Measurements of the effect of molecular diffusivity in turbulent diffusion
- 1 January 1960
- journal article
- research article
- Published by Cambridge University Press (CUP) in Journal of Fluid Mechanics
- Vol. 7 (3) , 397-400
- https://doi.org/10.1017/s0022112060000165
Abstract
Townsend (1954) has shown that turbulent vorticity may rotate and strain a diffusion wake, thereby increasing the contribution of molecular diffusion to the total mean dispersion over short diffusion times. To test whether any such effect occurs at longer diffusion times, the lateral dispersion of both helium and of carbon dioxide in air were measured downstream from a continuous point source in the turbulence produced by a grid in a wind tunnel. The data show that, for long diffusion times, accelerated molecular diffusion is negligible, so that molecular diffusion makes only an independent contribution to the total dispersion.Keywords
This publication has 1 reference indexed in Scilit:
- Diffusion in a field of homogeneous turbulenceMathematical Proceedings of the Cambridge Philosophical Society, 1952