sounding rocket COMPERE experiment
The flight experiment was performed in May, 2008 in Kiruna, Sweden. It has been a benchmark type of experiment on fluid behavior in tanks to test hypotheses and numerical predictions. This experiment has been intended to partially fill in the objectives of the ESA MAP project AO-2004-111 (Convective boiling and condensation). The SOURCE experiment is still going on to serve the needs of the COMPERE research group whose mandate is to investigate the behavior of propellants in spacecraft launcher tanks.
The main element of the SOURCE module is a transparent cylindrical container which is filled with a test liquid (HFE-7000) during the ballistic phase of the sounding rocket. The container has a linear axial temperature distribution which is achieved prior to the launch by heating the upper part. It is pressurized with nitrogen gas at 3 bars.
During and after the filling the cold liquid comes into contact with the hot walls and a thermo-capillary convection sets in. This convection changes the contact angle and deforms the free surface. This phenomenon can only be investigated in zero gravity condition.
The results of the tests have been utilized to validate numerical tools and correlations which are used (and will be used) to design a new cryogenic re-ignitable European upper stage. The long ballistic flight phases require the knowledge of the thermo-hydraulic behavior of the propellant to predict the location of the liquid in the tanks, the temperature distribution in the liquid and gaseous phases, as well as the amount of evaporated liquid and dissolved gas. The compensated gravity conditions during the ballistic flight phases are unique and can not be tested on ground. Tests on a small scaled tank within a sounding rocket provide data for the validation of tools. The results of the tests with a storable liquid will be applied on cryogenic propellants using similarity laws and numerical modeling.
We gratefully acknowledge the support by the European Space Agency (ESA), the French Space Agency (CNES) and the German Aerospace Center (DLR).
Fuhrmann, E., Dreyer, M. E.: Description of the Sounding Rocket Experiment - Source, Microgravity sci. tec. 20/3-4, 205-212 (2008).
Fuhrmann, E., Dreyer M. E.: „Wall Heat Transfer Induced by Surface Tension Driven Flow - a numerical Prediction for a Sounding Rocket Flight Experiment SOURCE”. Proceedings of Third International Symposium on Physical Science in Space 2008, J. Jpn. Soc. Microgravity Appl. Vol. 25 No. 3 2008.
Fuhrmann, E., Dreyer, M. E.: Heat Transfer by Thermo-Capillary Convection, Sounding Rocket COMPERE Experiment SOURCE, Microgravity Sci. Technol., 21 (Suppl. 1), 87-93 (2009).