| Title: |
Numerical simulation and physical analysis of the dispersion of charged inertial particles transported by stationary homogeneous isotropic turbulence |
| Authors: |
Boutsikakis, Athanasios |
| Contributors: |
Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE) |
| Publication Year: |
2020 |
| Collection: |
OATAO (Open Archive Toulouse Archive Ouverte - Université de Toulouse) |
| Subject Terms: |
Electrostatic interaction; Interaction particule-turbulence; Théorie de Tchen-Hinze; Dispersion; Concentration préférentielle |
| Description: |
In this work, we study by numerical simulation the effect of electric charges on the dispersion of particles transported by a turbulent flow. The Navier-Stokes equations are solved by Direct Numerical Simulations (spectral approach) coupled with a Lagrangian solver in order to calculate the trajectories of each particle. A stochastic forcing scheme allows to obtain statistically homogeneous, isotropic and stationary turbulent flows. In the thesis, an original method to take into account electrostatic forces has been developed and validated on elementary configurations. In this method, the short-range interactions are estimated via a sum of the inter-particle interactions inside a cut-off distance and the long-range ones via a sum of interactions of particles with groups of particles which, at a distance greater than the cut-off distance, are considered as pseudo-particles. The convergence, the precision and the computational cost of the method have been studied in detail for its implementation for tri-periodic domains. The ensemble of these developments has been carried out in a parallel code which allows to perform simulations on a supercomputer of gas-particle flows containing up to $2\times 10^5$ particles. Firstly, the analysis of dry granular flows allowed to define a characteristic time scale of the effect of electric charges and to link it to the physical properties of the particles, in particular their diameter and agitation. The mechanism of transformation of the electric potential energy into particle kinetic energy is analyzed according to this time scale. Secondly, simulations of homogeneous isotropic turbulence transporting like-charged particles were carried out by varying their diameter (dynamic Stokes number) and their charge (electrostatic Stokes number). The simulations show that, for a given dynamic Stokes, the increase in particle charge leads to a decrease in their agitation since the electrostatic (repulsive) forces are conservative. The detailed analysis shows that, in fact, the ... |
| Document Type: |
thesis |
| File Description: |
application/pdf |
| Language: |
English |
| Relation: |
https://oatao.univ-toulouse.fr/28879/1/Boutsikakis_Athanasios.pdf; Boutsikakis, Athanasios. Numerical simulation and physical analysis of the dispersion of charged inertial particles transported by stationary homogeneous isotropic turbulence. PhD, Dynamique des fluides, Institut National Polytechnique de Toulouse, 2020, 162 p. |
| Availability: |
https://oatao.univ-toulouse.fr/28879/ |
| Rights: |
info:eu-repo/semantics/openAccess |
| Accession Number: |
edsbas.2CCE746E |
| Database: |
BASE |