Comparison of Particle Tracking Methods in Large Eddy Simulations and Direct Numerical Simulations

Nanoparticles are found in many useful products, such as sun protection creams, wood preservatives, and tires. However, nanoparticles can have several undesirable characteristics as well. For example, the combustion of hydrocarbons can produce nanoparticles which cause health problems and adversely affect the environment. Because of these deleterious effects, it is important to track them in numerical simulations for predictive modeling. There are two main methods to track particles as they move through a flow field. The first is the Lagrangian approach, in which the motion of each individual particle is tracked. The second is the Eulerian approach, in which the particle phase is treated as a continuum. In terms of flow physics, Direct Numerical Simulations (DNS) are the most accurate, but due to their high computational cost, Large Eddy Simulations (LES) are often used instead as a compromise between accuracy and efficiency. Although there are studies regarding the particle tracking and fluid simulation methods separately, there is still a lack of a comprehensive study on the combination of the two areas. In this work, DNS and LES are conducted on a cube of homogeneous isotropic turbulence with particles tracked using both the Lagrangian and Eulerian methods. Special attention will be paid to the effect of the LES filtering on the transport of the particles.