Design and thermal analysis of a cryogenic radiator using V Groove effect for space telescope application

Sammanfattning

This master’s thesis presents the design, analysis, and realization of a cryogenic radiator using V-Groove technology, from initial estimates and conceptual design to elaboration of both a numerical and a physical model in order to create a baseline for future investigations of the key parameters of the V-Groove technology. The approach combined heat transfer theory and the V-Groove effect with simplified digital models, nodal descriptions, analytical formulas, Monte Carlo ray tracing, and deterministic finite element methods and laboratory emissivity measurements. The design process balanced performance optimization and budget constraints. The final physical model, measuring approximately 30x40 cm, features three curved radiator stages designed to cool a hypothetical instrument with an internal heat dissipation of 10 mW, bringing its temperature down to 80 K. Its last stage features a high-emissivity coating used in current space missions, ensuring flight-like thermal behavior. Each stage is separated by custom-made PTFE insulating supports, with dedicated multi-layer insulation for the mounting base and instrument interface. Despite its compact size and the 71% parasitic heat load on the cold patch, the model’s projected performance matches other cryogenic radiant coolers for the same final temperature. Equipped with cryostat integration instrumentation, the model will undergo tests in the CNES laboratory to validate its performance against numerical predictions from Python-based calculations and finite element simulations. These tests will serve as proof of concept, enabling further modifications and sensitivity studies, such as additional stages or new surface coatings.