TY - JOUR
T1 - Visualizing supersonic inlet duct unstart using planar laser Rayleigh scattering
AU - Do, Hyungrok
AU - Im, Seong Kyun
AU - Mungal, M. Godfrey
AU - Cappelli, Mark A.
N1 - Funding Information:
This work is sponsored by the Department of Energy sponsored Predictive Science Academic Alliance Program (PSAAP) at Stanford University. We thank Dr. Mirko Gamba for useful discussions.
PY - 2011/6
Y1 - 2011/6
N2 - Planar laser Rayleigh scattering (PLRS) from condensed CO2 particles is used to visualize flow structure in a Mach 5 wind tunnel undergoing unstart. Detailed flow features such as laminar/turbulent boundary layers and shockwaves are readily illustrated by the technique. A downstream transverse air jet, inducing flow unchoking downstream of the jet, is injected into the free stream flow of the tunnel, resulting in tunnel unstart. Time sequential PLRS images reveal that the boundary layer growth/separation on a surface with a thick turbulent boundary layer, initiated by the jet injection, propagates upstream and produces an oblique unstart shock. The tunnel unstarts upon the arrival of the shock at the inlet. In contrast, earlier flow separation on the opposite surface, initially supporting a thin laminar boundary layer, is observed when a jet induced bow shock strikes that surface. The resulting disturbance to this boundary layer also propagates upstream and precedes the formation of an unstart shock.
AB - Planar laser Rayleigh scattering (PLRS) from condensed CO2 particles is used to visualize flow structure in a Mach 5 wind tunnel undergoing unstart. Detailed flow features such as laminar/turbulent boundary layers and shockwaves are readily illustrated by the technique. A downstream transverse air jet, inducing flow unchoking downstream of the jet, is injected into the free stream flow of the tunnel, resulting in tunnel unstart. Time sequential PLRS images reveal that the boundary layer growth/separation on a surface with a thick turbulent boundary layer, initiated by the jet injection, propagates upstream and produces an oblique unstart shock. The tunnel unstarts upon the arrival of the shock at the inlet. In contrast, earlier flow separation on the opposite surface, initially supporting a thin laminar boundary layer, is observed when a jet induced bow shock strikes that surface. The resulting disturbance to this boundary layer also propagates upstream and precedes the formation of an unstart shock.
UR - http://www.scopus.com/inward/record.url?scp=79958858117&partnerID=8YFLogxK
U2 - 10.1007/s00348-010-1028-4
DO - 10.1007/s00348-010-1028-4
M3 - Article
AN - SCOPUS:79958858117
SN - 0723-4864
VL - 50
SP - 1651
EP - 1657
JO - Experiments in Fluids
JF - Experiments in Fluids
IS - 6
ER -