Modélisation du captage des polluants lors des opérations de meulage

Abstract : This study based at the same time in experimental and numerical aspect, is part of the framework to understand deeply the capture of pollutants on rotating machines and focuses especially on the characterization of the dispersion of fine particles generated by machining operations : i.e. these particles are assimilated as a passive tracer due to their negligible aerodynamic response time. The main objective covered by this study is to develop a numerical method of close capture exhausts systems for machining devices. The first task was to achieve an experimental device re-creating a similar grinding operation in a perfectly controlled environment. The flow used is defined as the one generated by a rotating cylinder in a ventilated test rig. A pollutant of particles, represented by spherical glass beads, is produced inside the test rig (by using a seeding system of particles), recreating therefore the aerodynamic effects of largest machining particles. A tracer gas, representing the fraction of fine particles, is injected simultaneously with the jet of particles through a capillary tube placed at the source. The properties of the jet of particles obtained are characterized by particle tracking velocimetry (PTV) allowing then to obtain data input and validation of numerical simulations. This particle tracking technic, developed in this study remains as robust method even in heavily loaded particles (i.e. the source region of the jet). The velocity field of the gas phase has meanwhile been characterized by particle image velocimetry (PIV), using a code developed specifically for this assay (Belut 2006 [4]). The dispersion of a tracer gas (sulfur hexafluoride - SF6) emitted simultaneously with the jet of particles is then studied experimentally : the dispersion of such a gas is indeed considered representative of finest particles which aerodynamic response time is negligible. Finally, a complete modeling of the experimental test rig is performed to allow comparison with experimental results in order to progress in the validation of models used to describe the dispersion of a tracer gas representative of finest particles. The commercial soft ware FLUENT is used for numerical simulations
Complete list of metadatas

Cited literature [66 references]  Display  Hide  Download

https://hal.univ-lorraine.fr/tel-01749601
Contributor : Thèses Ul <>
Submitted on : Thursday, March 29, 2018 - 12:20:54 PM
Last modification on : Wednesday, April 11, 2018 - 1:27:50 AM
Long-term archiving on : Friday, September 14, 2018 - 7:57:22 AM

File

DDOC_T_2012_0185_TAFNOUT.pdf
Files produced by the author(s)

Identifiers

  • HAL Id : tel-01749601, version 1

Collections

Citation

Fatna Tafnout. Modélisation du captage des polluants lors des opérations de meulage. Autre. Université de Lorraine, 2012. Français. ⟨NNT : 2012LORR0185⟩. ⟨tel-01749601⟩

Share

Metrics

Record views

18

Files downloads

23