Yann Gregoire Email and Phone Number

INERIS performs research and expertise activities requested by the public authorities and industrials. It includes teams of engineers, chemists, physicians, doctors, ecotoxicologists, veterinarians, economists, statisticians, and specialists in risk assessment; about 600 people including engineers and researchers. Located in Verneuil-en-Halatte (Oise), INERIS works on experimental approach, modelling, methodological approach of risks, and also on experience feedback for a better comprehension of phenomena at the origin of risks.Particularly, INERIS is equipped with small and real scale experimental facilities among the largest in France. Risk methodology, numerical modelling, experimental works and industrial feedback are combined to obtain a better understanding on the risks origins.

The Shock Wave Physics Group (SWPG) at McGill University is directed by Prof. J. H. S. Lee and has a long history of the study of high-speed turbulent deflagration and detonation phenomena. Current research work includes the initiation of detonation, the transition from deflagration to detonation, detonation propagation in nonideal heterogeneous condensed-phase explosives, and combustion synthesis and dust combustion in microgravity.

EXPERIMENTAL AND NUMERICAL STUDY ON THE EXPLOSIVE DISPERSION AND COMBUSTION OF METAL PARTICLESLes domaines de compétences du LCD reposent sur des études expérimentales, théoriques et numériques, des aspects énergétiques, physiques et chimiques de la combustion. Ses activités se répartissent selon cinq axes : phénomènes de flamme et combustion supersonique, détonations et combustion subsonique, chimie de la combustion et combustion des solides, écoulement et combustion dans les milieux diphasiques et ondes de choc (propagation dans les solides et transferts dans les milieux poreux). Le LCD résout les problèmes posés dans les domaines de la propulsion, de la sécurité des procédés et installations industriels, ainsi que la protection de l’environnement.

EXPERIMENTAL AND NUMERICAL STUDY ON THE EXPLOSIVE DISPERSION AND COMBUSTION OF METAL PARTICLESSummary:The explosive dispersion of particles and their inflammation in air along with the blast wave effectswere investigated experimentally and numerically. The experimental configuration consisted in studying the free-field explosion of spherical charges made of a central booster of solid explosive surrounded by a loose-packed density shell of inert (glass spheres) or reactive (atomized and flaked aluminium) particles. The high speed cinematography of the explosions coupled with image processing by a "Background Oriented Schlieren" method, and the pressure records by piezoelectric gauges permit to plot the x-t diagrams of the explosions. A technique has been developed to capture samples of dispersed particles and to make their post-analysis. The experimental results are confronted with numerical simulations performed with LCD’s reactive multiphase flows code EFAE. The boundary of the dispersed cloud is not uniform but has a spiky shape with dendrites due to theformation of particle agglomerates of several millimetres. After 1m of propagation, some of those agglomerates overcome the leading shock front due to a ballistic effect. Glass particles are disintegrated by the shock. They have a mitigating effect, making the shock propagation slower and decreasing its amplitude. The effect of aluminium particles depends on their size: with the finer ones, after an initial slowdown phase, a re-acceleration of the leading shock and an increase of the pressure impulse are observed. With coarser particles, the shock is weakened but particle combustion raises the pressure level behind the shock front and slightly increases its impulse. An analysis of the collected agglomerates reveals that, in all cases, the combustion of aluminium particles is incomplete. Numerical simulations are in reasonable agreement with experimental results in the farfield domain.

Project: Study on the influence of the granulometry of aluminium particles on the explosion of enhanced blast explosives.The French-German Research Institute of Saint-Louis is a binational research institute established by the Federal Republic of Germany and the French Republic on the basis of a treaty signed in 1958. The core mission of ISL is: "Research, scientific studies and basic predevelopment in the field of defense and security".The classical working areas of ISL include: laser-matter interaction, laser development, detonics, perforation, protection, ballistics, the environment and protection of the soldier, acoustics, power electronics, high-power microwaves, aerodynamics and flight mechanics, optronics, sensors.Recently ISL has reinforced its activities on issues of civil security and countermeasures against terrorism encountered both at home and during overseas military operations.The institute is situated in Southern Alsace near the German and Swiss borders.

Project: Comparison of the «I/O ratios of PM2.5» in Hong Kong and validation of an air purifying system (7 weeks)Air Pollution Laboratory:The prosperity of Hong Kong gives us a high standard of living but, at the same time, brings us many environmental problems. Most pollution is caused by the production of power and consumption of energy such as in electric power plants and running vehicles. The construction of infrastructure also produces many problems which require solutions by environmental engineers. The Environmental Impact Assessment Ordinance requires all major engineering projects be assessed in all environmental aspects before their commencement. Consequently, our society requires a large number of mechanical engineers who possess the knowledge in various modern energy production and conversion systems, as well as environmental awareness. Environmental engineering is a broad area and this feature is wee-reflected in the offered courses. They cover concepts and measurements of water and air quality, air pollution control, municipal and industrial wastewater treatment, solid and hazardous wastes, noise management etc.