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Advanced turbulence simulation for aerodynamic application challenges (ATAAC)

Das Projekt "Advanced turbulence simulation for aerodynamic application challenges (ATAAC)" wird vom Umweltbundesamt gefördert und von Deutsches Zentrum für Luft- und Raumfahrt e.V. durchgeführt. The ATAAC project aims at improvements to Computational Fluid Dynamics (CFD) methods for aerodynamic flows used in today's aeronautical industry. The accuracy of these is limited by insufficient capabilities of the turbulence modelling / simulation approaches available, especially at the high Reynolds numbers typical of real-life flows. As LES will not be affordable for such flows in the next 4 decades, ATAAC focuses on approaches below the LES level, namely Differential Reynolds Stress Models (DRSM), advanced Unsteady RANS models (URANS), including Scale-Adaptive Simulation (SAS), Wall-Modelled LES, and different hybrid RANS-LES coupling schemes, including the latest versions of DES and Embedded LES. The resources of the project will be concentrated exclusively on flows for which the current models fail to provide sufficient accuracy, e.g. in stalled flows, high lift applications, swirling flows (delta wings, trailing vortices), buffet etc. The assessment and improvement process will follow thoroughly conceived roadmaps linking practical goals with corresponding industrial application challenges and with modelling/simulation issues through stepping stones represented by appropriate generic test cases. The final goals of ATAAC are: - to recommend one or at most two best DRSM for conventional RANS and URANS- to provide a small set of hybrid RANS-LES and SAS methods that can be used as reference turbulence-resolving approaches in future CFD design tools - to formulate clear indications of areas of applicability and uncertainty of the proposed approaches for aerodynamic applications in industrial CFD - Contributing to reliable industrial CFD tools, ATAAC will have a direct impact on the predictive capabilities in design and optimisation, and directly contribute to the development of Greener Aircraft.

Prototypical policy impacts on multifunctional activities in rural municipalities (PRIMA)

Das Projekt "Prototypical policy impacts on multifunctional activities in rural municipalities (PRIMA)" wird vom Umweltbundesamt gefördert und von Centre National du Machinisme Agricole, du Génie Rural, des Eaux et des Forêts durchgeführt. Objective: The proposed project will develop a method for scaling down the analysis of policy impacts on multifunctional land uses and on the economic activities. This method will rely on micro-simulation and multi-agents models, designed and validated at municipality level using input from stakeholders. The models will address the structural evolution of the populations (appearance, disappearance and change of agents) depending on the local conditions for applying the structural policies on a set of municipality case studies. We shall consider policies related to use of Structural Funds (SFs), Cohesion Fund (CF), Preaccession funds (PAFs) and EAFRD (respectively CAP). This project will include the following actions: - Review the EU structural policies, identify driving forces at EU, national and regional levels for multifunctional land use activities and provide baselines for the design of national and regional scenarios on multifunctional land use activities. - Interaction with stakeholders: pre-model engagement with stakeholders in terms of scenario design and formulating agent decision rules for agent-based models, on-model engagement with stakeholders mirroring agent-based models, and post-model engagement with stakeholders in terms of assessing model outputs. - Design and develop micro-simulation and multi-agents models, of local dynamics and of the impact of European structural policies at the municipality level. - Build a mapping between available data on municipalities and prototypical, contrasted evolutions of micro-simulation and agent based models. This will allow us to aggregate the results provided by these models at a regional level, on a set of regional case studies, and to compare these results with existing models at regional scale. - Investigate the potential of the approach to design a method that enhances the scope of Strategic Environmental Assessment (SEA), Environmental Impact Assessment (EIA) and Sustainable Impact Assessment (SIA). Prime Contractor: Centre National du Machinisme Agricole, du Génie Rural, des Eaux et des Forets; Antony; France.

CCES-TRAMM: Triggering of Rapid Mass Movements in Steep Terrain

Das Projekt "CCES-TRAMM: Triggering of Rapid Mass Movements in Steep Terrain" wird vom Umweltbundesamt gefördert und von Eidgenössische Forschungsanstalt für Wald, Schnee und Landschaft durchgeführt. The primary goal of this poly-project is to improve quantification and predictability of hazardous mass movements including landslides, snow avalanches, and debris flows. The project includes experts from 9 different institutes at EPF Lausanne, ETH Zürich and WSL. We plan laboratory and field experiments, spatial analyses of hill-slope failures, development of new modeling approaches and new measurement methodology. These will be integrated in a common platform for modeling and hazard assessment as well serving certain training and educational purposes related to hill-slope hazards. The different experimental and modeling activities will be conducted in close collaboration between the institutes with open access to data and results for all participants. Within TRAMM the Research Unit Mountain Hydrology and Torrents focus on two particular aspects related to shallow landslides: a) The two-dimensional simulation of water fluxes along a hillslope that is potentially susceptible to failure. We use the model HillVi (Weiler, Univ. of British Columbia) for that purpose. The focus will be on the statistical distribution of water saturation across the investigated slope. b) The quantification of mechanical effects of roots on slope stability. Within this scope we compare different methods for the monitoring and the description of rooted soils. The distribution of the obtained local rooted-soil strength would be abstracted to generate a map of bonds , finally coupled with other important parameters in a SOC-like approach (self-organised criticality).

Climate change and ice cap history on Kilimanjaro: Application of direct field measurements and large-scale gridded data to a physical mass balance model (CCIK)

Das Projekt "Climate change and ice cap history on Kilimanjaro: Application of direct field measurements and large-scale gridded data to a physical mass balance model (CCIK)" wird vom Umweltbundesamt gefördert und von Universität Innsbruck, Institut für Geographie durchgeführt. Glaciers around the world have retreated over the 20th century, which is also true of tropical glaciers. Although the characteristics of tropical glaciers (a high sensitivity to moisture-related climate variables) also apply to the glaciers on Kilimanjaro (Equatorial East Africa), studying their behavior requires a special view. This is because different glacier systems exist on Kilimanjaro: tabular-shaped ice bodies on the summit plateau, and slope glaciers below the summit plateau on the mountains steep flanks. The plateau glaciers are margined by vertical ice cliffs that - once they are established - lead to an irreversible areal recession of the plateau glaciers, regardless of the mass balance on the plateau glaciers horizontal surface. A preceding project could demonstrate that the main climatic reason of the current glacier retreat on Kilimanjaro (which commenced around 1880) is a regionally drier climate since the late 19th century, and that the glaciers show a much higher sensitivity to precipitation fluctuations than to air temperature changes. It also became clear that current climate pushes the glaciers close to disappearance, which raises the question under which climate conditions those glaciers could form and exist at all. The present project therefore aims at reconstructing at least 500 years of glacier history on Kilimanjaro and climate change in the tropics, to identify potential phases of an ice-free summit of Africas highest mountain. Since other precipitation-sensitive proxies (particularly lake levels) indicate greater climate fluctuations before 1880 than afterwards, it is likely that glacier existence on Kilimanjaro summit follows a relatively short-term cycle. On-site meteorological measurements with automatic weather stations will continue in the proposed project, in order to run.

Investigation on Physicochemical Proceses Leading to Acid Production in Radiation Fog and Captive Clouds

Das Projekt "Investigation on Physicochemical Proceses Leading to Acid Production in Radiation Fog and Captive Clouds" wird vom Umweltbundesamt gefördert und von Universität Frankfurt, Zentrum für Umweltforschung durchgeführt. Objective: To provide information on the conversion rate of sulphur and nitrogen oxides in the liquid phase. General information: the research projects complements, by means of field experiments, the already performed laboratory studies on the aqueous phase conversion of SO2 and NOx to H2SO4 and HNO3. The two laboratories involved, Universitaet Frankfurt and CNR bologna, proposal 27, consider three different environmental and climatic situations: - radiation fog in a rural area (Po valley, Italy) - radiation fog in an industrialised region (Main valley, FRG) - captive clouds in an industrialised region (kleiner Feldberg, FRG). The formation of sulphate and nitrate in droplets is investigated during these experiments. Achievements: An investigation was made of the interactions of cloud and fog droplets with atmospheric pollutants. It is now recognized that cloud water can contain high levels of acidity. The 2 different types of clouds investigated were ground fogs and captive frontal clouds. Results from fog experiments support the idea of possible none quilibrium conditions between gas and liquid phase in polluted fogs, caused by the presence of surface active substances on the surface of the droplets. If this effect is real, it will have to be taken into account in models describing cloud/fog evolution and chemistry. A sampling station has been designed and built in the Po Valley, Italy for automatic collection of samples during fog events. The automatic station has the capability to sample large numbers of fog events with a good reproducibility. The station comprises a fog detector, sampling unit and computer controller. The sampling station was operated continuously from the beginning of November 1989 to the end of April 1990. During this period fog statistics, fog water chemical composition and deposition were investigated. Fog occurrence accounted for 23 per cent of the total time. The total ionic strength of fog water was mostly accounted for by ammonium, nitrate and sulphate ions observed from November to March. The notable increase of sulphate concentration over the period can be attributed to efficient sulphur dioxide to sulphate ion conversion due to an increased availability of oxidants. The data obtained so far with this automatic station gives information on the seasonal budget of chemical deposition due to fog in the Po Valley.

Unterscheidung Gleichgewicht / Nichtgleichgewicht in Saeulenversuchen zur Elution organischer Schadstoffe: Materialuntersuchungen und Modellentwicklung.

Das Projekt "Unterscheidung Gleichgewicht / Nichtgleichgewicht in Saeulenversuchen zur Elution organischer Schadstoffe: Materialuntersuchungen und Modellentwicklung." wird vom Umweltbundesamt gefördert und von Universität Tübingen, Institut und Museum für Geologie und Paläontologie durchgeführt. Ziel dieses Vorhabens ist es eine auf Material- und Schadstoffeigenschaften basierende Methode zu entwickeln, die es dem Analytiker im Labor ermoeglicht, die zeitliche Entwicklung der Schadstoffkonzentrationen im Saeuleneluat apriori vorherzusagen (wie lange erfolgt die Elution unter Gleichgewicht - ab wann ist mit Ungleichgewicht zu rechnen). Zusaetzlich sollen die heute bereits vorliegenden Erkenntnisse zur Schadstoffelution durch Saeulenversuche mit Materialien, ueber deren Schadstoff-Freisetzungverhalten bislang keine ausreichenden Kenntnisse vorliegen, ergaenzt werden. Dies sind insbesondere kohlehaltige Boeden (z.B. aus dem Ruhrgebiet). Schlacken, Aschen und Sedimente (z.B. Baggergut aus Hafenbecken). Die erhobenen Material- und Schadstoffkonstanten sollen in einer Datensammlung zusammengefuehrt werden, anhand derer das Elutionsverhalten abgeschaetzt werden kann. Der hier beschriebene Ansatz kann in einer 2. Projektphase auch auf wasserundurchlaessige groessere Einzelkoerper uebertragen werden.

Makroökonomie und -ökonometrie

Das Projekt "Makroökonomie und -ökonometrie" wird vom Umweltbundesamt gefördert und von Leibniz Zentrum für Europäische Wirtschaftsforschung GmbH, Forschungsbereich Umwelt- und Ressourcenökonomik, Umweltmanagement durchgeführt. Die temporäre Arbeitsgruppe 'Makroökonomie und -ökonometrie' konstituierte sich, um die am ZEW angewandten makroökonomischen und -ökonometrischen Modelle untereinander zu vergleichen und um zu überprüfen, ob bei einer Simulationsstudie die einzelnen Modelle zu einem tendenziell gleichen Ergebnis gelangen. Für die Simulation wurde unterstellt, dass die Sozialbeiträge um vier Prozentpunkte gesenkt werden, wobei für das erste Jahr der Absenkung eine Gegenfinanzierung in gleicher Größenordnung durch eine Erhöhung der Mehrwertsteuer unterstellt wurde. Alternativ wurde eine Erhöhung der indirekten Steuern unterstellt. Modelle, die entweder nur das Unternehmen oder nur den Arbeitnehmer abbilden, wurden mit einer entsprechend geringen Beitragssenkung simuliert. Ist modellmäßig keine Gegenfinanzierung erfassbar, dann wird einzig der Effekt der verringerten Beitragssätze untersucht. Gegenstand der Überprüfung waren das Konstanzer makroökonomische Ungleichgewichtsmodell, das allgemeine Gleichgewichtsmodell GEM-E3 aus dem Bereich Umwelt- und Ressourcenökonomik, Umweltmanagement, ein hochaggregiertes Modell des Arbeitsmarktes, ein internationales Intergenerationenmodell zur Erfassung der Rentenentwicklung und der European Tax Analyzer. Die Ergebnisse dieser Studie erschienen als ZEW Discussion Paper. In einem weiteren Schritt wurden Vorschläge unterbreitet, wie einerseits die vorhandenen Modelle gepflegt und weiterentwickelt und welche forschungsbereichsübergreifenden makroökonomischen Fragestellungen mit Hilfe der Modelle aufgegriffen werden sollten. In Zukunft werden makroökonomische Forschungsschwerpunkte verstärkt auf eine gesamteuropäische Sichtweise ausgerichtet. Hierzu dienen die Modelle als Grundlage für empirische Studien über wirtschaftspolitische Maßnahmen.

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