Model fidelity requirements for closed-Brayton-cycle space power systems

Closed-Brayton-Cycle (CBC) power conversion is a technology that can be used in space power systems for spacecraft, surface bases, and planetary rovers. Various factors, such as turbomachinery efficiency, heat exchanger effectiveness, working fluid composition, and cycle temperatures and pressure are considered while optimizing a CBC power conversion system (PCS). The objective of designing the CBC power conversion system is to demonstrate system-level impacts of fidelity differences in CBC models and to recommend a minimum CBC modeling fidelity for conceptual design studies. The CBC configuration includes basic CBC elements and omits bearings, compressor bleed flow, heat exchanger details, and external subsystem elements that directly influence performance. A more realistic diagram of the system is prepared that includes heat rejection system (HRS) information to understand gas cooler performance and auxiliary loads, such as pumping power.