NASA LogoNTRSNTRS - NASA Technical Reports ServerSearchmore_vertCollectionsAboutNewsHelpLogin Back to ResultsStructural Dynamic Assessment of the GN2 Piping System for NASA's New and Powerful Reverberant Acoustic Test FacilityThe National Aeronautics and Space Administration (NASA) Glenn Research Center (GRC) has led the design and build of the new world-class vibroacoustic test capabilities at the NASA GRC's Plum Brook Station in Sandusky, Ohio, USA from 2007 to 2011. SAIC-Benham has completed construction of a new reverberant acoustic test facility to support the future testing needs of NASA's space exploration program and commercial customers. The large Reverberant Acoustic Test Facility (RATF) is approximately 101,000 cubic feet in volume and was designed to operate at a maximum empty chamber acoustic overall sound pressure level (OASPL) of 163 dB. This combination of size and acoustic power is unprecedented amongst the world s known active reverberant acoustic test facilities. Initial checkout acoustic testing was performed on March 2011 by SAIC-Benham at test levels up to 161 dB OASPL. During testing, several branches of the gaseous nitrogen (GN2) piping system, which supply the fluid to the noise generating acoustic modulators, failed at their T-junctions connecting the 12 in. supply line to their respective 4 in. branch lines. The problem was initially detected when the oxygen sensors in the horn room indicated a lower than expected oxygen level from which was inferred GN2 leaks in the piping system. In subsequent follow up inspections, cracks were identified in the failed T-junction connections through non-destructive evaluation testing. Through structural dynamic modeling of the piping system, the root cause of the T-junction connection failures was determined. The structural dynamic assessment identified several possible corrective design improvements to the horn room piping system. The effectiveness of the chosen design repairs were subsequently evaluated in September 2011 during acoustic verification testing to 161 dB OASPL.Document ID20120012960Acquisition SourceGlenn Research CenterDocument TypeTechnical Memorandum (TM)AuthorsMcNelis, Mark E.*(NASA Glenn Research Center Cleveland, OH, United States)*Staab, Lucas D.*(NASA Glenn Research Center Cleveland, OH, United States)*Akers, James C.*(NASA Glenn Research Center Cleveland, OH, United States)*Hughes, William O.*(NASA Glenn Research Center Cleveland, OH, United States)*Chang, Li C.*(NASA Glenn Research Center Cleveland, OH, United States)*Hozman, Aron D.*(NASA Glenn Research Center Cleveland, OH, United States)*Henry, Michael W.*(NASA Glenn Research Center Cleveland, OH, United States)*Date AcquiredAugust 26, 2013Publication DateJune 1, 2012Subject CategoryStructural MechanicsReport/Patent NumberNASA/TM-2012-217610E-18194Meeting InformationMeeting: 27th Aerospace Testing Seminar (ATS)Location: Los Angeles, CACountry: United StatesStart Date: October 16, 2012End Date: October 18, 2012Sponsors:Aerospace Corp.Funding Number(s)WBS: WBS 644423.10.34.03.03.03.22Distribution LimitsPublicCopyrightWork of the US Gov. Public Use Permitted.Available DownloadsNameType20120012960.pdfSTIcloud_downloadcontent_copyvisibilityRelated RecordsThere are no records associated with this record.visibility_offNo Preview Available
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