title: Seedless velocimetry at 100  kHz with picosecond-laser electronic-excitation tagging.
abstract: Picosecond-laser electronic-excitation tagging (PLEET), a seedless picosecond-laser-based velocimetry technique, is demonstrated in non-reactive flows at a repetition rate of 100 kHz with a 1064 nm, 100 ps burst-mode laser. The fluorescence lifetime of the PLEET signal was measured in nitrogen, and the laser heating effects were analyzed. PLEET experiments with a free jet of nitrogen show the ability to measure multi-point flow velocity fluctuations at a 100 kHz detection rate or higher. Both spectral and dynamic mode decomposition analyses of velocity on a Ma=0.8 free jet show two dominant Strouhal numbers around 0.24 and 0.48, respectively, well within the shear-layer flapping frequencies of the free jets. This technique increases the laser-tagging repetition rate for velocimetry to hundreds of kilohertz. PLEET is suitable for subsonic through supersonic laminar- and turbulent-flow velocity measurements.
authors.forename: Naibo
authors.initials: N
authors.lastname: Jiang
authors.forename: Jason G
authors.initials: JG
authors.lastname: Mance
authors.forename: Mikhail N
authors.initials: MN
authors.lastname: Slipchenko
authors.forename: Josef J
authors.initials: JJ
authors.lastname: Felver
authors.forename: Hans U
authors.initials: HU
authors.lastname: Stauffer
authors.forename: Tongxun
authors.initials: T
authors.lastname: Yi
authors.forename: Paul M
authors.initials: PM
authors.lastname: Danehy
authors.forename: Sukesh
authors.initials: S
authors.lastname: Roy