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Full-Text Articles in Environmental Engineering
Laboratory Measurements Of Differential Diffusion In A Diffusively Stable, Turbulent Flow, P. Ryan Jackson, Chris R. Rehmann
Laboratory Measurements Of Differential Diffusion In A Diffusively Stable, Turbulent Flow, P. Ryan Jackson, Chris R. Rehmann
Chris R. Rehmann
Laboratory experiments were performed to determine the conditions under which differential diffusion occurs and to evaluate its effect on the mixing efficiency. Diffusively stable profiles of temperature and salinity were stirred steadily by horizontally oscillating vertical rods. The two-component stratification ensures that both scalars experience the same stratification and forcing, or Richardson and Reynolds numbers. The eddy diffusivities KT and KS, for temperature and salinity, were estimated by fitting theoretical solutions of diffusion equations to measured profiles, and the mixing efficiency was computed as the ratio of the potential energy change during a stirring interval to the work done in …
Kinematic Effects Of Differential Transport On Mixing Efficiency In A Diffusively Stable, Turbulent Flow, P. Ryan Jackson, Chris R. Rehmann
Kinematic Effects Of Differential Transport On Mixing Efficiency In A Diffusively Stable, Turbulent Flow, P. Ryan Jackson, Chris R. Rehmann
Chris R. Rehmann
If temperature and salinity are mixed at different rates, the mixing efficiencies in flows with the same stratification and forcing can vary if the contributions of temperature and salinity to the density differ. Two models are used to examine the effect of differential transport of salt and heat on the mixing efficiency. The first model assumes constant eddy diffusivities for heat and salt and examines the effect of the density ratio Rρ = αΔT/βΔS and the diffusivity ratio d = KS/KT on the mixing efficiency. The model predicts that the effect of differential transport can be as large as that …