Probability density function and Reynolds-stress modeling of near-wall turbulent flows

Probability density function (pdf) methods are extended to include modeling of wall-bounded turbulent flows. A pdf near-wall model is developed in which the generalized Langevin model is combined with an exact model for viscous transport. Then the method of elliptic relaxation is used in incorporate the wall effects without the use of wall functions or damping functions. Information about the proximity of the wall is provided only in the boundary conditions so that the model can be implemented without ad hoc assumptions about the geometry of the flow. A Reynolds-stress closure is derived from this pdf model, and its predictions are compared with DNS and experimental results for fully developed turbulent channel flow. (C) 1997 American Institute of Physics.