Hydraulic and Thermal 1D Modelling of the LH2-Tank within the CALLISTO Project Using EcoSim Pro/ESPSS

Reusability and sustainability are getting more important in the development of new launch vehicles. Reusable launchers show a proven track record of delivering payloads to orbit with significantly lower costs. CNES, JAXA and DLR formed a trilateral collaboration to face the technical challenges associated with reusability. In propellant management, new operational concerns and safety aspects during flight and after landing must be addressed. In order to analyze the operational processes within the scope of the liquid hydrogen tank, a 1D model of the LH2 tank has been developed considering the thermal environment for the duration of the mission. The model features the capabilities to simulate the entire mission from initial tank chill down, propellant loading, boil-off venting, pre- and in-flight pressurization and draining to post-flight residual propellant venting. This way the required propellant mass, boil-off rates and heat fluxes to the structure can be evaluated. The 1D approach allows for quick changes in design and operational procedures and evaluation of their impact on the tank module during all mission phases. The paper presents the 1D model used by DLR for the LH2 tank development and gives an insight into the critical phases and development goals