THMT-12. Proceedings of the Seventh International Symposium On Turbulence Heat and Mass Transfer
DOI: 10.1615/ICHMT.2012.ProcSevIntSympTurbHeatTransfPal
ISBN Print: 978-1-56700-302-4
ISSN: 2377-2816
Destruction coefficients for mean dissipation rates in grid turbulence
pages 2269-2276
DOI: 10.1615/ICHMT.2012.ProcSevIntSympTurbHeatTransfPal.2330
ABSTRACT
The isotropic forms of the transport equations for the mean turbulent kinetic energy and scalar variance dissipation rates, ‹∈› and ‹χ›, suggest that the turbulent mixing (power-law) decay rates depend on the ratios G/Rλu and Gθ/Rλu, where G and Gθ are destruction coefficients of ‹∈› and ‹χ›, and Rλu is the Taylor microscale Reynolds number. Present measurements and review data on grid turbulence show that, while Gθ/Rλu is nearer to its asymptote than G/Rλu, both ratios asymptote at Rλu ≈ 103, which should correspond to a state of complete self-preservation for the velocity and the passive scalar fields.