On particles laden airflows around moving parts: application to close capture exhaust systems for machining tools (French PhD)

The aim of this work is to contribute to the development of a new design method for close capture exhaust systems for machining pollutants, based on the numerical simulation of particles-laden airflows induced by rotating tools.
Firstly, using numerical experiments and bibliography, we demonstrate the feasibility and interest of using large Eddy simulation, coarsely resolved in the near-wall region (or VLES standing for Very Large Eddy Simulation), coupled with lagrangian tracking of particles, to model machining induced two-phase flows, and accurately reproduce particles-turbulence interaction.
Secondly, we definitively validate the selected models using the extensive experimental data collected on an original test-rig, recreating a pseudo machining operation. In this experimental device, a stable particle stream with a controlled flow rate is obtained by pushing spherical glass particles in a pipe against a rotating cylinder. The jet of particles in the test-rig is characterized using phase Doppler particles analyser (PDPA), and the airflow properties are measured thanks to particle image velocimetry (PIV), this last technique requiring the development of a specific code in order to discriminate the two phases involved.
The comparison between measurements and simulations opens new prospects concerning the industrial use of large eddy simulation applied to multiphase flows.