Holistic model for atmospheric corrosion Part 5 – Factors controlling deposition of salt aerosol on candles, plates and buildings

Abstract

This paper is the fifth in a series of papers outlining a holistic model of atmospheric corrosion. Previous papers have outlined how the airborne salinity could be estimated at any given location. This paper presents a theoretical analysis of aerosol/particulate deposition, in conjunction with computational fluid dynamics (CFD) studies. Theoretical and CFD studies address whether salt aerosol/particulate deposition is controlled by mean winds, wind turbulence or Brownian motion (deposition of salt via rain/fog etc. is not considered in this paper). Analysis indicates that deposition due to wind turbulence is the dominant mechanism for marine aerosol, and that other deposition modes can be effectively ignored. Given this, further studies are presented for salt candles, plates and buildings. From these studies, approximations are derived so that salt deposition on exposure plates and on buildings can be estimated from measurements from ISO salt candles.