Global ETD Search

11	MULTIFUNCTIONAL METAL-FREE CARBON NANOMATERIALS FOR CLEAN ENERGY CONVERSION AND STORAGE APPLICATIONS Chen, Xiaoyi 25 January 2022 (has links) No description available. Chemistry Energy Nanotechnology Carbon metal-free catalyst solar cell water splitting fuel cell Zn-air battery supercapacitor zero emission energy system
12	High Fidelity Analysis of Advanced Turbines for Zero Emission Supercritical CO2 Cycles Logan Michael Tuite (19838748) 14 October 2024 (has links) <p dir="ltr">This research presents a culmination of work into uncovering the underlying fluid dynamic behaviors of supercritical CO2 as it relates to high pressure turbine design using a combined fundamental and practical numerical and experimental analysis. The fundamental analysis of the thermo-fluid dynamic properties of supercritical CO2 boundary layers and separation is analyzed against the air counterparts for non-dimensional quantities of interest – pressure ratio, Mach number, Reynolds number – and combinations of these quantities. The coupling of density derivatives with pressure and temperature are investigated within the operating conditions of the first stage turbine of a supercritical CO2 oxyfuel power cycle. Armed with the information garnered from this analysis, a 3D optimization is run using computational fluid dynamics to investigated nearly 3000 unique blade shapes, focusing on increasing the isothermal corrected efficiency and decreasing the heat load to the blade. Three different families of blade shapes are identified from the analysis and their aerodynamic qualities discussed. A single advanced blade design is chosen for in depth analysis and experimental testing against the baseline blade from which the optimization was started. Mechanical design for the experimental campaign in the Big Rig for Aerothermal Stationary Turbine Analysis (BRASTA) is presented for a novel sector-based off-axis design and the results of the aerothermal measurements discussed. In tandem with blade design and analysis, the Tip Gap Experimental Research Article for Large Scale Injection Layouts (Tiger Lily), a canonical model for the large-scale investigation of tip flows in high Reynolds number flows, is developed and the mechanical and aerodynamic design discussed. Aerothermal analysis for different tip coolant injection configurations is performed using Improved Delayed Detached Eddy Simulation (IDDES) computational fluid dynamics analysis to resolve turbulent structures resulting from coolant injection and over tip flow interaction. Experimental investigation of Tiger Lily is presented, validating the structures and features seen in the numerical analysis. The conclusion of these investigations results in the increased understanding of the underlying fluid dynamic behaviors of supercritical CO2 in high pressure turbines.</p> Supercritical Carbon Dioxide Computational Fluid Dynamics Zero Emission Research Turbomachinery Aerodynamics Turbomachinery Tip Flows Scale-Resolving Simulations
13	Neutral lightweight engineering: a holistic approach towards sustainability driven engineering Kupfer, Robert, Schilling, Levin, Spitzer, Sebastian, Zichner, Marco, Gude, Maik 30 May 2024 (has links) The continuously growing social and political pressure to provide sustainable products is forcing also the lightweight industry to rethink current development and manufacturing processes. While established development approaches in lightweight engineering mainly focus on technical and economical product requirements they usually do not consider sustainability criteria. To address these challenges, a new class within the lightweight disciplines is proposed—the Neutral Lightweight Engineering. Its basic goal is to integrate sustainability criteria in all decisions along the development chain of a lightweight component. The decision makers in lightweight engineering thereby have to consider the whole life cycle of a product system from material sourcing to end-of-life part management. To implement this idea, advanced development methods are necessary, using established and emerging materials as well as efficient production and end-of-life strategies. This concept article introduces the idea of Neutral Lightweight Engineering and exemplary highlights some of its aspects before the background of scientific literature. info:eu-repo/classification/ddc/333.7 ddc:333.7
14	Analysis of a novel thermoelectric generator in the built environment Lozano, Adolfo 05 October 2011 (has links) This study centered on a novel thermoelectric generator (TEG) integrated into the built environment. Designed by Watts Thermoelectric LLC, the TEG is essentially a novel assembly of thermoelectric modules whose required temperature differential is supplied by hot and cold streams of water flowing through the TEG. Per its recommended operating conditions, the TEG nominally generates 83 Watts of electrical power. In its default configuration in the built environment, solar-thermal energy serves as the TEG’s hot stream source and geothermal energy serves as its cold stream source. Two systems-level, thermodynamic analyses were performed, which were based on the TEG’s upcoming characterization testing, scheduled to occur later in 2011 in Detroit, Michigan. The first analysis considered the TEG coupled with a solar collector system. A numerical model of the coupled system was constructed in order to estimate the system’s annual energetic performance. It was determined numerically that over the course of a sample year, the solar collector system could deliver 39.73 megawatt-hours (MWh) of thermal energy to the TEG. The TEG converted that thermal energy into a net of 266.5 kilowatt-hours of electricity in that year. The second analysis focused on the TEG itself during operation with the purpose of providing a preliminary thermodynamic characterization of the TEG. Using experimental data, this analysis found the TEG’s operating efficiency to be 1.72%. Next, the annual emissions that would be avoided by implementing the zero-emission TEG were considered. The emission factor of Michigan’s electric grid, RFCM, was calculated to be 0.830 tons of carbon dioxide-equivalent (CO2e) per MWh, and with the TEG’s annual energy output, it was concluded that 0.221 tons CO2e would be avoided each year with the TEG. It is important to note that the TEG can be linearly scaled up by including additional modules. Thus, these benefits can be multiplied through the incorporation of more TEG units. Finally, the levelized cost of electricity (LCOE) of the TEG integrated into the built environment with the solar-thermal hot source and passive ground-based cold source was considered. The LCOE of the system was estimated to be approximately $8,404/MWh, which is substantially greater than current generation technologies. Note that this calculation was based on one particular configuration with a particular and narrow set of assumptions, and is not intended to be a general conclusion about TEG systems overall. It was concluded that while solar-thermal energy systems can sustain the TEG, they are capital-intensive and therefore not economically suitable for the TEG given the assumptions of this analysis. In the end, because of the large costs associated with the solar-thermal system, waste heat recovery is proposed as a potentially more cost-effective provider of the TEG’s hot stream source. / text Thermoelectric generator TEG Novel thermoelectric generator Thermoelectrics Thermoelectric effect Thermoelectric modules Thermoelectric device Patent application Hot stream source Cold stream source EIA EERE Systems-level analysis Energy balance Control volume analysis Thermodynamic analysis Insolation data Insolation incident on a panel Incident insolation Extraterrestrial insolation NREL Ambient temperature data NOAA Renewable energy sources Energy generation technology Electricity generation technology Thermal energy Coupled system Emissions Greenhouse gas GHG Emissions analysis Zero-emission Emissions avoided Emission factor EF Reliability First Corporation RFC Built environment Integrated into the built environment Solar-thermal energy Solar collector system Photovoltaic thermal PVT panel Thermal storage tank Geothermal energy Geothermal heat pump GHP Ground source heat pump GSHP Numerical analysis Numerical model MATLAB Finite-difference Euler explicit Electric grid Annual energetic performance Annual electricity generation Operating efficiency System efficiency Thermodynamic characterization Economic analysis Levelized cost of energy LCOE Waste heat recovery Carbon dioxide equivalent CO2e Capital costs Installed costs Operating and maintenance costs

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