A simple Lagrangian PDF model for wall-bounded turbulent flows

Abstract

A simple Lagrangian pdf model is proposed with a new numerical algorithm for application in wall-bounded turbulent flows. To investigate the performance of the Lagrangian model, we minimize model's dependence on empirical constants by selecting the simplest model for turbulent dissipation rate. The effect of viscosity is also included by adding a Brownian random walk calculate the position of a particle. For the no-slip condition at the wall and correct near-wall behavior of velocity, we develop a new boundary treatment for the particles that strike the wall. By applying the model to a fully developed turbulent channel flow at low Reynolds number, we investigate the model's performance through comparison with direct numerical simulation result.