Effect of Wall Temperature and Mach Number on the Turbulence Structure of Hypersonic Boundary Layers

2009 ◽  
Author(s):  
Izaak Beekman ◽  
Stephan Priebe ◽  
Matthew Ringuette ◽  
Pino Martin
Keyword(s):  
Mach Number ◽  
Boundary Layers ◽  
Wall Temperature ◽  
Turbulence Structure ◽  
Hypersonic Boundary Layers

Compressibility and Variable Density Effects in Turbulent Boundary layers

2006 ◽  
Vol 129 (4) ◽  
pp. 441-448 ◽  
Author(s):  
Kunlun Liu ◽  
Richard H. Pletcher
Keyword(s):  
Boundary Layer ◽  
Mach Number ◽  
Turbulent Boundary Layer ◽  
Boundary Layers ◽  
Wall Temperature ◽  
Stokes Equations ◽  
Variable Density ◽  
Turbulent Boundary Layers ◽  
Reynolds Analogy ◽  
Density Effects

Two compressible turbulent boundary layers have been calculated by using direct numerical simulation. One case is a subsonic turbulent boundary layer with constant wall temperature for which the wall temperature is 1.58 times the freestream temperature and the other is a supersonic adiabatic turbulent boundary layer subjected to a supersonic freestream with a Mach number 1.8. The purpose of this study is to test the strong Reynolds analogy (SRA), the Van Driest transformation, and the applicability of Morkovin’s hypothesis. For the first case, the influence of the variable density effects will be addressed. For the second case, the role of the density fluctuations, the turbulent Mach number, and dilatation on the compressibility will be investigated. The results show that the Van Driest transformation and the SRA are satisfied for both of the flows. Use of local properties enable the statistical curves to collapse toward the corresponding incompressible curves. These facts reveal that both the compressibility and variable density effects satisfy the similarity laws. A study about the differences between the compressibility effects and the variable density effects associated with heat transfer is performed. In addition, the difference between the Favre average and Reynolds average is measured, and the SGS terms of the Favre-filtered Navier-Stokes equations are calculated and analyzed.

A generalized Reynolds analogy for compressible wall-bounded turbulent flows

2013 ◽  
Vol 739 ◽  
pp. 392-420 ◽  
Author(s):  
You-Sheng Zhang ◽  
Wei-Tao Bi ◽  
Fazle Hussain ◽  
Zhen-Su She
Keyword(s):  
Mach Number ◽  
Prandtl Number ◽  
Boundary Layers ◽  
Turbulent Flows ◽  
Wall Temperature ◽  
Velocity Fields ◽  
Recovery Factor ◽  
Mean Velocity ◽  
Reynolds Analogy ◽  
The Mean

AbstractA generalized Reynolds analogy (GRA) is proposed for compressible wall-bounded turbulent flows (CWTFs) and validated by direct numerical simulations. By introducing a general recovery factor, a similarity between the Reynolds-averaged momentum and energy equations is established for the canonical CWTFs (i.e. pipes, channels, and flat-plate boundary layers that meet the quasi-one-dimensional flow approximation), independent of Prandtl number, wall temperature, Mach number, Reynolds number, and pressure gradient. This similarity and the relationships between temperature and velocity fields constitute the GRA. The GRA relationship between the mean temperature and the mean velocity takes the same quadratic form as Walz’s equation, with the adiabatic recovery factor replaced by the general recovery factor, and extends the validity of the latter to diabatic compressible turbulent boundary layers and channel/pipe flows. It also derives Duan & Martín’s (J. Fluid Mech., vol. 684, 2011, pp. 25–59) empirical relation for flows at different physical conditions (wall temperature, Mach number, enthalpy condition, surface catalysis, etc.). Several key parameters besides the general recovery factor emerge in the GRA. An effective turbulent Prandtl number is shown to be the reason for the parabolic profile of mean temperature versus mean velocity, and it approximates unity in the fully turbulent region. A dimensionless wall temperature, that we call the diabatic parameter, characterizes the wall-temperature effects in diabatic flows. The GRA also extends the analysis to the fluctuation fields. It recovers the modified strong Reynolds analogy proposed by Huang, Coleman & Bradshaw (J. Fluid Mech., vol. 305, 1995, pp. 185–218) and explains the variation of the temperature–velocity correlation coefficient with wall temperature. Thus, the GRA unveils a generalized similarity principle behind the complex nonlinear coupling between the thermal and velocity fields of CWTFs.

Mechanism of stabilization of porous coatings on unstable supersonic mode in hypersonic boundary layers

2021 ◽  
Vol 33 (5) ◽  
pp. 054105
Author(s):  
Tiehan Long ◽  
Ying Dong ◽  
Rui Zhao ◽  
Chihyung Wen
Keyword(s):  
Boundary Layers ◽  
Porous Coatings ◽  
Hypersonic Boundary Layers

scholarly journals Investigation of Gas Seeding for Planar Laser-Induced Fluorescence in Hypersonic Boundary Layers

AIAA Journal ◽  
2015 ◽  
Vol 53 (12) ◽  
pp. 3637-3651 ◽  
Author(s):  
C. J. Arisman ◽  
C. T. Johansen ◽  
B. F. Bathel ◽  
P. M. Danehy
Keyword(s):  
Boundary Layers ◽  
Laser Induced Fluorescence ◽  
Hypersonic Boundary Layers ◽  
Planar Laser Induced Fluorescence ◽  
Planar Laser
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