The aviation industry plays a significant role in global connectivity and economic growthbut has substantial negative environmental impacts, particularly in terms of carbondioxide emissions. According to a study by the European parliament, the aviationindustry accounts for 0,4 % of greenhouse gas emissions within the EU and 3,4% forinternational flights. In response to these environmental issues, liquid hydrogen is seenas a promising choice, offering efficiency as a clean energy source, especially whenproduced through electrolysis, as well as higher energy density per volume, making itattractive for the aviation industry where energy and weight optimization are crucial. However, the challenge of using hydrogen as fuel lies in designing a tank that canwithstand extreme conditions, such as low temperature and high pressure , while alsominimizing the risk of flammability and explosion. Additionally the right materials mustbe chosen to resist hydrogen embrittlement. This project aims to design a hydrogentank for aircraft that meets the requirements specified in this study. This will be achievedthrough a literature review, numerical simulations with SolidWorks FEM to test differenttank shapes and materials, and the use of Python code to calculate different spatialparameters.The results indicate that a cylindrical shape is the most optimal choice for the tank, andfour materials have been identified as suitable, with aluminum alloys showing moreadvantages compared to stainless steel due to reduced weight with similar strength.

Le détecteur MINOS a été développé jusqu'à mi-2013 pour la spectroscopie γ prompte de noyaux très exotiques à partir de réactions d’arrachage de protons. Il est composé d'une cible épaisse d'hydrogène liquide pour augmenter la luminosité et d’une chambre à projection temporelle (TPC) pour reconstruire la position du vertex de réaction et de compenser l'effet de la cible épaisse sur la correction Doppler.La chambre à projection temporelle a été développée avec l'expertise du CEA-Irfu sur les détecteurs gazeux de type Micromegas. Dans un premier temps, différentes solutions pour la TPC ont été testées dans une chambre d'essai avec une source α et des mesures de rayons cosmiques. Des muons cosmiques ont été détectés pour la première fois en utilisant la chambre d'essai en début 2013 et ont validé l'utilisation d'un plan de détection Micromegas. Le premier prototype de TPC a été achevé en mai 2013 et nous avons utilisé un banc de rayons cosmiques pour estimer l’efficacité de la TPC.MINOS a ensuite été expédié au Japon et un test de performance sous faisceau a été réalisée à l'installation médicale HIMAC (Chiba, Japon) avec deux cibles minces au lieu de la cible épaisse d'hydrogène pour valider l'algorithme de reconstruction et la résolution de la position du vertex. Un algorithme de reconstruction de traces basé sur la transformée de Hough a été mis au point pour l'analyse des données, testé avec ces données, et comparé à des simulations.La première campagne de physique avec MINOS a eu lieu en mai 2014, avec SEASTAR. Elle s’est concentrée sur la première spectroscopie des ⁶ ⁶ Cr, ⁷⁰,⁷²Fe et ⁷⁸Ni. L'analyse de la spectroscopie du ⁶ ⁶Cr a révélé deux transitions, assignées aux deux premiers états excités. Une interprétation avec des calculs de modèle en couches montre que le maximum de collectivité quadripolaire se produit à N = 40 le long de la chaîne isotopique de chrome.Le ⁶ ⁶Cr est toujours placé dans la région de l’Îlot d’Inversion à N = 40 et les calculs de modèle en couches ainsi que la comparaison avec des calculs basés sur HFB suggèrent une extension de cet Îlot d’Inversion vers N = 50 en dessous du ⁷⁸Ni. L'analyse des ⁷⁰,⁷²Fe effectuée par C. Louchart (TU Darmstadt, Allemagne) révèle la même tendance que pour les isotopes de chrome. Les données et notre interprétation par le modèle en couches suggère une grande collectivité les Cr et Fe riches en neutrons, éventuellement jusqu'à N = 50, ce qui remettrait en cause la solidité de la fermeture de couche N = 50 en dessous du ⁷⁸Ni. / The MINOS device has been developed until mid-2013 for in-beam γ spectroscopy of very exotic nuclei from proton knockout reactions. It is composed of a thick liquid hydrogen target to achieve higher luminosities and a Time Projection Chamber (TPC) to reconstruct the vertex position and compensate for the thick target effect on the Doppler correction.The Time Projection Chamber has been developed with the expertise of CEA-IRFU in gas detectors and Micromegas detectors. At first, different solutions for the TPC were tested in a test chamber with an α source and cosmic-ray measurements. Cosmic rays were detected for the first time using the test chamber in early 2013 and validated the use of a Micromegas detection plane. The first TPC prototype was finished in May 2013, and we used a cosmic-ray bench to estimate the effiiciency of the TPC. The MINOS device was then shipped to Japan and an in-beam performance test was performed at the HIMAC medical facility (Chiba, Japan) with two thin targets instead of the thick hydrogen target to validate the tracking algorithm and the vertex position resolution. A tracking algorithm for the offline analysis based on the Hough transform has been developed, tested with the data, and compared with simulations.The first physics campaign using MINOS took place in May 2014 with SEASTAR. It focused on the first spectroscopy of ⁶ ⁶ Cr, ⁷⁰,⁷²Fe, and ⁷⁸Ni. The analysis of the ⁶⁶Cr spectroscopy revealed two transitions, assigned to the two first excited states. An interpretation with shell model calculations shows that the maximum of quadrupole collectivity occurs at N=40 along the Cr isotopic chain.⁶⁶Cr is still placed in the Island of Inversion region of N=40 and the shell model calculations as well as comparison with HFB-based calculations suggest an extension of this Island of Inversion towards N=50 below ⁷⁸Ni. The analysis of ⁷⁰,⁷²Fe performed by C. Louchart (TU Darmstadt, Germany) reveals the same trend as for Cr isotopes, with a maximum of deformation at N=42. The full data set and our shell-model interpretation suggests a large collectivity for neutron-rich Cr and Fe, possibly up to N=50, questioning the robustness of the N=50 shell closure below ⁷⁸Ni.

[pt] Os combustíveis de baixo impacto ambiental estão em destaque na mídia e na sociedade, atualmente. Neste contexto, o hidrogênio, fonte de energia limpa, tem um grande potencial. Entretanto, ainda não existe uma infraestrutura adequada para sua comercialização. O crescimento da demanda por hidrogênio é de difícil previsão, gerando um alto grau de incerteza na definição das necessidades de capacidades futuras de sua rede logística. Esta dissertação propõe uma metodologia para o planejamento do projeto da cadeia de suprimentos de hidrogênio para uso em transporte. Para representar o problema e avaliar diferentes alternativas de investimentos em infraestrutura logística foi desenvolvido um modelo matemático estocástico de dois estágios utilizando programação linear inteira mista (PLIM). O elevado nível de incerteza desta cadeia aumenta a complexidade do modelo, requerendo uma grande quantidade de cenários, inviabilizando sua otimização. Para contornar esta dificuldade, foi utilizada a técnica de aproximação por média amostral (SAA). Esta abordagem gera soluções, cuja qualidade pode ser estatisticamente avaliada utilizando-se um número reduzido de cenários. A metodologia proposta foi aplicada em um estudo de caso com dados reais da cadeia de suprimentos de hidrogênio líquido da Grã-Bretanha. Os gaps de otimalidade gerados nestes testes foram inferiores a 1 por cento, demonstrando a adequação do método desenvolvido. Mesmo com o alto nível de incerteza do problema, o SAA possibilitou definir como, quando, e onde investir. Os resultados obtidos devem contribuir para proporcionar avanços na criação de uma infraestrutura apropriada para a comercialização do hidrogênio. / [en] Nowadays, fuels with low environmental impact are highlighted in media and society. In this context, hydrogen, as a clean energy source, has a great potential. However, there is still no appropriate infrastructure for its commercialization. The prediction of demand for hydrogen is difficult, generating a high degree of uncertainty in the definition of capacity needs in the future for its logistics network. This work proposes a methodology for the design of the hydrogen supply chain for use in transportation. To represent the problem and evaluate alternatives to invest in logistics infrastructure, a two-stage stochastic mixed-integer programming was developed. The high degree of uncertainty in this chain increases the complexity of the mathematical model, requiring a huge number of scenarios which makes its optimization impossible. To overcome this difficulty, the technique of sample average approximation (SAA) is used. This approach generates solutions, whose quality can be statistically evaluated using a reduced number of scenarios. The proposed methodology was tested in a study case with real data from Great Britain s liquid hydrogen supply chain. The optimal gaps generated in these tests were below 1 percent, demonstrating the adequacy of the developed methodology. Even with the high level of uncertainty of the problem, the propose methodology using SAA technique can define how, when, and where to invest. The results should be helpful in advancing the creation of an appropriate infrastructure for hydrogen commercialization.

Aviation industry is continuously growing especially for very long distance flights due to the globalisation of local economies around the world and the explosive economic growth in Asia. Reducing the time of intercontinental flights from 16-20 hours to 4 hours or less would therefore make the, already booming, ultra-long distance aviation sector even more attractive. To accomplish this drastic travel time reduction for civil transport, hypersonic cruise aircraft are considered as a potential cost-effective solution. Such vehicles should also be fuelled by liquid hydrogen, which is identified as the only viable propellant to achieve antipodal hypersonic flight with low environmental impact. Despite considerable research on hypersonic aircraft and hydrogen fuel, several major challenges should still be addressed before such airliner becomes reality. The current thesis is therefore motivated by the potential benefit of hydrogen-fuelled hypersonic cruise vehicles associated with their limited state-of-the-art.Hypersonic cruise aircraft require innovative structural configurations and thermal management solutions due to the extremely harsh flight environment, while the uncommon physical properties of liquid hydrogen, combined with high and long-term heat fluxes, introduce complex design and technological storage issues. Achieving hypersonic cruise vehicles is also complicated by the multidisciplinary nature of their design. In the scope of the present research, appropriate methodologies are developed to assess, design and optimize the thermo-structural model and the cryogenic fuel tanks of long-range hydrogen-fuelled hypersonic civil aircraft. Two notional vehicles, cruising at Mach 5 and Mach 8, are then investigated with the implemented methodologies. The design analysis of light yet highly insulated liquid hydrogen tanks for hypersonic cruise vehicles indicates an optimal gravimetric efficiency of 70-75% depending on insulation system, tank wall material, tank diameter, and flight profile. A combination of foam and load-bearing aerogel blanket leads to the lightest cryogenic tank for both the Mach 5 and the Mach 8 aircraft. If the aerogel blanket cannot be strengthened sufficiently so that it can bear the full load, then a combination of foam and fibrous insulation materials gives the best solution for both vehicles. The aero-thermal and structural design analysis of the Mach 5 cruiser shows that the lightest hot-structure is a titanium alloy construction made of honeycomb sandwich panels. This concept leads to a wing-body weight of 143.9 t, of which 36% accounts for the wing, 32% for the fuselage, and 32% for the cryogenic tanks. As expected, hypersonic thermal loads lead to important weight penalties (of more than 35%). The design of the insulated cold structure, however, demonstrates that the long-term high-speed flight of the airliner requires a substantial thermal protection system, such that the best configuration (obtained by load-bearing aerogel blanket) leads to a titanium cold design of only 4% lighter than the hot structure. Using aluminium 7075 rather than titanium offers a further weight saving of about 2%, resulting in a 135.4 t wing-body weight (with a contribution of 23%, 25%, 18% and 34% from the TPS, the wing, the fuselage, and the cryogenic tanks respectively). Given the design hypotheses, the difference in weight is not significant enough to make a decisive choice between hot and cold concepts. This requires the current methodologies to be further elaborated by relaxing the simplifications. Investigation of the thermal protection must be extended from one single point to different regions of the vehicle, and the TPS thickness and weight should be considered in the structural sizing of the cold design. More generally, the design process should be matured by including additional (static, dynamic and transient) loads, special structural concepts, multi-material configurations and other parameters such as cost and safety aspects. / Doctorat en Sciences de l'ingénieur et technologie / This thesis was conducted in co-tutelle between University of Sydney and Université Libre de Bruxelles.Professor Dries Verstraete was my supervisor at the University of Sydney (so as a member of SydneyUni), but is automatically registered here as a member of ULB because he worked at ULB almost ten years ago.Ben Thornber is also a member of the University of Sydney but the application does not save it for an unknown reason. / info:eu-repo/semantics/nonPublished

This thesis primarily focuses on the electrochemical properties of the H₂/H⁺ redox couple, at various metallic electrodes in room temperature ionic liquids. Initially, a comprehensive overview of room temperature ionic liquids, RTILs, compared to conventional organic solvents is presented which identifies their favourable properties and applications, followed by a second chapter describing the basic theory of electrochemistry. A third chapter presents the general experimental reagents, instruments and measurements used in this thesis. The results presented in this thesis are summarized in six further chapters and shown as follows. (1) Hydrogenolysis, hydrogen loaded palladium electrodes by electrolysis of H[NTf₂] in a RTIL [C₂mim][NTf₂]. (2) Palladium nanoparticle-modified carbon nanotubes for electrochemical hydrogenolysis in RTILs. (3) Electrochemistry of hydrogen in the RTIL [C₂mim][NTf₂]: dissolved hydrogen lubricates diffusional transport. (4) The hydrogen evolution reaction in a room temperature ionic liquid: mechanism and electrocatalyst trends. (5) The formal potentials and electrode kinetics of the proton_hydrogen couple in various room temperature ionic liquids. (6) The electroreduction of benzoic acid: voltammetric observation of adsorbed hydrogen at a Platinum microelectrode in room temperature ionic liquids. The first two studies show electrochemically formed adsorbed H atoms at a metallic Pt or Pd surface can be used for clean, efficient, safe electrochemical hydrogenolysis of organic compounds in RTIL media. The next study shows the physicochemical changes of RTIL properties, arising from dissolved hydrogen gas. The last three studies looked at the electrochemical properties of H₂/H⁺ redox couple at various metallic electrodes over a range of RTILs vs a stable Ag/Ag⁺ reference couple, using H[NTf₂] and benzoic acid as proton sources. The kinetic and thermodynamic mechanisms of some reactions or processes are the same in RTILs as in conventional organic or aqueous solvents, but other remarkably different behaviours are presented. Most importantly significant constants are seen for platinum, gold and molybdenum electrodes in term of the mechanism of proton reduction to form hydrogen.

<p>In this study, universal databases and semi-empirical correlations are developed for cryogenic two-phase heat transfer and pressure drop in heated tubes undergoing flow boiling.</p>

This master thesis studies alternative energy sources for maritime shipping in Sweden. With current climate goals, and a need for change, the maritime sector currently undergoes intense transitions. For shipping companies to lower their carbon footprint, the need to replace non decarbonised fuels is hence critical. With numerous alternatives, currently being developed, actors are phasing obstacles regarding which energy source that is most mature in terms of technical readiness as well as how adequate it will fulfil current climate goals. This study will analyse four different energy sources, liquid hydrogen (LH2), electro-methanol (emethanol), electro-ammonia (e-ammonia) and wind (sails), and answer which out of these energy sources will be most suitable for actors to adapt. To answer this question, the Technological Innovation System framework has been utilised, and the results has been applied to some chosen climate target actions developed by Swedish authorities. The findings proved that e-methanol currently is most mature and has reached most alignment with current climate goals, followed by LH2/wind and lastly e-ammonia. / Detta examensarbete studerar alternativa energikällor för fraktfartyg i Sverige. Med nuvarande klimatmål, och ett behov av förändring, genomgår den maritima sektorn intensiva omställningar. För att rederier ska kunna sänka sitt koldioxidavtryck är behovet att ersätta icke koldioxidneutrala bränslen därför stort. Med ett flertal alternativ, som för närvarande är under utveckling, står aktörer inför hinder angående vilken energikälla som är mest redo gällande teknikmognadsgrad samt hur adekvat den kommer att uppfylla nuvarande klimatmål. Denna studie kommer att analysera fyra olika energikällor, flytande väte (LH2), elektro-metanol (e-metanol), elektro-ammoniak (e-ammoniak) och vind (segel), och ta reda på vilka av dessa energikällor som är mest lämpad för aktörer att använda sig av. För att svara på denna fråga har ramverket Technological Innovation Systems använts och resultaten har tillämpats på några utvalda klimatmålsåtgärder som tagits fram av svenska myndigheter. Resultaten visade att e-metanol för närvarande är mest mogen och har nått mest anpassning till nuvarande klimatmål, följt av LH2/vind och slutligen e-ammoniak.

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