Abstract
A detailed examination is performed of the relationship between stochastic Lagrangian models—used in PDF methods—and second‐moment closures. To every stochastic Lagrangian model there is a unique corresponding second‐moment closure. In terms of the second‐order tensor that defines a stochastic Lagrangian model, corresponding models are obtained for the pressure‐rate‐of‐strain and the triple‐velocity correlations (that appear in the Reynolds‐stress equation), and for the pressure‐scrambling term in the scalar flux equation. There is an advantage in obtaining second‐moment closures via this route, because the resulting models automatically guarantee realizability. Some new stochastic Lagrangian models are presented that correspond (either exactly or approximately) to popular Reynolds‐stress models.

This publication has 20 references indexed in Scilit: