Multiphase Spray Simulation in an Axisymmetric Jet
Abstract
The motions of spherical particles in a turbulent spray are simulated numerically using a three-dimensional joint Eulerian-Lagrangian simulation technique. One-way coupling is assumed between the particle and the continuous flow field, with no particle-particle interactions. The instantaneous fluid velocity and velocity gradient of the continuous phase is simulated with the use of an advanced Navier-Stokes based Lagrangian PDF (probability density function) stochastic model. The mean fluid velocity field is obtained with the use of the Reynolds stress transport model of the FLUENT computer code. The spray of spherical droplets is modeled as a series of continuously injected spheres whose motions are described by a modified BBO (Basset Boussinesq Oseen) equation, consisting of the nonlinear Stokes drag, a three-dimensional modification of the Saffman lift, and gravity. Multiple particle trajectories are then numerically evaluated by integrating the equations of motion using the computed fluid velocity field as input. Ensembles of particle trajectories are generated for a point and line source emanating near the inlet to the spray chamber. Test cases for axisymmetric and plane jets are considered. The particles are injected at a velocity on the order of the mean streamwise velocity. Interactions between particles and the given shear flows are examined for a range of Stokes numbers. Analysis of particle dispersion yields results which are consistent with previous investigations for particle trajectories in free shear flows, where maximum dispersion is found for Stokes numbers of order unity.
- Publication:
-
APS Division of Fluid Dynamics Meeting Abstracts
- Pub Date:
- November 2000
- Bibcode:
- 2000APS..DFD.DL002S