Skip to main content
Log in

Optical technique for direct measurement of power spectra in compressible turbulence

  • Originals
  • Published:
Experiments in Fluids Aims and scope Submit manuscript

Abstract

We present exploratory tests of a new optical method which measures directly two components of the 3-D power spectrum of the refractive-index fluctuation. The method was applied to a Mach 2 turbulent shear layer. Length scales of 0.1 mm to 1.0 mm were resolved within a shear-layer thickness ranging from 5 mm to 10 mm. At low-to-moderate wavenumbers, the spectral behavior is roughlyκ −3, while at higher wavenumbers it isκ −3.7. These spectral slopes are in agreement with prevailing theoretical predictions for anisotropic (low-wavenumber) and isotropic (high-wavenumber) turbulence.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

Abbreviations

a :

speed of sound

l :

eddy size

n :

refractive index

S :

mean strain rate

S h :

mean shear

T :

static temperature

U :

freestream velocity

x :

axial direction

y :

transverse direction

z :

spanwise direction

δ :

shear-layer thickness

δ′:

=dδ/dx: growth rate

ɛ :

viscous dissipation

ΔU :

=U 1U 2

κ :

wavenumber

ϱ :

density

Φ :

3-D power spectrum

1:

fast stream

2:

slow stream

References

  • Albrecht GF;Robey HE;Moore TR (1990) Optical technique for the measurement of turbulent spectra using the photorefractive properties of BaTiO3. Appl Phys Lett 57: 864–866

    Article  Google Scholar 

  • Brigham EO (1974) The Fast Fourier Transform. New Jersey: Prentice Hall

    Google Scholar 

  • Clifford SF (1978) The Classical Theory of Wave Propagation a Turbulent Medium. Topics in Appl Phys 25: 26–43

    Google Scholar 

  • Elliott GS;Samimy M (1990) Compressibility effects in free shear layers. Phys Fluids A 29: 1231–1240

    Google Scholar 

  • Robey HF (1990) Spectrum of a passive scalar in the inertial-convective subrange of an anisotropic turbulent flow. Phys Rev Lett 65: 1360–1361

    Article  Google Scholar 

  • Robey HF; Albrecht GF; Moore TR (1990) An optical technique for direct measurement of 2-D spectral density of a passive scalar in a turbulent flow. AIAA-90-1667

  • Papamoschou D;Roshko A (1988) The compressible turbulent shear layer: an experimental study. J Fluid Mech 197: 453–477

    Google Scholar 

  • Papamoschou D; Robey HF; Lin M; Bunyajitradulya A (1993) Non-intrusive technique for measurement of power spectra in compressible turbulence. AIAA-93-0633

  • Tennekes H;Lumley JL (1972) A First Course in Turbulence. Cambridge: MIT Press

    Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Additional information

]This study was funded by a grant from Lawrence Livermore National Laboratory and by a grant from the California Space Institute. DP is indebted to HFR and Dr. Alfred C. Buckingham of LLNL for their support.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Papamoschou, D., Robey, H.F. Optical technique for direct measurement of power spectra in compressible turbulence. Experiments in Fluids 17, 10–15 (1994). https://doi.org/10.1007/BF02412798

Download citation

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF02412798

Keywords

Navigation