Natural dispersion of aerosols, particles and pollutants: the role of turbulent fluctuations

• Grant number: 20/06273-2
• Support Opportunities: Regular Research Grants
• Start date: January 01, 2021
• End date: June 30, 2023
• Field of knowledge: Engineering - Mechanical Engineering - Transport Phenomena
• Agreement: Université de Lyon (UDL)
• Principal Investigator: Gustavo Carlos Buscaglia
• Grantee: Gustavo Carlos Buscaglia
• Principal researcher abroad: Mickaël Bourgoin
• Institution abroad: Laboratoire de Physique, France
• Host Institution: Instituto de Ciências Matemáticas e de Computação (ICMC). Universidade de São Paulo (USP). São Carlos , SP, Brazil
• Associated researchers: Livia Souza Freire Grion

Abstract

Potential sources of hazardous pollutants are numerous. In natural systems we can mention volcano eruptions, sand and dust storms, toxic gas emission from volcanic lakes, sediments deposition in estuaries, etc. In the human category, origins of aerosol and pollutants range from everyday pollution (industry, transports, etc.) and human emitted particles (sneezing, coughing) to real catastrophes on human facilities (chemical plants, nuclear plants, etc.) triggered by natural events or accidents. Beyond the local consequences, such events often end in global crisis as the locally emitted pollutants are spread and dispersed at large scales by the turbulent flow into which they are carried. A proper handling of such crisis requires the capacity to accurately model the dispersion processes. The recent Covid19 pandemics, which has been shown in particular to propagate via airborne particles, is a fresh example illustrating the crucial importance of the turbulent transport of particles.The present proposal addresses the mechanisms by which pollutants and aerosols are spread from local emitting sources, sometimes up to planetary scale, due to turbulence in atmospheric, marine or fluvial environments. More precisely, by combining experiments, simulations and mathematical approaches, we aim at improving our understanding of the physical mechanisms and interplay of turbulent relative dispersion and preferential concentration. These are important mechanisms leading to strong, either temporary or persistent, inhomogeneities and fluctuations of particles distribution which make real hazard predictions extremely complex.Our consortium gathers Brazilian and French experts with complementary skills regarding the methods (experiments/numerics/mathematics) and the frameworks (model systems, atmospheric and oceanic flows) which warrant results and relevant applications from the proposed studies. (AU)