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Inlet effects on roll-wave development in shallow turbulent open-channel flows

Authors :
Francesca Campomaggiore
Andrea Vacca
Michele Iervolino
Cristiana Di Cristo
Campomaggiore, Francesca
DI CRISTO, Cristiana
Iervolino, Michele
Vacca, Andrea
Francesca, Campomaggiore
Cristiana, Di Cristo
Cristiana Di, Cristo
Michele, Iervolino
Andrea, Vacca
Source :
Journal of Hydrology and Hydromechanics, Vol 64, Iss 1, Pp 45-55 (2016)
Publication Year :
2016
Publisher :
Institute of Hydrology of the Slovak Academy of Sciences and the Institute of Hydrodynamics of the Academy of Sciences of the Czech Republic, 2016.

Abstract

The present work investigates the effect of the flow profile induced by an inlet condition on the roll-wave evolution in turbulent clear-water flows. The study employs theoretical and numerical analyses. Firstly, the influence of the inlet condition on the spatial evolution of a single perturbation in a hypercritical flow is examined through the expansion near a wavefront analysis. The results show that an accelerated unperturbed profile reduces the disturbance spatial growth. A decelerated profile causes an increase. The effect of the flow profile on the spatial evolution of roll-wave trains is then numerically investigated solving the Saint Venant equations with a second-order Runge-Kutta Total Variation Diminishing (TVD) Finite Volume scheme. The numerical simulations comply with the analytical results for the initial and transition phases of the roll-wave development. The unperturbed profile influences even the roll-waves statistical characteristics in the final stage, with a more evident effect in case of accelerated profiles. The influence of the flow profile should be therefore accounted for in the formulation of predictive criteria for roll-waves appearance based on the estimation of the disturbance spatial growth rate.

Details

Database :
OpenAIRE
Journal :
Journal of Hydrology and Hydromechanics, Vol 64, Iss 1, Pp 45-55 (2016)
Accession number :
edsair.doi.dedup.....cd6397f8aec77e2deb1e3edc5744bdb9