Thermal vacuum chamber repressurization with instrument purging

Michael S. Woronowicz

doi:10.1117/12.2238756

27 September 2016 Thermal vacuum chamber repressurization with instrument purging

Michael S. Woronowicz

Proceedings Volume 9952, Systems Contamination: Prediction, Control, and Performance 2016; 99520B (2016) https://doi.org/10.1117/12.2238756
Event: SPIE Optical Engineering + Applications, 2016, San Diego, California, United States

Abstract

At the conclusion of cryogenic vacuum testing of the James Webb Space Telescope Optical Telescope Element Integrated Science Instrument Module (JWST-OTIS) in NASA Johnson Space Center’s (JSCs) thermal vacuum (TV) Chamber A, contamination control (CC) engineers are postulating that chamber particulate material stirred up by the repressurization process may be kept from falling into the Integrated Science Instrument Module (ISIM) interior to some degree by activating instrument purge flows over some initial period before opening the chamber valves. This manuscript describes development of a series of models designed to describe this process. The models are strung together in tandem with a fictitious set of conditions to estimate overpressure evolution from which net outflow velocity behavior may be obtained. Creeping flow assumptions are then used to determine the maximum particle size that may be kept suspended above the ISIM aperture, keeping smaller particles from settling within the instrument module.

Conference Presentation

Citation Download Citation

Michael S. Woronowicz "Thermal vacuum chamber repressurization with instrument purging", Proc. SPIE 9952, Systems Contamination: Prediction, Control, and Performance 2016, 99520B (27 September 2016); https://doi.org/10.1117/12.2238756

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