Development of a propulsion system analysis framework for a rocket-propelled airborne testbed with Vertical Take-Off and Landing

The objective of this study is to develop a propulsion system analysis framework for a rocket-propelled aircraft tested with vertical take-off and landing. This is the first phase of a long-term project at the Technical University of Munich, where I conducted my thesis, which will lead to the construction of a real prototype. The project consists in the generation of a group of simulators capable of modelling the proper functioning of the propulsion system. The primary focus of this work is the study of modelling fixed and variable area injectors, to fully understand the differences in performance. The first step was to write a trajectory simulator in the MATLAB-Simulink working environment, which evaluates the thrust required to complete the mission, which consists of taking off to a predefined altitude, maintaining it for a predefined hovering time, and finally soft-landing. Then, by means of a MATLAB algorithm, the required thrust is translated into terms of the required mass flow rate and the possible injectors, with fixed or variable area, are modelled. These data are necessary for the continuation of the project, as the second step is to create a group of simulators of the propulsion system in the EcosimPro ESPSS environment, the differences between the four models created here are between the injectors used and the feed system, pressurised or blowdown. The results of the simulators are reported in this thesis, to verify the correct functioning of the simulators and to evaluate the performance using the different injectors and feed systems. Finally, a parametric analysis is carried out to evaluate the effect of some the change in weight when varying different parameters. The work concludes with a comparison of the results of the different simulators of the propulsion system, so that the best solutions can be evaluated in the future.