SYMPOSIA PAPER Published: 11 October 2021
STP162620200030

Direct Velocity Measurement of Particle Impacts in Flowing Oxygen Using Photon Doppler Velocimetry

Source

Particle impact is known to be the most common ignition source of metals in oxygen-enriched systems. Because the ignition of materials in particle impact is directly linked to the kinetic energy of impact, having more having accurate velocity measurements is essential for the characterization of this phenomena. Before recent measurements were taken, the velocity profile of particles entrained in the oxygen flow at the White Sands Test Facility (WSTF) were calculated using conservation-of-momentum methods to establish a gas-dynamics model that, supported by dent testing, was accurate to within 10%. Precise measurements would result in more accurate test results and a better understanding of material ignition behavior by particle impact in oxygen-rich environments. Therefore, the WSTF particle impact test system was instrumented with a photon doppler velocimetry (PDV) system to make direct particle velocity measurements. In the course of particle PDV characterization testing, using a single send-and-receive infrared source, a single particle velocity was captured. Due to test configuration constraints, PDV sensors were aligned at various angles to the particle vector in the test chamber. In addition to the typical PDV velocity calculation, angle correction calculations were used to convert apparent velocity to true velocity. The spectral profile of the target projectile is shown to closely follow the calculated gas dynamic model velocities. When a common send-and-receive path is used, the accuracy of the velocity readings are within approximately 3.5% as verified by end-to-end checks against a physical standard. The separation of the send-and-receive beams can produce a higher signal-to-noise ratio, thus further improving velocity measurements.

Author Information

Gallus, Timothy, D.
Materials and Laboratories Dept., NASA Johnson Space Center White Sands Test Facility, Las Cruces, NM, US
Archuleta, Daniel., E.
Materials and Laboratories Dept., NASA Johnson Space Center White Sands Test Facility, Las Cruces, NM, US
Tylka, Jonathan, M.
Materials and Laboratories Dept., NASA Johnson Space Center White Sands Test Facility, Las Cruces, NM, US
Price: $25.00
Contact Sales
Related
Reprints and Permissions
Reprints and copyright permissions can be requested through the
Copyright Clearance Center
Details
Pages: 341–356
DOI: 10.1520/STP162620200030
ISBN-EB: 978-0-8031-7699-7
ISBN-13: 978-0-8031-7698-0