Improvement and validation of test stand performance for novel micropropulsion systems

Improvement and validation of test stand performance for novel micropropulsion systems

Jansen, E.H.W.

Zandbergen, B.T.C. (mentor)

Aerospace Engineering

Space Engineering

2016-04-26

At the Space Engineering (SpE) department of the Delft University of Technology performance testing of micropropulsion systems is done using the Delft Aerospace Rocket Thrust Stand (DARTS) facility. The DARTS facility has a need for a new improved test stand which can measure the thrust performance of the in-house developed micro-thrusters. The work presented in this Master thesis report addresses this need. This report shows the validation process of a test stand capable of steady-state thrust measurements in a range of 0.1 to 15[mN]. The AE-TB-5m thrust bench is selected to provide these measurement capabilities. The AE-TB-5m test stand has been re-assembled, improved and discrepancies in its measurement characteristics have been successfully identified and solved. A new calibration process for the test stand has been developed to provide full automation in order to mitigate any inconsistencies due to human influence. Furthermore, the measurement accuracies are determined and are found to be below 0.036[mN], which fully complies with the target requirement of 0.1[mN]. The test stand measurement capabilities have been successfully demonstrated in both an atmospheric and vacuum environment using the heritage T3 Micro Propulsion System (T3μPS) thruster test model originating from the Delfi-n3Xt CubeSat mission. Moreover, an empirical relation for the estimation of a loss factor on the thrust coefficient due to viscous effects in low Reynolds number nozzles has been evaluated. The results of this analysis shows improved correlation with experimental data in vacuum conditions and for Reynolds numbers between 5500 and 10000 when compared with ideal rocket theory. The feasibility of an experimental bell-shaped micro nozzle produced using a novel microprecision additive manufacturing technique has been evaluated. The nozzle shape showed a nearly perfect correlation between the designed bell curve and the manufactured product. An axially symmetric bell nozzle of this micron scale is considered a unique engineering accomplishment. The nozzle throat shows incompatibility with a high vacuum environment resulting from inspection with an electron-microscope. Despite a collapsed throat, a leak path trough the throat is successfully identified using the AE-TB-5m, again demonstrating its operational capabilities. The test stand is considered fully operational and ready to enable thrust measurements of other micropropulsion systems at the DARTS facility.

http://resolver.tudelft.nl/uuid:28f0b7fa-1288-4e32-88fd-2e138745714a

Student theses

master thesis

(c) 2016 Jansen, E.H.W.