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Statistical properties of turbulent density fluctuations

Published online by Cambridge University Press:  29 March 2006

L. N. Wilson  and
R. J. Damkevala
L. N. Wilson
Affiliation:
IIT Research Institute, Chicago, Illinois
R. J. Damkevala
Affiliation:
IIT Research Institute, Chicago, Illinois
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Abstract

The cross-correlation technique has been used to obtain statistical properties of scalar density fluctuations. Two schlieren instruments with their optical beams intersecting in the turbulent field each give a signal proportional to the density gradient in the flow direction but integrated along the beam path. Cross-correlation of the two signals gives an area integral of the density-gradient covariance. For locally isotropic conditions the area integration can exactly compensate for the two gradients giving a result proportional to the local mean-square density fluctuation at the beam intersection point.

Experiments performed in the shear layer of a subsonic jet show results which tend to verify the principles of crossed-schlieren measurement. Intensity levels are close to those predicted assuming density fluctuations are related isentropically to local, incompressible pressure fluctuations.

Type
Research Article
Information
Journal of Fluid Mechanics , Volume 43 , Issue 2 , 28 August 1970 , pp. 291 - 303
Copyright
© 1970 Cambridge University Press

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References

Born, M. & Wolf, E. 1959 Principles of Optics. New York: Pergamon.
Davies, P. O. A. L., Fisher, M. J. & Barratt, M. J. 1963 J. Fluid Mech. 15, 33.
Kistler, A. L., O'Brien, V. & Corrsin, S. 1954 NACA Res. Memo no. RM54d19.
Kline, S. J. 1969 Turbulent boundary layer prediction and structure—the state of the art. Report MD-23, Stanford University.Google Scholar
Fisher, M. J. & Krause, F. R. 1967 J. Fluid Mech. 28, 70.
Liepmann, H. W. & Roshko, A. 1957 Elements of Gas Dynamics. London: Wiley.
Wilson, L. N., Krause, F. R. & Kadrmas, K. A. 1969 In Basic Aerodynamic Noise Research (ed. I. R. Schwarz). NASA SP-207.