Author(s): Bambang Agus Kironoto, Bambang Yulistiyanto, Budi Wignyosukarto, Bambang Triatmodjo, Erwin Nur Afiato, Rahmat Bangun Giarto
Linked Author(s): Bambang Kironoto
Keywords: Non-uniform open-channel-flow, velocity, suspended-sediment, field measurement
Abstract: The characteristics of suspended sediment flow in open channel flows are often required in hydraulic engineering design, such as, in irrigation-canals design, design of reservoirs, river improvement, etc. The suspended sediment data, however, is often unavailable, or if there is, the availability of such data is very limited due to the complex and costly procedure in obtaining the data during the field measurements. The existence of non-uniformity of the channel is expected to affect the characteristics of suspended sediment flow, especially when compared to those known in uniform open channel flow and thus need to be studied in more detail. The suspended sediment characteristics in non-uniform open channel flow, such as velocity distribution, friction velocity, and suspended sediment concentration distribution, are studied based on 144 of velocity and suspended sediment concentration profiles. They are measured in narrowed and widened channels, at three different locations on Mataram Irrigation Channel, in Yogyakarta, Indonesia. The suspended sediment concentration profiles were measured by using Opcon Probe, while the velocity profiles were measured by using propeller current meter probe. The findings of the research showed that closer to the edge of the channel, the velocity profile become fuller and smaller, as well as the suspended sediment concentration profile become smaller closer to the side walls. The equations of Rouse and of Tanaka-Sugimoto give good predictions for the concentration of suspended sediment measured in the center of the channel, while near to the edge of the channel, the equations require a correction factor, namely, ?-value. The existence of suspended sediment concentration and the changes of flow velocity due to narrowed and widened channels influence the friction velocity values. The results of the friction velocity, u*, by Clauser's method for the data evaluated in this study show a specific pattern in narrowed and widened channels
Year: 2017