A SECOND-ORDER MOMENT TWO-PHASE TURBULENCE MODEL BASED ON THE LAGRANGIAN PDF

Using the Lagrangian analysis of particle motion and PDF(Probability Density Distribution Function) method,an improved the second-order-moment model of particle-phase is proposed.Based on the Lagrangian stochastic two-phase motion equations, using the stochastic-process analysis and the signal-system analysis, the obtained particle-phase PDF transport equation,the two-fluid model equations and the basic version of two-phase fluctuation velocity correlation are in agreement with those obtained by other investigators.However,significant improvement is made for the closure model.The crossing-trajectory effect,continuity effect,inertia effect and the anisotropic turbulence have been taken into account to simulate the interaction time between the particle and the fluid turbulence seen by the particles.