Numerical study of evaporating sessile droplets and corrosion

Abstract

International audienceIn France, some of nuclear wastes are packaged in stainless steel containers and stored in above-ground storage facilities. These waste packages are likely to remain in interim storage for a periodof several decades before being moved to an underground facility for permanent disposal. During theinterim period of storage, atmospheric aerosols will deposit on the container surfaces, in particularin marine atmosphere, where sprayed droplets are carried by the wind from the sea. The dropletdeposits on the exposed surface and becomes saline sessile droplet. This creates an electrolyte offinite size that can react with the metallic surface, leading to an atmospheric corrosion phenomenon.Moreover, the day/night cycles induce a variation of the relative humidity and the temperature: thisleads to a constant repetition of evaporation and condensation phases which can increase the corrosionphenomena [1].The aim of the study is to enrich and develop a numerical analysis of the corrosion under droplet, soas to accurately predict its impact on the lifetime of the materials. We propose a numerical modelof evaporation dynamics of salty sessile drops, built with Basilisk, a free software which implementsfinite volume methods for the Navier-Stokes equations [2]. Our numerical results will be validate withlitterature and experimental data