Numerical Simulation Of Particle-laden Swirling Jet With LES/FDF Model

Particle-laden Swirling jet is usually met in the swirling burner which has been widely used in many power stations. It has become one of the great interest for many researchers in the field of gas-particle multiphase flow.An LES/FDF model of two-phase flow was developed, in which a filtered density function (FDF) transport was derived for the fluid velocity seen by the particles in gas-particle two-phase flow based on the large eddy simulation(LES) for the fluid phase.,A new search algorithm for particles in gas-particle two-phase flow was developed to locate particles on unstructured grids. A set of structured index grids was constructed on the flow field first, and then the unstructured grids were related to the structured index grids. The particles can be located in the flow field by way of being searched on the index grids. This method can be easily realized and obviously improve the efficiency.A particle-laden Swirling jet was numerically investigated with the developed LES/FDF model. The mean velocity and the fluctuating velocity of the particle phase were both compared to the experiment and the simulation results without using the FDF model, the results sow that the FDF model can well describe both the time-average field and fluctuating velocity of the particle phase and the influence of sub-grid scale(SGS) eddies can be well described by the model. Numerical investigations on velocity change of particles with gas flow field was also carried out. Different particle diameters were adopted for different cases. The results show that the decayed rate of streamwise velocity due to the recirculation zone of the gas flow can apparently influence the distribution of the particle velocity. The streamwise particle velocity decreases along the axis more rapidly as the particle diameter decreases.