scholarly journals A Preliminary Study of the Longitudinal Merging of Instability Wave Packets and Turbulent Spots in a Hypersonic Boundary Layer

2012 ◽  
Author(s):  
Katya Casper ◽  
Steven Beresh ◽  
Steven Schneider
Keyword(s):  
Boundary Layer ◽  
Wave Packets ◽  
Instability Wave ◽  
Hypersonic Boundary Layer ◽  
Turbulent Spots ◽  
Preliminary Study

scholarly journals Pressure fluctuations beneath instability wavepackets and turbulent spots in a hypersonic boundary layer

2014 ◽  
Vol 756 ◽  
pp. 1058-1091 ◽  
Author(s):  
Katya M. Casper ◽  
Steven J. Beresh ◽  
Steven P. Schneider
Keyword(s):  
Boundary Layer ◽  
Pressure Fluctuation ◽  
Electrical Breakdown ◽  
Pressure Fluctuations ◽  
Spanwise Direction ◽  
Hypersonic Boundary Layer ◽  
Nozzle Wall ◽  
Turbulent Spots ◽  
Fluctuation Field ◽  
Second Mode

AbstractTo investigate the pressure-fluctuation field beneath turbulent spots in a hypersonic boundary layer, a study was conducted on the nozzle wall of the Boeing/AFOSR Mach-6 Quiet Tunnel. Controlled disturbances were created by pulsed-glow perturbations based on the electrical breakdown of air. Under quiet-flow conditions, the nozzle-wall boundary layer remains laminar and grows very thick over the long nozzle length. This allows the development of large disturbances that can be well-resolved with high-frequency pressure transducers. A disturbance first grows into a second-mode instability wavepacket that is concentrated near its own centreline. Weaker disturbances are seen spreading from the centre. The waves grow and become nonlinear before breaking down to turbulence. The breakdown begins in the core of the packets where the wave amplitudes are largest. Second-mode waves are still evident in front of and behind the breakdown point and can be seen propagating in the spanwise direction. The turbulent core grows downstream, resulting in a spot with a classical arrowhead shape. Behind the spot, a low-pressure calmed region develops. However, the spot is not merely a localized patch of turbulence; instability waves remain an integral part. Limited measurements of naturally occurring disturbances show many similar characteristics. From the controlled disturbance measurements, the convection velocity, spanwise spreading angle, and typical pressure-fluctuation field were obtained.

A Measurement of Instability Wave in the Hypersonic Boundary Layer on a Sharp Cone

2011 ◽  
Author(s):  
Keisuke Fujii ◽  
Noriaki Hirabayashi ◽  
Hiroshi Ogawa ◽  
Tadao Koyama ◽  
Shoichi Tsuda ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Instability Wave ◽  
Hypersonic Boundary Layer ◽  
Sharp Cone

Effect of angle of attack on hypersonic boundary-layer stability

AIAA Journal ◽  
1997 ◽  
Vol 35 ◽  
pp. 464-470 ◽  
Author(s):  
Glen P. Doggett ◽  
Ndaona Chokani ◽  
Stephen P. Wilkinson
Keyword(s):  
Boundary Layer ◽  
Angle Of Attack ◽  
Boundary Layer Stability ◽  
Hypersonic Boundary Layer
Sign in / Sign up

Export Citation Format

Share Document