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651	Probabilistic Multidisciplinary Design Optimization on a high-pressure sandwich wall in a rocket engine application Wahlström, Dennis January 2017 (has links) A need to find better achievement has always been required in the space industrythrough time. Advanced technologies are provided to accomplish goals for humanityfor space explorer and space missions, to apprehend answers and widen knowledges. These are the goals of improvement, and in this thesis, is to strive and demandto understand and improve the mass of a space nozzle, utilized in an upperstage of space mission, with an expander cycle engine. The study is carried out by creating design of experiment using Latin HypercubeSampling (LHS) with a consideration to number of design and simulation expense.A surrogate model based optimization with Multidisciplinary Design Optimization(MDO) method for two different approaches, Analytical Target Cascading (ATC) and Multidisciplinary Feasible (MDF) are used for comparison and emend the conclusion. In the optimization, three different limitations are being investigated, designspace limit, industrial limit and industrial limit with tolerance. Optimized results have shown an incompatibility between two optimization approaches, ATC and MDF which are expected to be similar, but for the two limitations, design space limit and industrial limit appear to be less agreeable. The ATC formalist in this case dictates by the main objective, where the children/subproblems only focus to find a solution that satisfies the main objective and its constraint. For the MDF, the main objective function is described as a single function and solved subject to all the constraints. Furthermore, the problem is not divided into subproblems as in the ATC. Surrogate model based optimization, its solution influences by the accuracy ofthe model, and this is being investigated with another DoE. A DoE of the full factorial analysis is created and selected to study in a region near the optimal solution.In such region, the result has evidently shown to be quite accurate for almost allthe surrogate models, except for max temperature, damage and strain at the hottestregion, with the largest common impact on inner wall thickness of the space nozzle. Results of the new structure of the space nozzle have shown an improvement of mass by ≈ 50%, ≈ 15% and ≈ -4%, for the three different limitations, design spacelimit, industrial limit and industrial limit with tolerance, relative to a reference value,and ≈ 10%, ≈ 35% and ≈ 25% cheaper to manufacture accordingly to the defined producibility model. Multidisciplinary Design Optimization Analytical Target Cascading Multidisciplinary Feasible Space Nozzle Ariane Expander Cycle Engine Upper stage space rocket engine Probabilistic Augmented Lagrangian relaxation Finite element Solid Mechanics Thermodynamics Aerodynamics Industrial approach Latin Hypercube Sampling Factorial Analysis Analysis of Variance Other Physics Topics Annan fysik Aerospace Engineering Rymd- och flygteknik Probability Theory and Statistics Sannolikhetsteori och statistik Vehicle Engineering Farkostteknik Reliability and Maintenance Tillförlitlighets- och kvalitetsteknik Applied Mechanics Teknisk mekanik Computational Mathematics Beräkningsmatematik Fluid Mechanics and Acoustics Strömningsmekanik och akustik
652	Assessing the potential of fuel saving and emissions reduction of the bus rapid transit system in Curitiba, Brazil Dreier, Dennis January 2015 (has links) The transport sector contributes significantly to global energy use and emissions due to its traditional dependency on fossil fuels. Climate change, security of energy supply and increasing mobility demand is mobilising governments around the challenges of sustainable transport. Immediate opportunities to reduce emissions exist through the adoption of new bus technologies, e.g. advanced powertrains. This thesis analysed energy use and carbon dioxide (CO2) emissions of conventional, hybrid-electric, and plug-in hybrid-electric city buses including two-axle, articulated, and biarticulated chassis types (A total of 6 bus types) for the operation phase (Tank-to-Wheel) in Curitiba, Brazil. The systems analysis tool – Advanced Vehicle Simulator (ADVISOR) and a carbon balance method were applied. Seven bus routes and six operation times for each (i.e. 42 driving cycles) are considered based on real-world data. The results show that hybrid-electric and plug-in hybrid-electric two-axle city buses consume 30% and 58% less energy per distance (MJ/km) compared to a conventional two-axle city bus (i.e. 17.46 MJ/km). Additionally, the energy use per passenger-distance (MJ/pkm) of a conventional biarticulated city bus amounts to 0.22 MJ/pkm, which is 41% and 24% lower compared to conventional and hybrid-electric two-axle city buses, respectively. This is mainly due to the former’s large passenger carrying capacity. Large passenger carrying capacities can reduce energy use (MJ/pkm) if the occupancy rate of the city bus is sufficient high. Bus routes with fewer stops decrease energy use by 10-26% depending on the city bus, because of reductions in losses from acceleration and braking. The CO2 emissions are linearly proportional to the estimated energy use following from the carbon balance method, e.g. CO2 emissions for a conventional two-axle city bus amount to 1299 g/km. Further results show that energy use of city bus operation depends on the operation time due to different traffic conditions and driving cycle characteristics. An additional analysis shows that energy use estimations can vary strongly between considered driving cycles from real-world data. The study concludes that advanced powertrains with electric drive capabilities, large passenger carrying capacities and bus routes with a fewer number of bus stops are beneficial in terms of reducing energy use and CO2 emissions of city bus operation in Curitiba. advanced powertrain Advanced Vehicle Simulator ADVISOR Brazil BRT bus rapid transit carbon dioxide CO2 city bus Curitiba driving cycle emissions energy consumption energy efficiency energy use fuel economy hybrid propulsion hybrid-electric parallel hybrid passenger carrying capacity plug-in hybrid-electric Tank-to-Wheel analysis vehicle simulation Analyse Brasilien Emissionen Energieeffizienz Energienutzung Energieverbrauch Fahrzeugsimulation Fahrzeugwirkungsgrad Fahrzyklus Fortschrittlicher Antriebsstrang Hybridantrieb Hybridelektrofahrzeug Kohlenstoffdioxid Kraftstoffverbrauch Passagiertransportkapazität Schnellbussystem Stadtbus Steckdosen-Hybrid Vollhybrid analys bränsleförbrukning drivlina energianvändning energieffektivit energiförbrukning fordonssimulering hybriddrift koldioxidutsläpp körcykel laddhybrid passagerarkapacitet stadsbuss strombuss Energy Engineering Energiteknik Energy Systems Energisystem Vehicle Engineering Farkostteknik

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Probabilistic Multidisciplinary Design Optimization on a high-pressure sandwich wall in a rocket engine application

Assessing the potential of fuel saving and emissions reduction of the bus rapid transit system in Curitiba, Brazil