Krypton Tagging Velocimetry in the Stevens Shock Tube

Abstract

Krypton Tagging Velocimetry (KTV) is implemented in the flow immediately following the incident shock wave in the Stevens Shock Tube. This is motivated by the long-term goal of using KTV to measure velocity in large-scale impulse facilities. Two example cases are presented in 99% N2/1% Kr at incident shock Mach numbers of 2.86 and 2.94. The velocities as measured by KTV are, in general, higher than those calculated from the shock-speed measurements. The discrepancy is most likely due to the misalignment of splitter plate installed in the shock tube (an expansion fan likely accelerated the flow). A new excitation scheme for KTV is used that results in a higher SNR as compared to previous work. A justification of the alternate scheme is presented via a three energy level model. An overview of the shock tube is given, and a model predicting the non-equilibrium thermodynamic state of the gas immediately following the incident shock is presented.

Two-Dimensional Krypton Tagging Velocimetry (KTV-2D) Investigation of Shock-Wave/Turbulent Boundary-Layer Interaction

“…54 This work utilized the excitation scheme used by Mustafa et al 50 which when compared to the excitation scheme used in previous KTV work, [46][47][48][49] results in approximately twice as much fluorescence. 51 Using this excitation scheme KTV is performed in the following steps according to the energy level diagram shown in Fig. 4.…”

“…used KTV to measure seven simultaneous profiles of streamwise velocity and velocity fluctuations in the incoming boundary layer and immediately upstream of a 24-degree compression corner in a M ∞ = 2.8, Re Θ = 1750, 99% N 2 /1% Kr shock-wave/turbulent boundary-layer interaction. Recently, KTV was implemented in the Stevens Institute of Technology Shock Tube by Mustafa et al51 to measure the freestream velocity behind a Mach 3 shock. In addition, KTV has been demonstrated to work in the freestream of the large-scale AEDC Hypervelocity Tunnel 9 52.…”