Development of Spectroscopic Tools to Study Rarefied Gas Flows in Non-Equilibrium
Abstract
Satellites, such as CubeSats, are used for a variety of educational and scientific purposes including surveillance, communication, and research. Their utility while in orbit can be greatly enhanced and prolonged by propulsion mechanisms such as micro-resistojets, which operate by expansion of gas through the nozzle. Although computer simulations have progressed in describing the high-speed viscous flow, experimental efforts are needed to validate and verify these models. Because of the low pressures (< 1 Torr) in which micro-resistojets operate and because of the high spatial resolution (100 um) required to resolve the nozzle exhaust at its exit diameter (1-2 mm), diagnostics of the micro-resistojet exhaust are difficult to achieve. To address this obstacle, a fiber-coupled, multiple-pass cell for spontaneous Raman scattering spectroscopy of the nozzle exhaust in a vacuum chamber was developed. Proof of principle measurements are successfully performed and illustrated at 1 Torrand 500 mTorr for H2 thermometry. Each spectral acquisition takes 15 and 30 minutes, respectively.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 31, 2019
- Accession Number
- AD1090906
Entities
People
- Alfreso D. Tuesta
- Brian T. Fisher
- Logan T. Williams
- Michael F. Osborn
Organizations
- United States Naval Research Laboratory