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Full-Text Articles in Engineering
Experimental Investigation Of Leak-Rate Performance Of A Subscale Composite Elastomer-Retainer Docking Seal, Nicholas Garafolo, Christopher Daniels
Experimental Investigation Of Leak-Rate Performance Of A Subscale Composite Elastomer-Retainer Docking Seal, Nicholas Garafolo, Christopher Daniels
Dr. Nicholas Garafolo
A novel docking seal was investigated for application to the main interface seal of NASA’s low-impact docking system. This interface seal was designed to maintain acceptable leak rates while being exposed to the harsh environmental conditions of outer space. In this experimental evaluation, the leak rate of a candidate docking-seal assembly was characterized and evaluated. The composite seal was manufactured from silicone elastomer S0383-70, vacuum molded into a metal retaining ring. Four seal designs were considered with unique characteristic heights. The leak-rate performance was characterized through a mass point leak-rate method by monitoring gas properties within an internal control volume. …
Effect Of System Variables On The Uncertainty Of The Mass Point Leak Rate Methodology Using First-Order Regression, Christopher Daniels, Nicholas Garafolo
Effect Of System Variables On The Uncertainty Of The Mass Point Leak Rate Methodology Using First-Order Regression, Christopher Daniels, Nicholas Garafolo
Dr. Nicholas Garafolo
Advances in nondestructive testing for leak rate characterisation are rare because procedures are well accepted; however, for many critical applications, an understanding of the accuracy and reliability of a reported leak rate is equally as important as the leak rate itself (e.g., manned spacecraft and nuclear power industry). Although it is known that the mass point leak rate method can achieve high accuracies, the measurement uncertainty and limitations of the method are less understood. Using a least-squares regression on a mass–time population and a statistical analysis of regression uncertainty, this study investigated the influence of (1) differential pressure, (2) steady-state …
A Compressible Permeation Approach To Elastomeric Space Seal Characterization, Nicholas Garafolo, Christopher Daniels
A Compressible Permeation Approach To Elastomeric Space Seal Characterization, Nicholas Garafolo, Christopher Daniels
Dr. Nicholas Garafolo
The development of elastomeric face seals is imperative for NASA’s manned space flight program. Lacking in the development of state-of-the-art space seals was a technique for predicting the performance of candidate designs prior to experimental characterization. To this end, a physics-based model for compressible permeation in elastomeric face seals was developed to provide a predictive methodology for designers and researchers. In this novel approach for seal research, compressibility effects and the dependence of permeability on pressure was retained. Two independent permeation parameters arose from an exact, analytical solution to the one-dimensional permeation transport equations. The application of the derived transport …