TY - JOUR
T1 - Experiments on the structure and scaling of hypersonic turbulent boundary layers
AU - Williams, Owen J.H.
AU - Sahoo, Dipankar
AU - Baumgartner, Mark L.
AU - Smits, Alexander J.
N1 - Funding Information:
The support of NASA under Cooperative Agreement no. NNX08AB46A (Program Manager C. McGinley) is gratefully acknowledged. R. Bogart and D. Hoffman provided invaluable assistance setting up the experiments.
Publisher Copyright:
© 2017 Cambridge University Press.
PY - 2018/1/10
Y1 - 2018/1/10
N2 - Particle image velocimetry and filtered Rayleigh scattering experiments were performed over a range of Reynolds numbers to study the scaling and structure of a smooth, flat-plate turbulent boundary layer with a free stream Mach number of 7.5. The measurements indicate few, if any, dynamic differences due to Mach number. Mean and fluctuating streamwise velocities in the outer layer show strong similarity to incompressible flows at comparable Reynolds numbers when scaled according to van Driest and Morkovin. In addition, correlation lengths and structure angles based on velocity statistics were found to be less sensitive to compressibility than indicated by previous studies based on density fields or mass-weighted statistics, suggesting that the density and velocity fields obey different scaling. Finally, the boundary layer displays uniform momentum zones, with the number of these zones similar to incompressible boundary layers at comparable Reynolds numbers.
AB - Particle image velocimetry and filtered Rayleigh scattering experiments were performed over a range of Reynolds numbers to study the scaling and structure of a smooth, flat-plate turbulent boundary layer with a free stream Mach number of 7.5. The measurements indicate few, if any, dynamic differences due to Mach number. Mean and fluctuating streamwise velocities in the outer layer show strong similarity to incompressible flows at comparable Reynolds numbers when scaled according to van Driest and Morkovin. In addition, correlation lengths and structure angles based on velocity statistics were found to be less sensitive to compressibility than indicated by previous studies based on density fields or mass-weighted statistics, suggesting that the density and velocity fields obey different scaling. Finally, the boundary layer displays uniform momentum zones, with the number of these zones similar to incompressible boundary layers at comparable Reynolds numbers.
KW - boundary layer structure
KW - compressible boundary layers
KW - turbulent boundary layers
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U2 - 10.1017/jfm.2017.712
DO - 10.1017/jfm.2017.712
M3 - Article
AN - SCOPUS:85034605835
SN - 0022-1120
VL - 834
SP - 237
EP - 270
JO - Journal of Fluid Mechanics
JF - Journal of Fluid Mechanics
ER -