A simulation of the propellant storage for a ice-propelled microresistojet engine : Development, verification and validation of a numerical model for the characteristics of a sublimation tank to be used as the propellant storage subsystem for a ice-propel

Abstract: An innovative design for a new type of propulsion sys-tem using sublimating water in solid form as reaction mass, accelerated via a Micro Electric Mechanical System (MEMS) Heater Chip, is currently being developed at the Space Sys-tems Engineering Department at Technische Universiteit Delft in the Netherlands. The aim of the thesis is to char-acterise the propellant storage and gain insight into the physics present in the engine.Two methods of study were used, one theoretical and one experimental. The theoretical part consisted of a one dimensional time-stepping numerical model, the experimen-tal part of a empirical test where the environment and op-erating conditions of the engine are duplicated in a vacuum chamber and data collected on the pressure and tempera-ture inside the test vial.Due to several di˙erent issues with both the model and the tests the accuracy of the obtained results were severely reduced, which made it more diÿcult to compare the ob-tained results from the tests and the model. There was some similarity between the model results and the test re-sults, but the model needs to be refined before it can be used as a input for future models or investigations. The test rig should also be refined to give more accurate refer-ence results.The study did not reveal any critical problems with the engine concept, and the engine still shows promise. The system was shown to be highly interdependent and compli-cated to simulate. Furthermore it was concluded that cre-ating a numerical model from scratch was very challenging. Furthermore the empirical testing requires a very specific environment and needs proper equipment in order to yield accurate results. Conclusions that could be made regard-ing possible future problems with the engine implementa-tion was among others the problem of creating a stable heat balance in the tank. Other issues shown was the problem of the limited power available on a typical CubeSat and that the power requirements of the engine might be larger than what the CubeSat can provide.The engine is however currently in a extremely early development stage, and needs to be further studied before any definite conclusions can be made.