Scaling laws for centrifuge modelling of soil transport by turbulent fluid flows

Abstract

The interaction between turbulent fluid flow and soil particles in local erosion processes is relevant to a number of problems in geotechnical engineering. Physical modelling of these problems at elevated gravities in a centrifuge can increase our understanding of these complex processes and provide validation and calibration for numerical analyses. The correct reproduction of the prototype behaviour requires the scale model to be constructed according to the appropriate scaling laws. Traditionally, the transport behaviour of soil particles has been studied in hydraulic laboratory models, with little consideration of the soil body and the effect it has on the observed transport. In this paper the scaling laws required for studying dynamic behaviour of soil particles associated with fluid motions using the technique of centrifuge modelling have been considered using particle mobility conditions and relative fall velocity criterion. The viability of modelling problems that involve both fluid dynamics and geotechnical processes is discussed. The study indicates that combined sediment transport and subsoil processes can be modelled using centrifugation subject to a number of limitations.