The Simultaneous Occurrence of Logarithmic and S-Shaped Velocity Profiles in Gravel-Bed River Flows

• Autorzy: Franca M. J. , Lemmin U.
• Języki publikacji: EN

Abstrakty

EN

Based on Acoustic Doppler Velocity Profiler (ADVP) field measurements, we discuss velocity profiles observed in two shallow gravel-bed rivers with low relative submergence. In these flows, log-shaped profiles and s-shaped profiles simultaneously exist, indicating the possibility of 3D flow inside the roughness layer. A quasi-2D layer is generally found in an intermediate region of the flow above the roughness layer. Therefore a best-fit log-law approach may lead to estimates of a roughness parameter which are reasonably correlated with the local flow resistance. However, above a certain limit of the ratio roughness/water depth (∼0.6 from our measurements), the velocity distribution in the lower regions predominantly corresponds to an s-shaped profile.

Słowa kluczowe

EN

field measurements; gravel-bed river flows; velocity profiles

• Wydawca: Institute of Hydro-Engineering of Polish Academy of Sciences
• Czasopismo: Archives of Hydro-Engineering and Environmental Mechanics
• Rocznik: 2009
• Tom: Vol. 56, nr 1-2
• Strony: 29--41
• Opis fizyczny: Bibliogr. 21 poz., il.

Twórcy

autor

Franca M. J.

autor

Lemmin U.

• FCT - New University of Lisbon and IMAR-CMA (Un. Coimbra) Quinta da Torre, 2829-516 Caparica, Portugal,

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