Turbulent Mixing with a Focus on Dependency on Stokes Number
This study addresses particulate dispersion in a spatially developing mixing layer.
Goals of the Study
Some details of the computed vortex structure are described including the development of streamwise counter-rotating vortices in the braid regions, their effect upon spanwise rollers and the breakdown of the flow into turbulence. Particle dispersion in the mixing layer flow is examined including the effects of streamwise vorticity and one-way and two-way coupling between phases.
Simulations
Linear growth in momentum thickness
Reynolds stresses and vorticity thickness
Particle Dispersion in a spatially developing 3D Mixing Layer
Parameter – Stokes number
Solid particles, 1-way or 2-way particle-fluid interactions computed
• St = 0.001 (Light particles)
• St = 4
St = 100 (Heavy particles)
Particle Dispersion with One-way Coupling
St = 0.001
St = 100
St = 4
St = 100
Two-way Coupling
Vortical elements generated and added to the flow due to 2-way coupling are colored in pink.
Mean Velocity
Reynold stresses
Momentum Thickness
Conclusions
Numerical simulation of a spatially developing 3D mixing layer including particle dispersion has been carried out using the VorCat implementation of the vortex method. Both the vortical structure of the computed mixing layer and the properties of particle dispersion with one-way coupling show much agreement with prior work. This approach was also seen to provide novel insights into the flow mechanisms that can be of considerable value in practical applications. Detailed descriptions of all aspects of this work will be provided in subsequent publications.