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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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High speed compression waves, rarefaction waves and gas interface regions position and velocity measurement in shock tube by sensing electrical impedance
Shock tube thermochemistry tables for high temperature gases
Turbulent boundary layer effects on chemical and kinetic measurements of gas mixture composition from nonuniform shock tube flow
Thermal dissociation rate of undiluted nitrogen in shock tube over 5700 to 12,000 K range, using pressure measurements
Thin metal shutter that is forced into angled optical slit isolates spectrograph from high speed shock tube both optically and mechanically so neither radiation nor particulate material enters spectrograph.
Annular-arc accelerator consists of cold gas driver, expansion section, electrode sections, and shock tube section. Triggering improvement provides higher velocities and reduces contamination.
Spectroscopic experiments with gas-driven shock tube - technical developments, redundant measurements of plasma state, and atomic line strengths for neutral carbon
The general design and operating conditions of NASA Ames's electric arc drive shock tube facility are described, and the measurements conducted at the facility to support the development of a theoretical model of the effects of chemical nonequilibrium over a hypersonic vehicle are summarized. In particular, attention is given to the results of measurements at a shock velocity of 6.20 km/s in 1 Torr nitrogen and measurements at a shock velocity of 10.2 km/s in 0.1 Torr air. The discussion covers reaction rate measurement, the use of holographic interferometry, and measurements of vibrational populations using Raman scattering.
Van der Waals broadened Si lines measurements using shock tube and scanning Fabry-Perot interferometer
Multiband radiative cooling effect on enthalpy distribution behind incident wave in cylindrical shock tube for air, using differential approximation
Potential high performance shock tube for high pressure opacity measurements of gaseous rocket propellants for nuclear rocket engines
High temperature plasmas optical properties measurement by plasma spectroscopy, using gas driven shock tube as light source
Predicted flow nonuniformities due to laminar and turbulent boundary layer buildup in shock tubes, studying effects on dissociation rates of bromine in argon mixture
The high strain rate mechanical response of thin polymer plates has been studied using a modified shock tube. Diagnostics include the pressure-time history of the incident and reflected pulses and the use of digital image correlation (DIC) techniques to extract the time-history of the out-of-plane displacement distribution. Additionally, finite element models have been developed to understand the plate response and to validate and modify plate material constitutive models that have been proposed.
A computer program in FORTRAN 4 language was written to determine shock tube, expansion tube, and expansion tunnel flow quantities for real-air test gas. This program permits, as input data, a number of possible combinations of flow quantities generally measured during a test. The versatility of the program is enhanced by the inclusion of such effects as a standing or totally reflected shock at the secondary diaphragm, thermochemical-equilibrium flow expansion and frozen flow expansion for the expansion tube and expansion tunnel, attenuation of the flow in traversing the acceleration section of the expansion tube, real air as the acceleration gas, and the effect of wall boundary layer on the acceleration section air flow. Charts which provide a rapid estimation of expansion tube performance prior to a test are included.
Shock tube spectral measurements of electron recombinations with nitrogen and oxygen ions in far UV radiation range
Instrument provides information on spatial distribution of electron density of gas flow in high-performance shock tube. System permits measurement of profiles of hydrogen-alpha and -beta lines with enough spectral range to record spectral features from the near ultraviolet to the long-wavelength cutoff of photographic film.
UV Fe I, Cr I and II lines gf values obtained by flash absorption spectroscopy on pressure driven shock tube