Closure of second- and third-moment rate equations for diffusion in homogeneous turbulence
- 1 April 1978
- journal article
- Published by AIP Publishing in Physics of Fluids
- Vol. 21 (4) , 525-530
- https://doi.org/10.1063/1.862257
Abstract
Essentially exact closures are presented for the second- and third-moment rate equations for diffusion of a pollutant released at a particular time in homogeneous turbulence. The quasi-Gaussian closure is found to require addition of a down-gradient diffusion term. Explicit dependence upon the time after release is found to be retained by the highest moment gradient term. The second- and third-moment approaches are therefore concluded to be inherently incapable of accurately solving the general problem of pollutants released at different places at different times.Keywords
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