The pressure-fed rocket cycle is well suited to small engines, but suffers from mass penalties when scaling up to larger systems with higher chamber pressures, making the pump-fed cycle a natural solution to achieve higher performance. Radial inflow turbines (RITs) are of particular interest as they may achieve high pressure ratios in a single stage, leading to compact, high-power-density designs suitable for small-scale open cycle rocket engines.

This thesis investigates the feasibility of RITs for a hypothetical successor to Delft Aerospace Rocket Engineering’s Stratos V rocket. Vaned and vaneless RITs were designed in AxStream and validated against CFD in Ansys CFX. Both satisfied the 24 kW power requirement, enabling the rocket to outperform pressure-fed and electric pump-fed configurations, but exhibited large efficiency losses from tip leakage, high outlet Mach numbers and severe flow separation. The vaneless turbine achieved lower mass flow and higher power, whereas the vaned turbine showed more potential for optimisation through improved stator and volute design. A preliminary design of a more typical axial turbine suggests higher efficiency and practicality, but was not yet validated.