Fractal Leakage Prediction Model for Metal O-Ring Seals in Pressure Vessels

Microscale surface defects in metal O-ring seals present a critical vulnerability to the integrity of pressure vessels, potentially compromising containment effectiveness. This study introduces a fractal leakage prediction model that integrates modified fractal contact theory with hydrodynamic principles to characterize and predict seal performance. The feasibility and accuracy of the model are validated through experimental data. Comprehensive numerical investigations further explore the influence of surface morphology and operational parameters on the leakage rate of metal O-ring seals. Results indicate that seal interface leakage rates exhibit a strong dependence on the fractal roughness parameter. Reduced values of this parameter yield improved sealing performance when the fractal dimension and contact force are constant. Moreover, under fixed conditions of fractal roughness and contact force, an increase in fractal dimension corresponds to a reduction in leakage rate. This study identifies the fractal dimension as the primary determinant of microscale geometric complexity and surface characteristics, with higher values effectively mitigating the adverse effects of increased fractal roughness parameter. These findings lay the groundwork for advancing the design and optimization of metal O-ring seals in high-stakes applications.