Mean flow characteristics in a flat and eroded bed curved channel

• Autorzy: Sumiadi Sumiadi , Abduh Moh

Identyfikatory

DOI

10.24425/jwld.2022.140794

• Języki publikacji: EN

Abstrakty

EN

The mean flow characteristics in a curved channel are really different from those in a straight channel. The main cause is the existence of secondary flow within the flow in the curved channel. This paper will discuss the differences in mean flow characteristics due to changes in the bed topography in the curved channel. Acoustic Doppler Velocimetry (ADV) measurements have helped to analyse characteristics of the mean flow on flat and eroded beds in a 180° curved channel. Sand (mean diameter d₅₀ = 0.001 m and specific gravity Gs = 2.65) was selected as the bed material. The condition of flow in the approach section was steady and uniform with 0.159 m depth. One of the mean flow characteristics in the curved channel is the free surface superelevation due to the presence of centrifugal force. The second is the circular motion toward the inner-bank region at the lower layer and toward the upper layer outer-bank region. The cause of the circulation is the difference in centrifugal forces between the two layers. The magnitude of velocity near the bed surface is more significant than the flow near the water surface. This causes erosion in the outer bank region and deposition in the inner bank region. In general, tangential velocity v_θ in flat bed is greater than its tangential velocity in eroded bed. The maximum velocity path in a flat and eroded bed of the curved channel resembles a sinusoidal curve, where the minimum value is located at 90° and 120° of the curve.

Słowa kluczowe

EN

curved channel; eroded bed; flat bed; mean flow

• Wydawca: Wydawnictwo ITP
• Czasopismo: Journal of Water and Land Development
• Rocznik: 2022
• Tom: no. 53
• Strony: 170--175
• Opis fizyczny: Bibliogr. 14 poz., rys., wykr.

Twórcy

autor

Sumiadi Sumiadi

• University of Brawijaya, Jl. Veteran, Ketawanggede, Malang 65145, Indonesia

• https://orcid.org/0000-0001-7620-1878

autor

Abduh Moh

• Universitas Muhammadiyah Malang, Malang, Indonesia

• https://orcid.org/0000-0002-1831-381X

Bibliografia

• BLANCKAERT K. 2003. Flow and turbulence in sharp open-channel bends. PhD Thesis. No. 2545. Lausanne. Switzerland Ecole Polytechnique Federale pp. 286. DOI 10.5075/epfl-thesis-2545.
• GARCÍA C.M., CANTERO M.I., NIÑO Y. GARCÍA M.H. 2004. Acoustic Doppler Velocimeters (ADV) Performance Curves (APCs) sampling the flow turbulence. World Water and Environmental Resources Congress. DOI 10.1061/40737(2004)294.
• GONZALEZ J.A., MELCHING CH., OBERG K.A. 1996. Analysis of open-channel velocity measurements collected with an Acoustic Doppler Current Profiler. Proceedings from the 1st International Conference on New/Emerging Concepts for Rivers. 22–26.09.1996 Chicago. DOI 10.1061/40517(2000)308.
• JEONG J.W., YOON S.E. 1998. An experimental study on the characteristics of flow and bed topography with changing bed material in a curved channel. Journal of Korea Water Resources Association. Vol. 31. Iss. 3 p. 291–301.
• KIKKAWA H., IKEDA S., OHKAWA H., KAWAMURA Y. 1973. Secondary flow in a bend of turbulent stream. Proceedings of the Japan Society of Civil Engineers. No. 219 p. 107–114.
• ODGAARG A.J., 1984. Flow and bed topography in alluvial channel bend. Journal of Hydraulic Engineering. Vol. 110(4) p. 521–532. DOI 10.1061/(ASCE)0733-9429(1984)110:4(521).
• PATRA K.C., KAR S.K., BHATTACHARYA A.K. 2004. Flow and velocity distribution in meandering compound channels. Journal of Hydraulic Engineering. Vol. 130(5) p. 398–411. DOI 10.1061/(ASCE)0733-9429(2004)130:5(398).
• ROZOVSKII I.L. 1957. Flow of water in bends of open channels. Kiev. Academy of Sciences of the Ukrainian SSR, Israel Program for Scientific Translations. ISBN 0706501586 pp. 233.
• SONG T., GRAF W.H. 1996. Velocity and turbulence distribution in unsteady open-channel flow. Journal of Hydraulic Engineering. Vol. 122(3) p. 141–154. DOI 10.1061/(ASCE)0733-9429(1996) 122:3(141).
• SONG T., CHIEW Y.M. 2001. Turbulent measurement in non-uniform open-channel flow using Acoustic Doppler Velocimeter (ADV). Journal of Engineering Mechanic. Vol. 127(3) p. 219–232. DOI 10.1061/(ASCE)0733-9399(2001)127:3(219).
• SUMIADI S., ISTIARTO, KIRONOTO B.A., LEGONO D. 2011. Developing laboratory experiment on flow in an erodible curved channel. Proceedings of the 4th ASEAN Civil Engineering Conference. 22–23.11.2011. Yogyakarta p. 223–226.
• TOMINAGA A., NAGAO M. 1998. Secondary flow structures in bends of narrow open channels with various cross section. Nagoya, Japan. Nagoya Institute of Technology.
• WAHL T.L. 2000. Analyzing ADV data using WinADV. Joint Conference on Water Resources Engineering and Water Resources Planning and Management. 30.07–2.08.2000. Minneapolis, Minnesota, United States p. 1–10. DOI 10.1061/40517(2000)300.
• YEN C-L., LEE K.T. 1995. Bed topography and sediment sorting in channel bend with unsteady flow. Journal of Hydraulic Engineering. Vol. 121(8) p. 168–179.

Uwagi

Opracowanie rekordu ze środków MEiN, umowa nr SONP/SP/546092/2022 w ramach programu "Społeczna odpowiedzialność nauki" - moduł: Popularyzacja nauki i promocja sportu (2022-2023).