Prediction of the Permeation Performance of a Candidate Space Docking Seal

摘要

The preservation of air in manned spacecraft is the utmost priority in space seal research and development Novel elastomeric space seals were developed by NASA for future spacecraft Because a comprehensive prediction methodology was lacking in previous seal research, the design process for these elastomeric space seals had relied heavily on prior knowledge and experimental studies. Recent developments in a compressible permeation method for space seals afforded the ability to predict leak rates for realistic silicone elastomeric space seals. The objective of the research presented herein was to provide a measure of computational validation, comparing experimental referents with corresponding computational predictions. Experimental measurements of a subscale space seal constructed with elastomer compound S0383-70 were performed at two operating temperatures (+73 and +122 °F) and two levels of closure (40 and 100%). The computational technique included a finite difference technique using a curvilinear, body-fitted grid and pseudo-time-stepping to reach steady state. The leak rate performance of the seal was then calculated from a mass flux summation at domain boundaries. The computational analysis showed sound correlation with the experimental measurements at 40% closure because the predicted leak rate values were within the bounds of the experimental uncertainty. At 100% closure, the predicted leak rates were within 16% of the corresponding experimental observations. Differences were attributed to inaccuracies of the domain and the fidelity of the model.