Dissertations / Theses: 'Schlieren method'

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Kotrík, Marcel. "Vliv ochranné atmosféry na vlastnosti svaru při kondukčním laserovém svařování plechů z konstrukční uhlíkové oceli." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2019. http://www.nusl.cz/ntk/nusl-399298.

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In the thesis are analysed influences of three shield gases, based on literary pursuit. Compared was influence of the gas consisting of pure Ar, mixture Ar with 3vol.% CO2 and the mixture Ar with 18vol.% CO2 on mechanical properties of conduction laser welded blunt welds made from structural steel DC01 and S235JR with thickness 3mm and 2mm. Compared were strength properties of the welds in tension, weld hardness and hardness of the heat affected area under the low stress. Further was observed and compared stream of the gases during welding process and its influences on the appearance of the trial welds. On the metallographical cuts of the welds were evaluated mistakes and dimensions of the welds.

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Vieira, Marcelo Mendes. "Estudo experimental de jatos evaporativos." Universidade de São Paulo, 1999. http://www.teses.usp.br/teses/disponiveis/3/3132/tde-11042002-132126/.

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Foi construído um arranjo experimental para estudar o comportamento dos jatos evaporativos. Um injetor foi projetado para controlar e manter constantes a pressão e temperatura de reservatório durante a injeção. Um bocal cônico convergente de seção reta com diâmetro de saída de 0,30 mm e ângulo entre sua geratriz e seu eixo simetria igual à 10º forma o elemento principal do injetor. O jato é descarregado em uma câmara de baixa pressão de dimensões suficientemente grandes para manter a pressão constante durante o curto período de ensaio, igual à 1 s. Quando injetado, o líquido sofre uma repentina queda de pressão ocasionando sua evaporação. Os fluidos utilizados são os combustíveis querosene e óleo diesel, e a substância n-dodecano, os quais se caracterizam pela possibilidade de uma evaporação completa, de forma adiabática. Utilizou-se o método \"schlieren\" para a visualização do escoamento. A análise dos jatos é feita de forma qualitativa através dos registros fotográficos. Foram observados os seguintes tipos de jato: (1) contínuo, (2) pulverizante e (3) evaporação na superfície. O primeiro jato não implica em imediata mudança de fase tornando o jato de líquido emergente intacto. Com o aumento da temperatura de injeção, existe o espalhamento e a evaporação do jato, formando o segundo tipo de jato, onde é possível visualizar o campo do gradiente de densidade do escoamento e a formação de ondas de evaporação e de choque que pode ocorrer a uma distância proporcional a vários diâmetros à jusante. Em jatos com evaporação completa, foram constadas a formação de ondas de choque tanto de formas elipsóide como de esferóide para elevadas temperaturas. As fotografias digitais são submetidas à filtragem e processamento matemático para melhor destacar tais fenômenos do escoamento.
An experimental apparatus has been built to study the behaviour of flashing jets. An injector was designed to control and maintain the jet pressure and temperature at constant values during the injection process. A conical convergent nozzle whose main dimensions are 0,30 mm of exit diameter, 8 mm long, and a convergence half-angle of 10º is the central component of the injection system. The jet is discharged into a low-pressure chamber large enough to keep the reservoir pressure constant during the short test period of about 1 s. As the testing liquid expands in the nozzle it undergoes a sudden pressure drop causing its evaporation. The fluids are usual fuels, such as kerosene and diesel oil, and the substance ndodecane, which are distinguishable by the possibility of a complete evaporation in an isoentropic expansion process. The photographic method \"schlieren\" is used for flow visualisation. A qualitative analysis is made of the photographic documentation of the images obtained using a CCD camera. The images can be grouped into three categories of jets: (1) continuous, (2) shattering, and (3) with surface evaporation. The first regime has an undisturbed a liquid column, which remains more or less intact during the injection process. In the second type, the existing liquid jet is shattered by vapour nucleation and, in some cases, shock waves are clearly visible. It happens at higher temperature than the preceding evaporation mode. Finally, in special situations, the jet undergoes an evaporation at its surface and the two-phase mixture expands at a high speed followed by a shock wave before the mixture attains the pressure reservoir.

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Mlynski, Michael Frank. "Eine neue Methode des unscharfen Schließens für Expertensysteme." Aachen : Klinkenberg, 2003. http://deposit.d-nb.de/cgi-bin/dokserv?idn=967853923.

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Carnell, Mark Thomas. "The application of optical diagnostics to high energy electromagnetic acoustic transducers." Thesis, Loughborough University, 1995. https://dspace.lboro.ac.uk/2134/11239.

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This thesis is concerned with the design and construction of an electromagnetic acoustic transducer (EMAT) and the characterisation of its acoustic field both conventionally, using a hydrophone and with high resolution laser illuminated schlieren techniques. During the early 80s the introduction of the EMA T along with the other types of shock wave source used for lithotripsy, revolutionised the treatment of stone disease. The process of shock wave induced destruction of calculi and the use of shock waves in other areas of medicine will be discussed, along with the causes and effects of stone disease in man. For the first time high temporal and spatial resolution schlierenimages of the shock waves and there interaction with simulation kidney stones have been recorded. The technique provides a clearer picture of the fragmentation process and may assist research into the suitability of shock wave treatment in other areas of medicine currently under investigation. Schlieren studies of the acoustic field have shown the complex structure of not only the EMA T shock wave, but also that associated with cavitation in the field. The primary source of cavitation is due to the rupture and subsequent collapse of bubbles generated in the water by the strong rarefaction phase of the shock wave. The images give evidence for the interaction of these 'primary' cavitation shocks with bubbles in the field, the collapse of some of these bubbles giving rise to additional or 'secondary' cavitation shocks. An optical lensing effect introduced by the shock has also been investigated. Objects seen through or immersed in the field of an EMAT shock wave such as cavitation, appear highly distorted, due to the strong positive and negative lensing effects associated with the changing refractive index of the compression and rarefaction cycles of the shock wave.

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Domens, Pierre. "Contribution a l'étude des décharges électriques dans les grands intervalles d'air." Pau, 1987. http://www.theses.fr/1987PAUU3011.

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Etude par strioscopie de la phase leader des décharges positives dans les grands intervalles d'air soumis a une sonde manœuvre. Résultats expérimentaux en mode image par image et balayage. Etude expérimentale et modélisation des streamers sous tension continue et sous tension impulsionnelle. Calcul de la répartition spatio-temporelle de la charge de tête, des courants a l'électrode haute tension et du champ au plan. Extension du modèle aux grandes distances

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Mlynski, Michael Frank [Verfasser]. "Eine neue Methode des unscharfen Schließens für Expertensysteme / vorgelegt von Michael Frank Mlynski." Aachen : Klinkenberg, 2003. http://d-nb.info/967853923/34.

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Todoroff, Violaine. "Mesure d’un champ de masse volumique par Background Oriented Schlieren 3D. Étude d’un dispositif expérimental et des méthodes de traitement pour la résolution du problème inverse." Phd thesis, Toulouse, INPT, 2013. http://oatao.univ-toulouse.fr/11303/1/todoroff.pdf.

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Ces travaux consistent à mettre en place un dispositif expérimental BOS3D permettant la reconstruction du champ de masse volumique instantané d'un écoulement ainsi qu'à développer un algorithme de reconstruction permettant une mise à disposition rapide des résultats ainsi qu'une robustesse liée à un nombre faible de points de vue. La démarche a consisté dans un premier temps à développer un algorithme de reconstruction BOS3D applicable à toutes les configurations expérimentales. Pour cela, le problème direct a été reformulé sous forme algébrique et un critère a été défini. Cette formulation ainsi que les équations issues des méthodes d'optimisation nécessaires à la minimisation du critère ont été parallélisés pour permettre une implémentation sur GPU. Cet algorithme a ensuite été testé sur des cas de références issus de calcul numérique afin de vérifier si le champ reconstruit par l'algorithme était en accord avec celui fourni. Dans ce cadre, nous avons développé un outil permettant de simuler numériquement une BOS3D afin d'obtenir les champs de déviation associées aux écoulements numériques. Ces champs de déviation ont ensuite été fournis comme entrée au code et nous ont permis d'étudier la sensibilité de notre algorithme à de nombreux paramètres tels que le bruit sur les données, les erreurs de calibration, la discrétisation du maillage... Ensuite, afin de tester notre code sur des données réelles nous avons mis en place un banc expérimental BOS3D pour la reconstruction du champ de masse volumique instantané. Cela a nécessité l'étude d'un nouveau moyen de mesure, faisant appel à des techniques de calibrage multi-caméras et de nouvelles stratégies d'illumination su fond. Finalement les données issues de l'expérimentation ont été utilisées comme entrée de notre algorithme afin de valider son comportement sur données réelles.

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Janßen, Paola [Verfasser]. "Schließen mit Erfahrungssätzen : Untersuchung des Zusammenhangs zwischen statistischen und juristischen Methoden der Überzeugungsbildung / Paola Janßen." Baden-Baden : Nomos Verlagsgesellschaft mbH & Co. KG, 2021. http://d-nb.info/1237168201/34.

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Balzer, Jan. "IT-unterstützte Unternehmensanalyse : Grundlagen, Methoden und Konzept für einen fallbasierten Ansatz /." Saarbrücken : VDM, Müller, 2006. http://deposit.d-nb.de/cgi-bin/dokserv?id=2871771&prov=M&dok_var=1&dok_ext=htm.

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Procházka, Libor. "Studium vlivu ochranné atmosféry na kvalitu svaru a parametry laserového svařování." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2017. http://www.nusl.cz/ntk/nusl-317188.

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The subject of this diploma thesis is the use of laser welding technology in protective atmospheres. Based on the literary research presented in the theoretical part of the thesis, two experiments were made. Welding of materials X5CrNi18-10 and X2CrNiMo17-13-2. Welded sheets were performed in three different protective atmospheres. Samples were made from the welded sheets for measuring tensile strength, hardness, macrostructure and microstructure. These samples were analyzed. The output of the analysis is the evaluation of the impact that the protective atmosphere have on the quality of the welded joint and optimal process parameters.

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Todoroff, V. "Mesure d'un champ de masse volumique par Background Oriented Schlieren 3d. Etude d'un dispositif expérimental et des méthodes de traitement pour la résolution du problème inverse." Phd thesis, Institut National Polytechnique de Toulouse - INPT, 2013. http://tel.archives-ouvertes.fr/tel-01020975.

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Cette thèse consiste à mettre en place un dispositif scientifique expérimental BOS3D (Background Oriented Schlieren 3D) à l'ONERA permettant la reconstruction du champ de masse volumique instantané d'un écoulement ainsi qu'à développer un algorithme robuste de reconstruction permettant une mise à disposition rapide des résultats considérant un nombre faible de points de vue. Dans un premier temps, nous avons développé un algorithme de reconstruction BOS3D applicable à toutes les configurations expérimentales. Pour cela, le problème direct, c'est-à-dire l'équation de la déviation des rayons lumineux à travers un milieu d'indice optique non homogène, a été reformulé sous forme algébrique. Un critère régularisé permettant la prise en compte explicite du bruit associé à l'expérimentation a ensuite été défini. Cette formulation ainsi que les équations issues des méthodes d'optimisation nécessaires à la minimisation du critère ont été parallélisées pour permettre une implantation sur GPU. Cet algorithme a ensuite été testé sur des cas de références issus de calcul numérique afin de vérifier si le champ reconstruit par l'algorithme était en accord avec celui fourni. Dans ce cadre, nous avons développé un outil permettant de simuler une BOS3D virtuelle afin d'obtenir les champs de déviation associés aux écoulements numériques. Ces champs de déviation ont ensuite été fournis comme entrée au code de reconstruction et nous ont permis d'étudier la sensibilité de notre algorithme à de nombreux paramètres tels que le bruit sur les données, la discrétisation du maillage, le type de régularisation et le positionnement des caméras. En parallèle de l'étude de la méthode de reconstruction par simulation, nous avons acquis de l'expérience sur la mise en œuvre effective de la mesure BOS dans des installations expérimentales, en participant à plusieurs campagnes d'essais. Cela nous a permis de contribuer à la conception et à la réalisation de bancs de mesures dédiés à la technique BOS. Le principal résultat de ce travail est la réalisation du banc de mesure BOS3D du DMAE, qui permet d'accéder à la reconstruction de champs de masse volumique instantanés. Ces développements expérimentaux nous autorisent finalement à obtenir des reconstructions 3D de champs de masse volumiques moyens et instantanés sur données réelles. De plus, l'analyse du comportement de la méthode numérique BOS3D est proposée en fonction de la nature des écoulements observés et de la configuration d'acquisition.

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Schülein, Christa Marion [Verfasser], Wilhelm [Akademischer Betreuer] Schwieger, Wilhelm [Gutachter] Schwieger, and Martin [Gutachter] Hartmann. "Trägergestützte SAPO-34 Zeolithmembranen: Ein Modellsystem zur Entwicklung verschiedener Methoden zum Schließen potentieller Defekte in Zeolithschichten / Christa Marion Schülein ; Gutachter: Wilhelm Schwieger, Martin Hartmann ; Betreuer: Wilhelm Schwieger." Erlangen : FAU University Press, 2020. http://d-nb.info/1220911178/34.

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Žemlová, Markéta. "Studium vlivu směsné ochranné atmosféry při laserovém svařování austenitických korozivzdorných ocelí." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2016. http://www.nusl.cz/ntk/nusl-241724.

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The diploma thesis deals with problems of laser welding in shielding gases. On the basis of theoretical knowledge in this thesis, was made welding an experiment of 10 samples of steel X5CrNi18-10 in two different shielding gases. Flow of shielding gases has been shown by schlieren method. On the samples of welding joints have been made mechanical tests (tensile test and hardness test). Welded joints were metallography evaluated and structure of them was confirmed by measurements on ferrite meter.

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Hofmann, Marcus. "Fallbasierte Speicherung und Wiederverwendung von Erfahrungswissen über die prozessbezogene Implementierung von Services in SAP® Enterprise-SOA." Doctoral thesis, Universitätsbibliothek Chemnitz, 2009. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-200901071.

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Der wirtschaftliche Erfolg von Unternehmen wird heute von der Fähigkeit beeinflusst, die Geschäftsstrategie schneller umsetzen zu können als die Konkurrenz. Wichtige Ziele sind die Erschließung neuer Märkte, die Reduzierung von Kosten sowie die Steigerung der Effizienz. Eine Voraussetzung besteht darin, vorhandene Geschäftsprozesse flexibel anpassen und zügig neue Prozesse einführen zu können. Das bedingt wandlungsfähige und innovationsfördernde Systemlandschaften. An dieser Stelle setzen die durch Geschäftsprozesse getriebenen serviceorientierten Architekturen für ERP-Systeme an. Mit SOA-ERP-Systemen wird es möglich, selektiv und am Bedarf ausgerichtet neue Prozesse zu gestalten und das Prozess-Design mit der Einbindung von Lieferanten, Kunden und Partnern über Unternehmensgrenzen hinweg zu gestalten. SAP Enterprise-SOA bezeichnet die serviceorientierte ERP-Architektur der SAP AG. Die darauf basierenden Anwendungen entstehen – unter Einsatz der Enterprise-SOA Roadmap-Methodik – durch die gezielte Kombination von Plattform-, Ex-tension- und Composite-Applikationen. Letztere stellen hochflexible, aus Enterprise-Services/Services von Drittanbietern erstellte, Anwendungen dar. Deren Design durch SOA-Experten liegt ein hohes Maß an Erfahrungswissen zu Grunde. Dieses stellt den zentralen Aspekt der Speicherung und Wiederverwendung durch fallbasiertes Schließen dar. Im Gegensatz zum bestehenden Ansatz zur Beschreibung von Best-Practice Implementierungen im „SAP Community Network“ ermöglicht der hier dargestellte Vorschlag die strukturierte, prozessbezogene Speicherung sowie die ähnlichkeitsbasierte Wiederverwendung von Composite-Applikationen innerhalb des Roadmap-Prozesses. Schwerpunktmäßig werden dazu Indizes zum Aufbau von Zugriffsstrukturen in der Fallbasis sowie wie ein allgemeingültiges globales und ein beispielhaftes, kontextspezifisches lokales Indexvokabular erarbeitet. Weiterhin erfolgt die Angabe entsprechender Ähnlichkeitsmaße für die ausgeprägten Indizes sowie das Aufzeigen der Ähnlichkeitsbestimmung zwischen zwei Fällen durch einen Nearest-Neighbor Matching Algorithmus.

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Clauß, Michael. "Methode zum Einsatz von Web 2.0-Werkzeugen in der Fabrikplanung." Doctoral thesis, Universitätsbibliothek Chemnitz, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-115479.

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Dem Web 2.0 werden - nicht selten mit euphorischem Unterton - hinsichtlich Interaktion, Selbstorganisation und Nutzbarmachung kollektiver Intelligenz enorme Nutzenpotentiale nachgesagt. Ansätze mit Bezug zum Unternehmenskontext werden unter dem Stichwort Enterprise 2.0 behandelt und beschäftigen sich vorrangig mit der Unterstützung des betrieblichen Wissensmanagements. Speziell für die zunehmend durch Komplexität sowie intensive Interaktionsprozesse geprägte Fabrikplanung lassen sich durch einen zielgerichteten Einsatz von Web 2.0-Werkzeugen positive Effekte erwarten. Zielstellung dieser Arbeit ist die Entwicklung einer Methode zum Einsatz von Web 2.0-Werkzeugen in der Fabrikplanung. Hierfür erfolgt zunächst eine Bestandsaufnahme relevanter Ansätze und Begriffe in diesen Bereichen. Anschließend wird auf Grundlage system-, handlungs- und tätigkeitstheoretischer Überlegungen ein situativer Forschungsansatz begründet. Die Methodenentwicklung erfolgt als problemspezifische Ausgestaltung des Fall-basierten Schließens. Sie ist in ein entsprechend angepasstes Vorgehen der morphologisch-typologischen Theorieentwicklung eingebettet und basiert auf einer umfassenden Analyse hierfür relevanter Theorien, Modelle und Ansätze. Die Methode beruht auf einer kontinuierlichen Erfassung und Wiederverwendung von Erfahrungswissen. Sie wird abschließend evaluiert, wobei u.a. ein Prototyp entwickelt wird, der den praktischen Einsatz der entwickelten Methode unterstützt
The Web 2.0 is supposed to have huge potential for the support of interaction, selforganization and the utilization of collective intelligence. Approaches related to an enterprise context are discussed with the keyword Enterprise 2.0 and mainly deal with potentials to support the operational knowledge management. A systematic approach for the use of web-based collaborative tools is expected to generate positive effects on modern factory planning, which faces increasing complexity and dynamic interactions. The objective of this work is to develop a methodical approach for the use of web-based collaborative tools in factory planning. Therefore, in the first part of this thesis an overview of relevant approaches and terms in the areas of Web 2.0 and factory planning is being worked out. In a second step, a situational approach is identified as an appropriate view after due consideration and contextual discussion of system, action and activity theory. The development of the methodical approach is based on a problem-specific adaptation of case-based reasoning. It is embedded into an elaborated procedure of morphologic-typological theory building and bases on a comprehensive analysis of relevant theories, models and approaches. The evolved method relies on continuous collection and reutilisation of experiential knowledge. It is evaluated through different methods, inter alia by the construction of a prototype that supports its practical use

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Bigger, Rory P. Settles G. S. "Chemical vapor plume detection using the Schlieren optical method." 2008. http://etda.libraries.psu.edu/theses/approved/WorldWideIndex/ETD-3066/index.html.

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Chen, Xin-Yu, and 陳信宇. "Study on the Quantification Method of Schlieren Images for Temperature Measurements." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/26084141639043702388.

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碩士
國立高雄第一科技大學
營建工程研究所
103
The summer season in Taiwan is scorching hot, people feel sultry and uncomfortable. Therefor people need to close the windows and doors, completely dependent on the air conditioners to prevent heat stroke and reduce temperature. Unless the window and door are fully close, the indoor air still have convection with the outside air by the crack between door and the frame, causing air leakage and unnecessary energy consumption. Moreover, the most main reason of forming convection are the different density, temperature and pressure between inside and outside. In generally, in order to acquire the data from building openings, have to placed many instruments or measuring point around the opening to measure, however, more or less, these steps have affected the situation of air convection at that time. First, this study investigated about Quantification Method of Schlieren Image, if this technology could be used fully, not only can effectively observe the convection of air, also can get other useful information. Moreover, analysis schlieren imaging and provide an effective quantify method to do the actual quantify test and verify the air temperature, and to reach the feasibility of quantify of temperature. In this study, using Quantification Method of Schlieren Images to observe the three different temperature fields of Schlieren image among hot plate, cold plate and model house. After the direction of shooting light act is influenced by the air density gradient at the experimental area, there are display the chiaroscuro and show the different Schlieren imaging of any temperature. When shooting Schlieren imaging, place the thermocouple wire on the disk to measure the temperature values directly to be the basis comparison of schlieren quantified temperature field at the same time. The schlieren technique results show that: at 25 °C environment, air temperature field near the 100 °C hot plate surface, the amount of measurement error range is between –6.9 °C to 16.3°C; at the temperature field of 0 °C cold plate surface, the amount of measurement error range is between –3.7 °C to 2.2 °C; final, measure the opening parts that the temperature field of the model house which interior temperature is 16 °C to 20 °C, the amount of measurement error range is between –11 °C to –5 °C, besides, when the obscuring ratio is 60%, the error range is between –6.8 °C to 0.9 °C, the obscuring ratio is 70%, the error range is between –11.8 °C to –1.7 °C. This research use Quantification Method of Schlieren Images to observe different variation on different temperature field and provide visualization. Not only have the successful observation in quantizing schlieren imaging into temperature field, also could clearly see the air convection of the opening position. Moreover, for the situation that temperature difference varies small, also could adjust the chiaroscuro of schlieren image to display the clearly image.

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LIN, YING-YI, and 林英沂. "Investigate on the mechanism of soot forming in bio-oil by Schlieren method." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/28pbxa.

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碩士
國立虎尾科技大學
動力機械工程系機械與機電工程碩士班
106
In this study, the Schlieren method was used to investigate the mechanism of soot formation of Bio-oil. The characteristics of liquid fuel influence the characteristics of spray combustion or droplet combustion. These characteristics include: Component, saturated vapor pressure, boiling point, flash point and viscosity coefficient, etc. The viscosity of the fuel affects the quality of the spray and the characteristics of liquid fuel’s components affect the characteristics of fuel evaporation, flash ignition and combustion transfer. When the use of raw energy instead of fossil fuels become an important issue. The pyrolytic Bio-oil of the raw material is produced by the thermal decomposition of cellulose raw materials, but the components of the Bio-oil are quite complex. It is related to the source of its material and the parameters of the pyrolysis program. And there are many problems in use, including soot, coking, corrosion, etc. In GC-MS, TGA and FT-IR results show that the pyrolysis Bio-oil is mainly composed of polycyclic compounds, including: alkanes, aromatic hydrocarbons, phenols and aldehydes, etc. These components are precursor for soot formation and the boiling point of the volatiles of the bio-oil component during the combustion process, the difference in flash point (mainly polycyclic compounds such as aromatic hydrocarbons, alkanes, phenols and aldehydes) and the formation of particles, Different stages of droplet burning rate are formed. The direct image observation of the droplet combustion, When the Bio-oil droplets burned, droplet flame surround the entire droplet and the combustion process occurs once and twice micro-explosion. Under the normal gravity, it is affected by buoyancy and natural convection, so that the soot which surrounding the combustion droplet are blown away and during droplet combustion, is not easily observed by the visible image. So using the synchronous tech with dual-high camera and schlieren method can clearly observe the droplet combustion, and with the change in density under the flow field and diffusion during the droplet combustion. The result show that soot are formed in the shape of a chimney (called soot tail) and are distributed inside the visible flame, while the hot gas boundary is located outside the visible flame. The stagnation plane called Stefan flow which formed by the chemical interaction between the fuel and the oxidant and the reaction is surrounded by the lower circle of the combustion droplet. In the other hand, the soot tail affects the heat transfer from the flame to the droplet surface and the soot with it radiates to promote heat exchange, which shows the temperature tends to be unstable and the slope increases significantly of surface boiling point from the fast pyrolysis droplets. As the combustion process evolves, more weaker carbon bond components participate into the reaction, which influenced by the composition and the soot tail. And the significant soot formation effect the Grashof number with different stages of the density change.

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(10757814), Angel David Lozano Galarza. "EXPERIMENTAL STUDIES ON FREE JET OF MATCH ROCKETS AND UNSTEADY FLOW OF HOUSEFLIES." Thesis, 2021.

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The aerodynamics of insect flight is not well understood despite it has been extensively investigated with various techniques and methods. Its complexities mainly have two folds: complex flow behavior and intricate wing morphology. The complex flow behavior in insect flight are resulted from flow unsteadiness and three-dimensional effects. However, most of the experimental studies on insect flight were performed with 2D flow measurement techniques whereas the 3D flow measurement techniques are still under developing. Even with the most advanced 3D flow measurement techniques, it is still impossible to measure the flow field closed to the wings and body. On the other hand, the intricate wing morphology complicates the experimental studies with mechanical flapping wings and make mechanical models difficult to mimic the flapping wing motion of insects. Therefore, to understand the authentic flow phenomena and associated aerodynamics of insect flight, it is inevitable to study the actual flying insects.

In this thesis, a recently introduced technique of schlieren photography is first tested on free jet of match rockets with a physics based optical flow method to explore its potential of flow quantification of unsteady flow. Then the schlieren photography and optical flow method are adapted to tethered and feely flying houseflies to investigate the complex wake flow and structures. In the end, a particle tracking velocimetry system: Shake the Box system, is utilized to resolve the complex wake flow on a tethered house fly and to acquire some preliminary 3D flow field data

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Hofmann, Marcus. "Fallbasierte Speicherung und Wiederverwendung von Erfahrungswissen über die prozessbezogene Implementierung von Services in SAP® Enterprise-SOA." Doctoral thesis, 2008. https://monarch.qucosa.de/id/qucosa%3A19155.

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Der wirtschaftliche Erfolg von Unternehmen wird heute von der Fähigkeit beeinflusst, die Geschäftsstrategie schneller umsetzen zu können als die Konkurrenz. Wichtige Ziele sind die Erschließung neuer Märkte, die Reduzierung von Kosten sowie die Steigerung der Effizienz. Eine Voraussetzung besteht darin, vorhandene Geschäftsprozesse flexibel anpassen und zügig neue Prozesse einführen zu können. Das bedingt wandlungsfähige und innovationsfördernde Systemlandschaften. An dieser Stelle setzen die durch Geschäftsprozesse getriebenen serviceorientierten Architekturen für ERP-Systeme an. Mit SOA-ERP-Systemen wird es möglich, selektiv und am Bedarf ausgerichtet neue Prozesse zu gestalten und das Prozess-Design mit der Einbindung von Lieferanten, Kunden und Partnern über Unternehmensgrenzen hinweg zu gestalten. SAP Enterprise-SOA bezeichnet die serviceorientierte ERP-Architektur der SAP AG. Die darauf basierenden Anwendungen entstehen – unter Einsatz der Enterprise-SOA Roadmap-Methodik – durch die gezielte Kombination von Plattform-, Ex-tension- und Composite-Applikationen. Letztere stellen hochflexible, aus Enterprise-Services/Services von Drittanbietern erstellte, Anwendungen dar. Deren Design durch SOA-Experten liegt ein hohes Maß an Erfahrungswissen zu Grunde. Dieses stellt den zentralen Aspekt der Speicherung und Wiederverwendung durch fallbasiertes Schließen dar. Im Gegensatz zum bestehenden Ansatz zur Beschreibung von Best-Practice Implementierungen im „SAP Community Network“ ermöglicht der hier dargestellte Vorschlag die strukturierte, prozessbezogene Speicherung sowie die ähnlichkeitsbasierte Wiederverwendung von Composite-Applikationen innerhalb des Roadmap-Prozesses. Schwerpunktmäßig werden dazu Indizes zum Aufbau von Zugriffsstrukturen in der Fallbasis sowie wie ein allgemeingültiges globales und ein beispielhaftes, kontextspezifisches lokales Indexvokabular erarbeitet. Weiterhin erfolgt die Angabe entsprechender Ähnlichkeitsmaße für die ausgeprägten Indizes sowie das Aufzeigen der Ähnlichkeitsbestimmung zwischen zwei Fällen durch einen Nearest-Neighbor Matching Algorithmus.

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Dissertations / Theses on the topic 'Schlieren method'

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