Hostname: page-component-586b7cd67f-2plfb Total loading time: 0 Render date: 2024-11-23T11:25:12.779Z Has data issue: false hasContentIssue false

Experimental evidence for the theory of local isotropy

Published online by Cambridge University Press:  24 October 2008

A. A. Townsend
Affiliation:
Emmanuel CollegeCambridge

Extract

Some new measurements of isotropic turbulence produced behind a biplane grid have been made at high Reynolds numbers, and these results are compared with the predictions of the theory of local isotropy developed by A. N. Kolmogoroff. The transverse double-velocity correlation has been measured at mesh Reynolds numbers up to 3·2 × 105, and the observed form agrees well with the predicted form. Measurements of the skewness factor of velocity differences over finite intervals have also been made, and the factor is nearly constant and equal to −0·38, if the interval is small compared with the integral scale. The invariance of dimensionless functions of the velocity derivatives has been confirmed for the flattening factor of ∂u/∂x, namely,

which is nearly constant over a wide range of conditions. It is concluded that the theory of local isotropy is substantially correct for isotropic turbulence of high Reynolds number.

Type
Research Article
Copyright
Copyright © Cambridge Philosophical Society 1948

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

(1)Batchelor, G. K. and Townsend, A. A. In course of publication.Google Scholar
(2)Batchelor, G. K.Proc. Cambridge Phil. Soc. 43 (1947), 533.CrossRefGoogle Scholar
(3)Townsend, A. A.Proc. Cambridge Phil. Soc. 43 (1947), 560.CrossRefGoogle Scholar
(4)Batchelor, G. K. and Townsend, A. A.Proc. Roy. Soc. A, 190 (1947), 354.Google Scholar