DOI: 10.1615/TSFP5
THE TWO-POINT AVERAGE AND THE RELATED SUBGRID MODEL
Краткое описание
In this paper the properties of a simple two-point average have been examined. It results that the associated subgrid stress is expressed by the product of the velocity increments and that its statistical average is related to the second order structure function. It is shown that this result is not peculiar of this particular filtering operator but can be extended to discrete filters and generally to all filtering operator. The energy transfer between the resolved scale and the subgrid scale has been examined both from the point of view of the energy extracted by the subgrid stress and from the point of view of the statistical properties of the structure functions associated to the velocity increment. The two point average applied to a filtered field has been finally examined in the context of the theoretical interpretation of a real large eddy simulation.