Reynolds-number dependence of temperature structure functions in turbulent shear flows

1986 ◽  
Vol 34 (4) ◽  
pp. 411-414 ◽  
Author(s):  
R. A. Antonia
Keyword(s):  
Reynolds Number ◽  
Shear Flows ◽  
Structure Functions ◽  
Turbulent Shear ◽  
Temperature Structure ◽  
Turbulent Shear Flows ◽  
Reynolds Number Dependence

Temperature structure functions in turbulent shear flows

1984 ◽  
Vol 30 (5) ◽  
pp. 2704-2707 ◽  
Author(s):  
R. A. Antonia ◽  
E. J. Hopfinger ◽  
Y. Gagne ◽  
F. Anselmet
Keyword(s):  
Shear Flows ◽  
Structure Functions ◽  
Turbulent Shear ◽  
Temperature Structure ◽  
Turbulent Shear Flows

Structure functions of temperature fluctuations in turbulent shear flows

1978 ◽  
Vol 84 (3) ◽  
pp. 561-580 ◽  
Author(s):  
R. A. Antonia ◽  
C. W. Van Atta
Keyword(s):  
Temperature Fluctuations ◽  
Structure Functions ◽  
Inertial Subrange ◽  
Turbulent Shear ◽  
Temperature Structure ◽  
Odd Order ◽  
Even Order ◽  
Inner Region ◽  
Heated Jet ◽  
Reynolds Number Dependence

Structure functions of turbulent temperature and velocity fluctuations are measured both for the atmosphere, in the surface layer over land, and for the laboratory, in the inner region of a thermal boundary layer and on the axis of a heated jet. Even-order temperature structure functions, up to order eight, generally compare favourably with the analysis of Antonia & Van Atta over the inertial subrange. The Reynolds number dependence of these structure functions, as predicted by the analysis, is in qualitative agreement with the measured data. Odd-order temperature structure functions depart significantly from the isotropic value of zero, particularly at large time delays. This departure is reasonably well predicted, over the inertial subrange, by postulating a simple ramp model for the temperature fluctuations. Assumptions involved in this model are directly tested by measurements in the heated jet. The ramp structure does not seriously affect either the even-order temperature structure functions or the mixed velocity-temperature functions, which include even-order moments of the temperature difference.

Kolmogorov constants for structure functions in turbulent shear flows

2007 ◽  
Vol 107 (453) ◽  
pp. 579-589 ◽  
Author(s):  
R. A. Antonia ◽  
A. J. Chambers ◽  
B. R. Satyaprakash
Keyword(s):  
Shear Flows ◽  
Structure Functions ◽  
Turbulent Shear ◽  
Turbulent Shear Flows

scholarly journals Frequency–wavenumber mapping in turbulent shear flows

2015 ◽  
Vol 783 ◽  
pp. 166-190 ◽  
Author(s):  
Roeland de Kat ◽  
Bharathram Ganapathisubramani
Keyword(s):  
Reynolds Number ◽  
High Reynolds Number ◽  
Shear Flows ◽  
Spatial Scales ◽  
Turbulent Shear ◽  
Data Set ◽  
Frequency Spectra ◽  
Taylor’S Hypothesis ◽  
Turbulent Shear Flows ◽  
High Reynolds

Spatial turbulence spectra for high-Reynolds-number shear flows are usually obtained by mapping experimental frequency spectra into wavenumber space using Taylor’s hypothesis, but this is known to be less than ideal. In this paper, we propose a cross-spectral approach that allows us to determine the entire wavenumber–frequency spectrum using two-point measurements. The method uses cross-spectral phase differences between two points – equivalent to wave velocities – to reconstruct the wavenumber–frequency plane, which can then be integrated to obtain the spatial spectrum. We verify the technique on a particle image velocimetry (PIV) data set of a turbulent boundary layer. To show the potential influence of the different mappings, the transfer functions that we obtained from our PIV data are applied to hot-wire data at approximately the same Reynolds number. Comparison of the newly proposed technique with the classic approach based on Taylor’s hypothesis shows that – as expected – Taylor’s hypothesis holds for larger wavenumbers (small spatial scales), but there are significant differences for smaller wavenumbers (large spatial scales). In the range of Reynolds number examined in this study, double-peaked spectra in the outer region of a turbulent wall flow are thought to be the result of using Taylor’s hypothesis. This is consistent with previous studies that focused on examining the limitations of Taylor’s hypothesis (del Álamo & Jiménez, J. Fluid Mech., vol. 640, 2009, pp. 5–26). The newly proposed mapping method provides a data-driven approach to map frequency spectra into wavenumber spectra from two-point measurements and will allow the experimental exploration of spatial spectra in high-Reynolds-number turbulent shear flows.

Sign in / Sign up

Export Citation Format

Share Document