Liquid hydrogen-powered aircraft are a promising candidate for reducing aviation’s climate impact, but safe integration requires crashworthiness considerations already at conceptual design. This work presents a parametric, knowledge-based methodology to design and analyse a fuselage-located cryogenic tank supported by a belly crash structure under a vertical drop test. The methodology is implemented in a parametric application that automatically generates geometry from readily adjustable inputs, enabling quick generation of a wide variety of configurations. A baseline configuration, consisting of 12 sub-tank X-beams per bay configured in six X-crosses, a stiff crossbeam design, and distributed Kevlar tank suspension ropes, exhibited favourable deformation kinematics. A design-of-experiments study was conducted and combined with a surrogate-model-based sensitivity analysis to identify the dominant design parameters governing the crash response. Results show that the coupled frame and crossbeam thickness, together with the crash coefficient, are the most influential. Including a crash structure substantially increases the required tank and fuselage length, and the associated mass penalty is dominated by the added tank and fuselage structure rather than by the crash structure mass. The developed model provides a basis for further research on structural mass optimisation and for providing data for a surrogate integration into a conceptual aircraft design tool. ... Read more

The integration of Generative Artificial Intelligence (GenAI) in engineering presents both opportunities and challenges, particularly in complex, safety-critical systems. This thesis explores two key aspects: (1) developing an AI-powered reverse engineering tool for Knowledge-Based Engineering (KBE) applications and (2) designing a communication framework to enhance interdisciplinary collaboration in AI-driven projects. The aerospace engineering component introduces the REProcess tool, leveraging Large Language Models (LLMs) to extract structured process representations from KBE applications, improving traceability and automation. The science communication component investigates collaboration barriers between AI experts and domain specialists, leading to the development of a structured ideation matrix for GenAI-powered automation systems. Together, these contributions demonstrate how Explainable AI principles can facilitate the adoption of GenAI in engineering workflows while bridging communication gaps. This interdisciplinary approach provides practical methodologies to enhance AI-driven engineering processes, ensuring both technical feasibility and effective human-AI collaboration. ... Read more

The increase in air traffic creates the need for more efficient aircraft. Current design trends of increasing efficiency and reducing fuel consumption also lead to an increase in NOx emissions. Environmental considerations and regulations create a demand for aircraft engine technology with NOx emissions lower than that of current engines. The Steam Injected Water Recovering Turbofan engine is proposed; it injects steam before the combustion chamber and recovers it through condensation in a heat exchanger. Moreover, the cycle recovers more heat from the exhaust gasses, using them as a heat source in a Rankine cycle. The SIWRT was modeled in NPSS in collaboration with GKN Aerospace Sweden AB, to better understand this configuration. A new method was devised to model heat exchanger performance, referred to as a 'variable Cp NTU', capable of taking into account phase change. This new method was verified and partially validated. The engine was studied in a range of water to air of 1% to 7%. It was determined that it is capable of reducing thrust specific fuel consumption by up to 8\% and NOx emissions by up to 66% compared to a conventional future turbofan. Increasing WAR leads to an increase in the fan bypass ratio (FBPR) mostly by reducing the core size. The SIWRT displays design trends similar to conventional turbofan when varying overall pressure ratio, combustor outlet temeperature, and fan pressure ratio. At top of climb the condenser was not able to condense enough water for the engine to self sustain, thus extra water was supplied through an on board reservoir. The research questions were answered, and concluding remarks with suggestions for future work were provided. ... Read more

Aviation has a significant contribution to climate change, which must be decreased. The A321 APPU could offer a substantial improvement, by introducing a hydrogen-powered Auxiliary Power and Propulsion Unit (APPU). This turboshaft engine is located in the tail cone and powers a boundary layer ingestion propulsor, taking over 10% of the thrust. The Steam Injection and Recovery (SIR) cycle is introduced to improve the efficiency of the APPU. This semi-closed water cycle can reduce fuel consumption and NOx emissions. Both the baseline and SIR APPU are modelled in pyCycle, an open-source gas turbine parametric analysis tool. Water properties and heat exchangers are added so pyCycle can model the SIR cycle. The baseline APPU has a thermal efficiency of 45% and a mass of 502 kg. The SIR cycle can increase the efficiency by 1.54% and decrease the NOx emissions by 33.4%, at the cost of a 15.7% mass increase. ... Read more