Implementation of a Physics-Based Behavioral System Model for an Airborne Cryogenic Cooling System

In the system development and test planning phase of physical systems, predicting system behavior — including its operational and critical limits — is of central importance. This paper provides a physics- based behavioral representation of an airborne cryogenic hydrogen cooling system for an electric powertrain. While Model-Based Systems Engineering (MBSE) supports a wide range of perspectives within the broader engineering process, a physics-based approach enables quantitative system behav- ior prediction, virtual system verification, and the development of a targeted Design of Experiment (DoE). Such a framework supports safe and cost-efficient operation of physical system demonstrators during hardware testing. Driven by the system’s functional requirements, the relevant physical phe- nomena are mathematically formulated and translated into a representative model structure. This structure is based on a power balance logic, systematically accounting for all inputs and outputs to predict and monitor key system behavior characteristics. The presented modeling approach is verified against physical system test data. The accuracy in coolant pressure prediction is found to be limited. However, the model meaningfully captures thermal behavior of the system and the physics-based framework provides a robust foundation for predictive simulation and future extensions to more com- plex system configurations.