A5ME – EIT – Tank Test Procedure Documentation for Determination of the LH2 Tank Compartment with Natural Damping at 1g

Abstract

For the upper stage of the future version of the Ariane 5, the A5ME, it is important to know the motion of the liquids inside it. One essential motion to understand is the sloshing process. Each spacecraft maneuver leads not only to desired accelerations, there are also accelerations, introduced within the liquids on-board the spacecraft. Due to these forces the liquids are able to start sloshing inside the propellant tanks. The natural damping ratio of sloshing inside the propellant tanks is then an important aspect to understand. Considering that sloshing is feasible at all mission phases, the behavior of the propellant for different fill levels is interesting. Furthermore the sloshing behavior with anti-sloshing devices could be investigated. With the knowledge of the sloshing behavior for each mission phase, it would be possible to optimize maneuvers, so that there are fewer disturbances for the propellant’s free surface and thus fewer self-induced instabilities. In order to further the understanding of this topic DLR Bremen provides, in cooperation with EuroCryospace, tests for sloshing with different fill levels.