicht. Neben der Erläuterung der Lastfälle von TMP-Rotoren wird die Entwicklung eines lastfallangepassten Faserlayouts unter Berücksichtigung von geometrischen Restriktionen beschrieben. Im Rahmen der Spannungsanalyse auf Basis der Finite Elemente Methode (FEM) erfolgt die Integration der mittels des RVE bestimmten Materialdaten in das FE-Modell schichtweise, entsprechend der verwendeten TFP-Prozessparameter. Die mit dieser Vorgehensweise berechnete Versagensdrehzahl und die ermittelten Eigenfrequenzen konnten in experimentellen Untersuchungen erfolgreich validiert werden. Durch die Integration der ortsaufgelösten RVE-basierten Materialdaten wird erstmalig nicht nur die Struktursteifigkeit, sondern auch die Festigkeit ausgehend von einem variabelaxialen TFP-Ablagemuster in einem TFP-basierten Bauteil vorhergesagt. Mit dem entwickelten TMP-Rotordemonstrator kann die Versagensdrehzahl gegenüber dem Stand der Technik um 45 % gesteigert werden. In der Arbeit wird auch herausgestellt, welche Änderungen der Geometrie von TMP-Rotoren aus FKV nötig sind, um eine werkstoffgerechte, an die orthotropen Eigenschaften von FKV angepasste Gestaltung zu realisieren und damit die Nenndrehzahlen weiter steigern zu können. Diese Erkenntnisse dienen in verallgemeinerter Weise der werkstoffgerechten Auslegung und Fertigung von TFP-basierten FKV-Bauteilen. / The present work demonstrates the stiffness and strength design of fiber reinforced plastics (FRP) made by the Tailored Fiber Placement (TFP) technology using the example of a a turbo molecular pump (TMP) rotor made of carbon fiber reinforced epoxy resin (CFRP). In contrast to other textile preform manufacturing processes, the TFP technology enables the placement of reinforcement rovings in arbitrary direction according to an user defined design path. In this technology a double locked stitch in a zigzag stitch pattern is used to fixate the rovings. The fixation process leads to waviness and material inhomogeneities within the placed rovings resulting in reduced material properties in TFP-based fiber reinforced plastics. The wavinessinducing effects have been identified and quantified by detailed process analysis and morphological investigations. Subsequently, a meso-scaled representative volume element (RVE) of a TFP unit cell based on finite elements was developed. The RVE provides the opportunity to derive realistic material properties by calculating the stress and strain distribution as well as as the local fiber content in TFP-based FRP. In this work, the influence of different TFP process parameters on the resulting modulus and strength has been investigated using the RVE approach. Additionally, long term loading effects leading to a reduced matrix modulus were analyzed numerically with the RVE. Based on the development of the CFRP TMP rotor specific characteristics of the design process for components made of TFP are clarified. Besides the explanation of loading conditions of TMP rotors the progress of a load-adapted fiber layout considering geometrical restrictions is demonstrated. For the stress analysis based on the Finite Element Method (FEM) material data calculated with the RVE according to the applied TFP process parameters have been integrated into the FE model. The numerically determined failure speed and the calculated eigenfrequencies were successfully validated by experimental tests. By implementing TFP specific material data in the FE model, both, the strucural rigidity as well as the strength, were predicted for the first time in a TFP-based component. Compared to the state-of-the-art, the developed TMP rotor offers an increased failure speed by 45 %. Furthermore necessary geometric modifications for FRP based TMP rotors in order to achieve a material-specific design adapted to the orthotropic material properties and thus to further increase the nominal rotational speeds were shown. These findings provide in a generalized way for a material-specific design of TFP-based FRP components.

Les systèmes de téléphonie mobile de 4ème et 5ème générations ont adopté comme techniques de codage de canal les turbocodes, les codes LDPC et les codes polaires binaires. Cependant, ces codes ne permettent pas de répondre aux exigences, en termes d’efficacité spectrale et de fiabilité, pour les réseaux de communications futurs (2030 et au-delà), qui devront supporter de nouvelles applications telles que les communications holographiques, les véhicules autonomes, l’internet tactile … Un premier pas a été fait il y a quelques années vers la définition de codes correcteurs d’erreurs plus puissants avec l’étude de codes LDPC non binaires, qui ont montré une meilleure performance que leurs équivalents binaires pour de petites tailles de code et/ou lorsqu'ils sont utilisés sur des canaux non binaires. En contrepartie, les codes LDPC non binaires présentent une complexité de décodage plus importante que leur équivalent binaire. Des études similaires ont commencé à émerger du côté des turbocodes. Tout comme pour leurs homologues LDPC, les turbocodes non binaires présentent d’excellentes performances pour de petites tailles de blocs. Du point de vue du décodage, les turbocodes non binaires sont confrontés au même problème d’augmentation de la complexité de traitement que les codes LDPC non binaire. Dans cette thèse nous avons proposé une nouvelle structure de turbocodes non binaires en optimisant les différents blocs qui la constituent. Nous avons réduit la complexité de ces codes grâce à la définition d’un algorithme de décodage simplifié. Les codes obtenus ont montré des performances intéressantes en comparaison avec les codes correcteur d’erreur de la littérature. / Nowadays communication standards have adopted different binary forward error correction codes. Turbo codes were adopted for the long term evolution standard, while binary LDPC codes were standardized for the fifth generation of mobile communication (5G) along side with the polar codes. Meanwhile, the focus of the communication community is shifted towards the requirement of beyond 5G standards. Networks for the year 2030 and beyond are expected to support novel forward-looking scenarios, such as holographic communications, autonomous vehicles, massive machine-type communications, tactile Internet… To respond to the expected requirements of new communication systems, non-binary LDPC codes were defined, and they are shown to achieve better error correcting performance than the binary LDPC codes. This performance gain was followed by a high decoding complexity, depending on the field order.Similar studies emerged in the context of turbo codes, where the non-binary turbo codes were defined, and have shown promising error correcting performance, while imposing high complexity. The aim of this thesis is to propose a new low-complex structure of non-binary turbocodes. The constituent blocks of this structure were optimized in this work, and a new low complexity decoding algorithm was proposed targeting a future hardware implementation. The obtained results are promising, where the proposed codes are shown to outperform existing binary and non-binary codes from the literature.