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Comments on «Modeling stratified suspension concentration distribution in turbulent flow using fractional advection–diffusion equation» by Snehasis Kundu, environmental fluid mechanics, https://doi.org/10.1007/s10652-019–09,679-9

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Abstract

In a paper published in Environmental Fluid Mechanics, Kundu proposed an interesting study about modeling suspended sediment concentrations profiles in turbulent open-channel flows. The used model is based on fractional advection–diffusion equation and incorporates the effects of non-local transport of particles, stratification, hindered settling velocity and damping of mixing length. Kundu’s model needs vertical profiles for mixing velocity and mixing length. Despite the interest, the study shows a weakness about Kundu’s choice of these two parameters and a related contradiction. Due to this shortcoming, the proposed model of sediment diffusivity is questionable. In this note, the weakness is pointed out. We comment on the choice of Kundu of these two parameters which are in contradiction with the used parabolic neutral eddy viscosity profile. We show that velocity profiles obtained from an eddy viscosity based on Kundu’s parameters are inaccurate. The mixing velocity and the model of sediment diffusivity are corrected and improved eddy viscosity formulations are presented.

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  1. ECAM-EPMI - Ecole Supérieure d’Ingénieurs en Génie Electrique, Productique et Management Industriel, LR2E-Lab, Quartz-Lab (EA 7393), 13 Boulevard de l’Hautil, 95092, Cergy-Pontoise, France

    Rafik Absi

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  1. Rafik Absi
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Absi, R. Comments on «Modeling stratified suspension concentration distribution in turbulent flow using fractional advection–diffusion equation» by Snehasis Kundu, environmental fluid mechanics, https://doi.org/10.1007/s10652-019–09,679-9. Environ Fluid Mech 21, 1189–1196 (2021). https://doi.org/10.1007/s10652-021-09821-6

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