title: Mach-number-invariant mean-velocity profile of compressible turbulent boundary layers.
abstract: A series of Mach-number- (M) invariant scalings is derived for compressible turbulent boundary layers (CTBLs), leading to a viscosity weighted transformation for the mean-velocity profile that is superior to van Driest transformation. The theory is validated by direct numerical simulation of spatially developing CTBLs with M up to 6. A boundary layer edge is introduced to compare different M flows and is shown to better present the M-invariant multilayer structure of CTBLs. The new scalings derived from the kinetic energy balance substantiate Morkovin's hypothesis and promise accurate prediction of the mean profiles of CTBLs.
authors.affiliation: State Key Laboratory of Turbulence and Complex Systems, College of Engineering, Peking University, Beijing, China.
authors.forename: You-Sheng
authors.initials: YS
authors.lastname: Zhang
authors.forename: Wei-Tao
authors.initials: WT
authors.lastname: Bi
authors.forename: Fazle
authors.initials: F
authors.lastname: Hussain
authors.forename: Xin-Liang
authors.initials: XL
authors.lastname: Li
authors.forename: Zhen-Su
authors.initials: ZS
authors.lastname: She