A novel method measuring the clustering of particles: Pseudo-gravitation

Abstract

A novel pseudo-gravitation method is proposed to quantitatively measure the degree of the preferential concentration of particles in turbulent flows, where virtual gravitations are employed to evaluate the extent of particle accumulation. The pseudo-gravitation method introduces a nondimensional “Gravitation Index” (GĨ) to estimate the local concentration of particles and a nondimensional “Global Gravitation Index” (GGĨ) to quantify the degree of particle clustering across the whole domain. This method can effectively characterize both the Eulerian and Lagrangian properties of the particle preferential concentration, without the need for any predefined artificial parameters. Additionally, it is not only robust to the variation in the number of particles but also sensitive to the change in physical parameters, such as the Stokes number (St) and Reynolds number (Re).