A turbulent model for gas-particle jets

This work is concerned with turbulent diffusion in gas-particle flows. The cases studied correspond to dilute flow and small Stokes number, this impli es that the mean velocity of the particles is very similar to that of the f luid element. The classical k - epsilon method is used to model the gas-pha se, modified with additional terms for k and epsilon equations, that takes into account the effect of particles on the carrier phase. The additional d issipation term included in the equation for k is due to the slip between p hases at an intermediate scale, far from both the Kolmogorov and the integr al scales. This term has a proportionality constant equal to 3/2 of Kolmogo rov constant, C-0. In this paper, a value of 3.0 has been used for this con stant as suggested by Du et al., 1995. "Estimation of the Kolmogorov Consta nt C-0 for the Langarian Structure Using a Second-Order Lagrangian Model of Grid Turbulence,'' Phys. Fluids 7, (12), pp. 3083-3090. The additional sou rce term for the epsilon equation is taken as proportional to epsilon /k, a s is usually done. In all experiments analyzed the particles increased the dissipation of turbulent kinetic energy. A comparison is made between the r esults obtained with the model proposed in this work and the experiments of Shuen et al., 1985, ''Structure of Particle-Laden Jets: Measurements and P redictions,'' AIAA Journal, 23, No. 3, and Hishida et al., 1992, ''Experime nts on Particle Dispersion in a Turbulent Mixing Layer." ASME Journal of Fl uids Engineering, 119, pp. 181-194. [S0098-2202(00)02103-9].