Scaling
Laws of the Dissipation Rate of Turbulent Charles Meneveau and John O'Neil
ABSTRACT: The energy dissipation term appearing in the transport equation for turbulence subgrid-scale kinetic energy, k, is studied experimentally. Special attention is directed at scaling properties of its moments, which are described using the multifractal formalism. In Large-Eddy-Simulation, the dissipation is usually modeled in terms of k. Therefore, the scaling of moments of k is studied as well. It is found that the latter variable displays a slightly more pronounced level of intermittency than that of the dissipation; a discrepancy whose impact on simulations is difficult to assess a-priori. However, it is shown that the scaling of the expected value of dissipation conditioned upon the local kinetic energy differs markedly from the model prediction. The equation for the probability density function is used to illustrate the importance of correctly predicting this conditional expected value. A new model is proposed, which employs the inverse strain-rate magnitude as time scale. Phys.
Rev. E, 49, pp. 2866-2874 § Archival Journal Publications: Articles may be downloaded for personal use only! |
Charles Meneveau, Department of Mechanical Engineering, Johns Hopkins University, 3400 N. Charles Street, Baltimore MD 21218, USA, Phone: 1-410-516-7802, Fax: 1-(410) 516-7254, email: meneveau@jhu.edu |
||
Last
update:
04/18/2011
|