Thermal-hydraulic-mass performance of a ram air heat exchanger with triply periodic minimal surface Gyroid fins for aircraft cabin thermal management

As more electric aircraft trend toward high power density, aircraft power cabins thermal management has emerged as a critical performance bottleneck. A synergistic cooling scheme coupling nacelle ventilation with internal liquid cooling is proposed, featuring triply periodic minimal surface Gyroid fins as a superior alternative to traditional structures. High fidelity numerical models, validated by wind tunnel experiments, characterize the thermal-hydraulic coupling mechanisms of Gyroid versus traditional louvered fins under typical aviation conditions with an air velocity range of 16-28 m/s. The continuous, smooth Gyroid topology effectively suppresses flow separation and eliminates heat transfer dead zones, delivering a dimensionless heat dissipation gain over 3.37 times that of louvered baselines. Despite an air side pressure drop increase approximately two orders of magnitude and a mass penalty of 17.8% inherent to high specific surface areas, the mass based performance evaluation criterion consistently exceeds unity, peaking at 1.14 and underscoring a clear topological advantage for system compactness. Parametric analysis reveals that while thicker walls bolster solid conduction, the ensuing channel constriction causes disproportionate flow resistance, with a 0.5 mm thickness providing the optimal thermal-hydraulic-mass trade off. These results establish a quantitative foundation for the lightweight, high efficiency thermal management of next generation high power density propulsion systems.