© 1951 by Oxford University Press
THE PASSAGE OF TURBULENCE THROUGH WIRE GAUZES
( Emmanuel College Cambridge )
Measurements have been made of the turbulent intensities existing after the passage of isotropic turbulence through fine-mesh wire gauzes, and the results have been compared with the predictions of the theory of G. I. Taylor and G. K. Batchelor, who express the intensity reduction in terms of the pressure and refraction coefficients of the gauze. In agreement with the theory, the intensities of transverse components of the transmitted turbulence are considerably greater than that of the longitudinal component, but the degree of anisotropy is less than predicted. Observed reductions in total turbulent energy agree well with the predicted values. Upstream of the gauze, reductions of turbulent intensity are observed in very good agreement with theoretical predictions. It is concluded that the Taylor-Batchelor theory represents sufficiently accurately the motion at the gauze, but that turbulent energy transfer occurring within the zone of influence of the gauze leads to appreciable redistribution of energy between the turbulent velocity components. Outside this zone, energy transfer is comparatively weak, and the subsequent approach to isotropy is extremely slow.