Das Projekt "Teilvorhaben: 2.2a, 3.4 und 3.5" wird vom Umweltbundesamt gefördert und von Siemens Gas und Power GmbH & Co. KG durchgeführt. Das Vorhaben unterstützt wesentlich die Auslegungs- und Optimierungsprozesse für optimale Effizienz und Lebensdauer von Turbinenkomponenten an unterschiedlichsten Betriebspunkten. Im aktuellen Vorhaben werden neue Konzepte und Module zur multidisziplinaren Optimierung erarbeitet. Bei zukünftigen hocheffizienten Gasturbinen, die einen hochflexiblen Betrieb in einem sehr großen Betriebsbereich gewährleisten können, bekommen aeromechanische Schwingungsanregungen eine viel größere Bedeutung. Für Turbinenschaufeln sind sie Design-beeinflussend und können nicht mehr durch Design vollständig vermieden werden. Daher wird eine gezielte Dämpfungsoptimierung notwendig, die mit dem Schaufeldesign durchgeführt werden muss und nur noch durch eine multidisziplinäre Optimierung erreicht werden kann. Bei der Fertigung sowie dem Betrieb von Gasturbinen werden heute immer größere Datenmengen erzeugt. Ziel ist es, ein datenbasiertes Modell für Varianzen aus dem Fertigungsprozess und für den Betrieb von Turbinenkomponenten zu entwickeln. Dazu werden geeignete Modelle erstellt, welche in der Lage sind, die möglichen Abweichungen aus der vorhandene Datenbasis auf neue Bauteile zu übertragen. Mit Hilfe dieser Modelle werden dann realistische Geometrievariationen und Randwertschwankungen erzeugt, welche dann die Basis für eine probabilistische Lebensdauer- und Performancequantifizierung neuer Komponenten bildet. Ein möglichst großer Wirkungsgrad wird maßgeblich durch den Verbrauch von Kühlluft bestimmt. Zur Steigerung des Wirkungsgrades muss daher der Verbrauch von Kühlluft minimiert werden. Als Verbesserung gegenüber semiempirischen, korrelationsbasierten Berechnungsmethoden stehen bereits sogenannte Konjugierte Simulationsmethoden (Conjugate Heat Transfer) zur Verfügung, welche Strömungsfluid und Bauteil gekoppelt modellieren. Die industrielle Anwendung dieser Methoden soll durch Validierung und Automatisierung möglich gemacht werden.
Das Projekt "Energy Storage for Direct Steam Solar Power Plants (DISTOR)" wird vom Umweltbundesamt gefördert und von Deutsches Zentrum für Luft- und Raumfahrt e.V., Institut für Technische Thermodynamik durchgeführt. Objective: Solar thermal power plants represent today's most economic systems to generate electricity from solar insulation in them-range in regions like the Mediterranean area. By demonstrating the feasibility of direct steam generation in the absorber pipes European industry and research institutions have gained a leading position in this technology area. A key element foray successful market penetration is the availability of storage systems to reduce the dependence on the course of solarinsolation. The most important benefits result from -reduced internal costs due to increased efficiency and extended utilisation of the power block-facilitating the integration of a solar power plant into an electrical grid-adoption of electricity production to the demand thus increasing revenues Efficient storage systems for steam power plants demand transfer of energy during the charging/discharging process at constant temperatures. The DISTOR project focuses on the development of systems using phase change materials (PCM) as storage media. In order to accelerate the development, the DISTOR project is based on parallel research on three different storage concepts. These concepts include innovative aspects like encapsulated PCM, evaporation heat transfer and new design concepts. This parallel approach takes advantage of synergy effects and will enable the identification of the most promising storage concept. A consortium covering the various aspects of design and manufacturing has been formed from manufacturers, engineering companies and research institutions experienced in solar thermal power plants and PCM technology. The project will provide advanced storage material based on PCM for the temperature range of 200-300 C adapted to the needs of Direct Steam generation thus expanding Europe's strong position in solar thermal power plants.
Das Projekt "Pasture rehabilitation on, and management of degraded areas in the Andes of South Ecuador" wird vom Umweltbundesamt gefördert und von Universität Bayreuth, Fachgruppe Biologie, Bayreuther Zentrum für Ökologie und Umweltforschung (BayCEER), Lehrstuhl für Pflanzenphysiologie durchgeführt. Project abstract: This knowledge transfer project will be centered in the San Francisco valley in the South Ecuadorian Andes. However, the problem of abandoning pastures because of heavy infestation by weeds, in particular by bracken fern (Pteridium spec.), is a general issue in the tropical Andes. Pastures which have been abandoned for that reason amount meanwhile to 11Prozent of the area of the San Francisco valley. Infestation by bracken fern and shrubs is a consequence of the traditional use of fire for clearing of the natural forest and pasture management. Growth of both, bracken and woody weeds, is fostered by recurrent burning. In a 2-phase experiment on a heavily bracken-infested slope at c. 2000 m altitude, substantial control of the weed and subsequent pasture rehabilitation could be achieved. In the planned project, this procedure shall be scaled-up to farm level and the altitudinal range of repasturisation shall be extended from 1000 m to 2400 m altitude. To that end local farmers will put respective parts of their land to the projects disposal and public authorities will provide man-power. There are several challenges to be met: (i) Long-term bracken infestation has depleted the soils from nutrients, in particular P and N. Therefore targeted fertilization is needed for profitable grass productivity. (ii) Since bracken can never be completely eradicated, its regrowth must be suppressed by trampling, i.e. frequent grazing. A sustainable grazing management has to be developed which corresponds to soil fertility. (iii) The dominating pasture grass is the C4-type grass Setaria sphacelata. It is growing well in a warm climate but its competitive strength in the harsher climate above 2000 m is low. Bracken as a C3-type plant is less dependent on the temperature. To this adds that it occurs in 2 species in the area, one of which is an upland type. Thus the climate gradient over the elevational transect will influence the competitive strength of both competitors. Therefore the suitability of the traditional monoculture of this grass species for pasture rehabilitation shall be tested in the context of a comprehensive pasture management experiment which the farmers will be involved. (iv) A special problem is the high oxalate concentration in the growing parts of the Setaria leaves which can cause calcaemia in cattle. In a pot experiment which will be run in collaboration with a research team of the UTPL, feeding quality and toxicity of a monotonous diet of Setaria will be tested. Beside the experimental areas, demonstration sites will be installed where regular training workshops will be organized to encourage the farmers to apply the developed rehabilitation and management strategy to their own farms.
Das Projekt "Biopores in the subsoil: Formation, nutrient turnover and effects on crops with distinct rooting systems (BioFoNT)" wird vom Umweltbundesamt gefördert und von Universität Bonn, Institut für Organischen Landbau durchgeführt. Perennial fodder cropping potentially increases subsoil biopore density by formation of extensive root systems and temporary soil rest. We will quantify root length density, earthworm abundance and biopore size classes after Medicago sativa, Cichorium intybus and Festuca arundinacea grown for 1, 2 and 3 years respectively in the applied research unit's Central Field Trial (CeFiT) which is established and maintained by our working group. Shoot parameters including transpiration, gas exchange and chlorophyll fluorescence will frequently be recorded. Precrop effects on oilseed rape and cereals will be quantified with regard to crop yield, nutrient transfer and H2-release. The soil associated with biopores (i.e. the driloshpere) is generally rich in nutrients as compared to the bulk soil and is therefore supposed to be a potential hot spot for nutrient acquisition. However, contact areas between roots and the pore wall have been reported to be low. It is still unclear to which extent the nutrients present in the drilosphere are used and which potential relevance subsoil biopores may have for the nutrient supply of crops. We will use a flexible videoscope to determine the root-soil contact in biopores. Nitrogen input into the drilosphere by earthworms and potential re-uptake of nitrogen from the drilosphere by subsequent crops with different rooting systems (oilseed rape vs. cereals) will be quantified using 15N as a tracer.
Das Projekt "SP 2.1 Design, modeling and evaluation of improved cropping strategies and multi-level interactions in mixed cropping systems in the North China Plain" wird vom Umweltbundesamt gefördert und von Universität Hohenheim, Institut für Kulturpflanzenwissenschaften (340), Fachgebiet Allgemeiner Pflanzenbau (340a) durchgeführt. In China, the productivity of arable land needs to be further increased. However, with N-fertilizer rates being extremely high already and due to a shortage of irrigation water, further yield increases are not possible by increasing the amount of these input factors. Strategies to reduce or avoid negative environmental effects including water saving while maintaining high yields have to be developed. Yield increases, may be possible by appropriately adjusting cropping systems, either by design (e.g. intercropping as a mixed cropping system), crop sequence and rotation, or improved input factor efficiency. The main objective of this subproject will be to design, model and evaluate improved cropping strategies and multi-level interactions in mixed cropping systems. Based on a process-oriented modeling approach, the project will emphasize on the evaluation of cropping system prototypes including different crops (spring maize, summer maize, wheat, peanut), different designs (intercropping, mixed cropping), different crop sequences and rotations (e.g. spring maize monoculture versus double cropping winter wheat-summer maize) and different input factor levels of water and nitrogen for different regions and agro-climatic conditions in the North China Plain. By doing so, the project aims at exploring the possibilities and at creating new methodologies for improving the cropping systems in the North China Plain. Within the modeling approach competitive relationships between crop species regarding yield, solar radiation, water and nitrogen will be analyzed and modeled. The project will design the necessary methods and basic approaches for the description of the relevant indicator parameters and transfer these into a thorough modeling approach.
Das Projekt "Sub project:The effect of iron(III)-sulfide interactions on electron transfer processes in anoxic aquifers" wird vom Umweltbundesamt gefördert und von Universität Bayreuth, Fachgruppe Geowissenschaften, Bayreuther Zentrum für Ökologie und Umweltforschung (BayCEER), Lehrstuhl für Hydrologie durchgeführt. Strong evidence exists that the oxidation of H2S by ferric (oxyhydr)oxides occurs also in ground water systems and may exert a major role for the sulphur and iron cycle and in particular for the electron and carbon flow in aquifers. To date, no systematic study has been performed that allows to quantitatively assess its significance in such systems. This project aims to fill this gap of knowledge. The extent of the reaction depends on mineral reactivity, which we hypothesize can be expressed in terms of a generalized kinetic model for the full pH range of environmental relvance. This model accounts for the adsorption of H2S at lower pH values and of HS- at circumneutral pH to the neutral ferric (oxyhydr)oxide surface to form the reactive species FeSH. Variations in reactivity may be caused by intrinsic factors such as surface acidity of the iron mineral and solution composition, such as ionic strength and competition with other ions. The overall goals of this project therefore are to demonstrate the validity of this approach in order to quantify the kinetics for abiotic anaerobic H2S oxidation by ferric (oxyhydr)oxides, and to elucidate the role of this process as a precursor reaction for further microbial transformation of sulphur species in the aquifer.
Das Projekt "Main Annulus Gas Path Interactions (MAGPI)" wird vom Umweltbundesamt gefördert und von Rolls-Royce Deutschland Ltd & Co KG durchgeführt. In a modern aero engine, up to 20Prozent of the main annulus flow is bled off to perform cooling and sealing functions. The vicinity of these bleed ports and flow sinks is characterised by complex unsteady swirling flows, which are not fully understood. Even the most up-to-date numerical tools have difficulties predicting the behaviour of the secondary flow system when interacting with the main annulus. The project addresses interactions between main gas path and secondary flow systems in commercial gas turbines in response to Research Activity AERO-2005-1.3.1.2a Concepts and technologies for improving engine thermal efficiency and reducing secondary air losses. Experiments are planned on turbine disc rim and compressor manifold cavity heat transfer, hot gas ingestion, and spoiling effects of cooling air flow and their impact on turbine and compressor performance, as well as a reduction of secondary air losses. The experimental data will be used for better understanding of the complex flow phenomena and improvements of platform and cavity design. Furthermore, the industrial partners will validate their design tools with these test data and improve their prediction capability of secondary flow systems when interacting with the main gas path. The expected results are a reduction of cooling and sealing airflow rates, improvements of the turbine and compressor efficiency and increase of the safety margin of the engine components by better cooling. Expected technical results are: - Knowledge of the interaction phenomena and its effect on cavity heat transfer, spoiling and performance, - Experimental results for validation of improved numerical tools for secondary flow systems, - Optimised design methods and CFD best practice guidelines. The targeted outcome will contribute to the ACARE goal of reduced CO2 emissions via reduced fuel burn of 2Prozent to improve the environment and strengthening the competitiveness of European gas turbine manufacturers.
Das Projekt "Water consumption and carbon capture by trees of an evergreen and a dry forest in the Andes of South Ecuador as functional indicators of slow environmental changes" wird vom Umweltbundesamt gefördert und von Universität Bayreuth, Fachgruppe Biologie, Bayreuther Zentrum für Ökologie und Umweltforschung (BayCEER), Lehrstuhl für Pflanzenphysiologie durchgeführt. This transfer project contributes to the development of a multifactorial indicator prototype for global change effects. It uses water and carbon relations of trees as primary functional indicators of subtle environmental changes which cannot be directly observed. Acquisition of carbon by a tree and its concomitant water loss by transpiration is coupled as water use efficiency (WUE), which as a parameter integrating two ecophysiological processes should display a high sensitivity to ambiental conditions. The project is based on a new model allowing computation of the entire crown. Parameterization of the model is by data of leaf gas exchange, total water loss, and structural data of the crown. Total water consumption will be determined either by stem flow monitoring or by the D2O injection method. Net carbon gain by the entire crown can be calculated from a crown-specific WUE. The described measurements will be supplemented by data on stem growth, phenology (longevity of leaves and foliage dynamics), long-term water relations (13C discrimination data) and tree hydrology (natural abundance of deuterium). To extend the indicator from the single tree scale to a wider area, project C5 will collaborate with project C6 which will investigate WUE using multispectral satellite and airborne data. For calibration transfer functions to remotely sensed data must be developed. Since Eddie covariance analysis cannot be used, project C6 will measure atmospheric dynamics of heat and water vapour above the canopy of an assemblage of such trees by scintillometry. These measurements shall be calibrated by C5. Of all trees on the study plots total transpiration will be measured and correlated with simultaneously recorded scintillometer data. Thus projects C5 and C6 will use the same plots and trees. Using the calibrated scintillometer data, project C6 will up-scale the functional indicator WUE to the landscape level. Because of their general applicability, functional indicators like WUE are especially useful for modelling approaches.
Das Projekt "Climate indicators on the local scale for past, present and future and platform data management" wird vom Umweltbundesamt gefördert und von Philipps-Universität Marburg, Fachgebiet Klimageographie und Umweltmodellierung durchgeführt. Predicting future climate change is in itself already difficult, especially in such complex ecosystems as the Andean mountain rain and dry forest as well as the Paramo. The common tools to simulate global climate change are global circulation models (GCM). Because of their coarse resolution they are not able to capture atmospheric processes affecting the local climate. For this reason a dynamical downscaling approach will be used to develop a highly resolved spatial and temporal Climatic Indicator System (hrCIS) to derive ecologically relevant climate change indicators affecting the ecosystems of South Ecuador. A local-limited area model (LAM) will be used to (i) generate a highly resolved gridded climatology for present day (hrCISpr) based on reanalysis data and (ii) to generate a highly resolved gridded climatology for projected future (hrCISpf) based on the new Representative Concentration Pathways (RCP) scenario data. The output of the LAM for present day will be validated with in-situ measurement data and satellite-derived products to ensure the accuracy of the model for the simulations of the projected future. On the basis of statistical analysis of both climatologies changes in climate indicators such as air temperature and precipitation regime will be described. The proper storage, curation and accessibility of environmental data is of crucial importance for global change research particularly for monitoring purposes. This proposal will offer an adequate data management system for the Platform for Biodiversity and Ecosystem Monitoring and Research. This will be archived by extending the web-based information management system FOR816DW (a data warehouse for collaborative ecological research units) with features like automatic upload interfaces, a workbench for integrative analysis and an user defined alert system, which will facilitate environmental monitoring for scientist as well as stakeholders. Beside the development of these innovations a main objective is the transfer of knowledge and information (know how, source code, and collection data) to our partners in Ecuador. For this, and to bring together the existing data sources, we cooperate with university and non-university parties in the joint establishment of a Data access platform for environmental data of the region. This will include considerations on long-term accessibility, which is envisaged by a data transfer to the planned German national data infrastructure GFBio.
Das Projekt "Culture experiments on the gamma 13C values recorded in tests of benthic foraminifera from methane sources at high latitudes" wird vom Umweltbundesamt gefördert und von Stiftung Alfred-Wegener-Institut für Polar- und Meeresforschung e.V. in der Helmholtz-Gemeinschaft (AWI) durchgeführt. Since methane is a powerful greenhouse gas, significant releases of methane from instable submarine CH4 clathrates into the atmosphere have been hypothesized as a cause of past and possibly future climate changes (IPCC, 2007). The carbon isotope signature of benthic foraminifers, especially that of Fontbotia wuellerstorfi, has been considered a proxy to detect such clathrate dissociation induced climate changes. However, it has never been experimentally verified to what extent the foraminiferal ä13C signature reflects the release of methane. This is the goal of this project. The necessary experimental preconditions were successfully achieved during the current grant: (1) We established a unique 'high-pressure deep-sea cultivation laboratory' that allows culturing living benthic foraminifers in their original surrounding environment under in-situ (high-pressure) conditions using a newly developed autoclave system. (2) For the first time, this enabled both methane-related high-pressure cultivation experiments and successful reproduction of barophilic F. wuellerstorfi, one of the most important signal-carrier in palaeoceanography. Our future experiments are designed to (1) improve our understanding about the process of ä13C signal transfer from the methane source into the foraminiferal shell; (2) document to what extent the foraminiferal ä13C reflects the biological conversion from the CH4 source into the bottom water, which is measured by the ä13C of the dissolved inorganic carbon; and (3) examine the importance of the food source on the ä13C shell signature.
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