A simple analytical solution for the complete spatial concentration distribution in laminar open channel flow

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Zi Wu, X.D. Fu, G.Q. Wang, L. Shao

Wednesday 1 july 2015

12:42 - 12:45h at Asia (level 0)

Themes: (T) Hydro-environment, (ST) Impacts of pollutants on the water environment, Poster pitches

Parallel session: Poster pitches: 9G. Environment - Impact

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For the concept of Taylor dispersion, instead of focusing only on the cross-sectional mean concentration, recent research interest has been raised also for the transverse concentration distribution (Wu and Chen, 2014. J. Fluid Mech., 740, 196-213). Such detailed information is important for understanding the impacts of pollutants on water environment. In this paper, a simple analytical solution for the evolution of the complete spatial concentration distribution is presented for an instantaneous pollutant release in the laminar open channel flow. The result is verified in comparing with the previously obtained analytical solution by the two-scale perturbation analysis, showing that the present solution can give a good estimation for the complete spatial concentration distribution when the Taylor dispersion model is applicable. Thus the analytical solution is useful for analyzing the slow-decaying transient effect, which characterizes the decaying of the transverse concentration difference.