Liquid hydrogen propulsion presents itself as one of the most promising technologies for a zero emission commercial aviation future. However, two of the main challenges are the low volumetric energy density and the cryogenic storage temperature of the fuel. In collaboration with Airbus and the ZEROe project, this work develops a model to predict the response of the liquid hydrogen tank when the thermal insulation is lost and very high amount of heat are transferred to the tank and its pressure is increased. The model includes the most important physics driving the response, and enables the study of the system and its improvement, maximizing the amount of fuel carried while being able to safely control the pressure rise.

Reducing primary energy consumption is vital to mitigate greenhouse gas emissions and enhance energy independence. Organic Rankine Cycle (ORC) systems recover low-temperature waste heat using organic fluids, but transport applications require miniaturised systems (mini-ORCs). Their turbines operate under high pressure ratios, leading to supersonic flows and efficiency losses from trailing-edge shocks. To optimise turbine design under non-ideal compressible fluid dynamics (NICFD) conditions associated with organic fluids, Delft University of Technology developed the ORCHID test rig. This thesis focuses on designing a linear stator cascade test section to enable experimental validation of stator design guidelines, numerical models, and modelling assumptions. Cascade geometries were designed for varying fluid thermodynamic conditions and analysed using CFD. Results show nonideality reduces exit flow angle, while cascade blade loading is strongly influenced by tailboard alignment. Additionally, the number of cascade passages has little impact on the flow field in the centre passge.