The transition of the boundary-layer state from laminar to turbulent on a 7° sharp cone in Mach 10 flow is measured using several high-speed optical diagnostics capable of time-resolved measurements of the second-mode instability with high spatial resolution. Specifically, megahertz-rate nitric oxide planar laser-induced fluorescence (NO PLIF) imaging is done at 1 MHz to provide a non-path-integrated visualization of second-mode associated structures in the transitioning boundary layer. A recent variation of focused laser differential interferometry (FLDI), namely, linear array FLDI (LA-FLDI), is also applied for multipoint measurements of frequency content in the transitioning boundary layer. From each data set, the frequency of the most unstable second-mode instability is obtained along with the phase velocity of the second-mode waves. Measurements show good agreement relative to each other and also with surface pressure sensors and high-speed schlieren imaging. Furthermore, the 1 MHz NO PLIF imaging demonstrated here shows great potential for visualization of transitional and turbulent boundary layers when path-integrated diagnostics cannot be used.
Megahertz-Rate Imaging of Hypersonic Boundary-Layer Instabilities in a Mach 10 Shock Tunnel
AIAA Journal ; 61 , 2 ; 534-542
2022-10-25
9 pages
Article (Journal)
Electronic Resource
English
HYPERSONIC BOUNDARY-LAYER TRANSITION EXPERIMENTS IN A MACH-6 QUIET TUNNEL
British Library Conference Proceedings | 2010
|Measuring Transition and Instabilities in a Mach 6 Hypersonic Quiet Wind Tunnel
British Library Conference Proceedings | 2014
|MHZ-RATE NO PLIF IMAGING IN A MACH 10 HYPERSONIC WIND TUNNEL
British Library Conference Proceedings | 2010
|