DOI: 10.1615/ICHMT.2005.AustHeatMassTransfConf
ISBN Print: 978-1-56700-235-5
Approach to the 4/5 and 4/3 Laws for Nearly Homogeneous and Isotropic Turbulence
RÉSUMÉ
Some properties of Yaglom's equation, which relates the second-order scalar structure function to the third-order mixed velocity-scalar structure function, are examined for different Schmidt numbers and in different flow types. Experimental and numerical data for the maximum of the third-order mixed structure function are collected in a variety of flows (box turbulence, grid turbulence, wakes, jets) and compared to its asymptotic value (infinite Reynolds number), in order to investigate whether this quantity exhibits a behaviour which is independent of the flow. For a given Reynolds number, the quantity depends markedly on the Schmidt number (Sc), but the higher Sc, the smaller the difference from the asymptotic value. The quantity does not however seem to be affected by the type of flow, which is in contrast with the behaviour of the velocity third-order structure function.