Computation of Particle Laden Turbulent gas Jet Flows Employing the Stochastic Separated Flow Approach

Abstract

The dispersion of particles in the presence of Turbulent gas flow is studied theoretically using a stochastic separated flow model and the results compared with the available experimental data. As the particle loading in the jet is of the order of 0.1-0.4 per cent, the particles are assumed to have negligible effect on the mean and the turbulent gas phase properties (one-way coupling). The particle-turbulent eddy interactions are calculated by paying attention to the energy containing eddies, characterised by the integral length scale. The fluctuating velocities are sampled randomly from Gaussian distribution, and the particle trajectories are obtained using a procedure similar to random-walk computation. A large number of particle trajectories are averaged to obtain the statistical nature of the turbulent gas-particle jet. It is seen that the particles with less inertia, which are characterised by the Stokes number, tend to diffuse more. The turbulent diffusivities of the particles are in agreement with the available experimental data, when the time-averaged velocities of gas and particles are the same, obtained by the stochastic separated flow model.