Open Access100 kHz PLEET velocimetry in a Mach-6 Ludwieg tube
Author(s) -
Paul S. Hsu,
Naibo Jiang,
Joseph S. Jewell,
Josef Felver,
Matthew P. Borg,
Roger L. Kimmel,
Sukesh Roy
Publication year - 2020
Publication title -
optics express
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.391302
Subject(s) - freestream , mach number , hypersonic speed , computational fluid dynamics , optics , velocimetry , scramjet , particle image velocimetry , turbulence , aerospace engineering , physics , shock tube , mechanics , shock wave , reynolds number , engineering , combustor , chemistry , organic chemistry , combustion
Picosecond laser electronic-excitation tagging (PLEET) was demonstrated in a Mach-6 Ludwieg tube at a repetition rate of 100 kHz using a 1064 nm, 100 ps burst-mode laser. The system performance of high-speed velocimetry in unseeded air and nitrogen Mach-6 flows at a static pressure in the range of 5-20 torr were evaluated. Based on time-resolved freestream flow measurements and computational fluid dynamics (CFD) calculations, we concluded that the measurement uncertainty of 100 kHz PLEET measurement for Mach 6 freestream flow condition is ∼1%. The measured velocity profiles with a cone-model agreed well with the CFD computations upstream and downstream of the shockwave; downstream of the shockwave the discrepancy between the CFD and experimental measurement could be attributed to a slight nonzero angle of attack (AoA) or flow unsteadiness. Our results show the potential of utilizing 100 kHz PLEET velocimetry for understanding real-time dynamics of turbulent hypersonic flows and provide the capability of collecting sufficient data across fewer tests in large hypersonic ground test facilities.