An Assessment of Particle Characteristics for the Analysis of Wind Turbulence Generated Gas Transport
Gas flow through porous media is an important process for engineers to assess as a part of the design process. It can be modelled physically and numerically. Hazardous gases ranging from flammable vapours to radioactive gases can migrate through soil and are a concern on contaminated sites. Wind turbulence, which can be caused by the presence of man-made structures, can generate 20–70 times the amount of gas dispersion compared to calm conditions. The extent and rate of gas flow through a soil medium is dependent on the properties of the soil, including particle characteristics and the boundary conditions of the soil which includes flow rate and turbulence (gustiness). Such boundary effects may be strongly influenced by local site conditions. The important particle characteristics for gas flow through soils include primarily particle size, with minor contributions from shape and roughness. Many standardised methods for particle size measurement assume that the particles are spherical and so become much less accurate for elongate and irregular particles. Imaging techniques in combination with computational analysis allow more accurate quantification. An analysis of particle shape in two and three dimensions has been undertaken allowing the measurement of particle size and roughness. This can be used to inform models of soil behaviour. The data from this analysis includes roughness measurements from 453 particles. This data is available on request.
KeywordsGas flow Porous media Particle analysis Soil characterisation Vapour intrusion
- Hazen, A.: Discussion: dams on sand foundations. Trans. Am. Soc. Civ. Eng. 73, 199 (1911)Google Scholar