3D Investigation of Flow Hydraulic in U Shape Meander Bendswith Constant, Decreasing and Increasing Width
Journal Title: Journal of River Engineering - Year 2014, Vol 2, Issue 3
Abstract
In meandering rivers, the flow pattern is highly complex, with specific characteristics at bends that are not observed along straight paths. A numerical model can be effectively used to predict such flow fields. Since river bends are not uniform– some are divergent and others convergent–in this study, after the SSIIM 3-D model was calibrated using the result of measurements along a uniform 180° bend with a width of 0.6 m, two similar but convergent 180° bend, 0.6 m to 0.45 m wide and divergent 180° bend, 0.6 m to 0.75 m wide, was simulated using the SSIIM 3-D numerical model. Flow characteristics of the 180° bends, including lengthwise and vertical velocity profiles, primary and secondary flows, lengthwise and widthwise slopes of the water surface and the helical flow strength, were compared with each other. The verification results of the model show that the numerical model can effectively simulate the flow field in the uniform bend. In addition, this research indicates that, in a convergent channel, the maximum velocity path at a plane near the water surface crosses the channel’s centerline at about a 30° to 40° crosssection, while this occurs at about 50° cross section within divergent channel and about 55º for uniform one. The varying range of the water surface elevation is wider in the convergent channel than in the other ones, and the strength of the helical flow is generally greater in the divergent channel than in the uniform and convergent one, respectively. Also, unlike the uniform and divergent bends, the convergent bend exhibits no rotational cell against the main direction of secondary flow rotation at the 135° cross-section.
Authors and Affiliations
Ali Liyaghat - Kamran Mohammadi - Mostafa Rahmanshahi
Keywords
Related Articles
- EP ID EP32966
- DOI -
- Views 376
- Downloads 0
Effect of Submerged Vanes on Intake Ratio and Water Surface profile at 55° Diversion
Submerged vanes are commonly used as hydraulic structures for sediment control at intake entrance. In the present research which was undertaken at the Hydraulic Laboratory in Water Engineering Department of Shiraz Univer...
Floodplain Modeling Using HEC-RAS and MIKE11 Models
A significant deficiency of most computer models used for stream floodplain analysis is that the locations of structures impacted by floodwaters, such as bridges, roads, and buildings, cannot be effectively compared t...
Evalution of Landsat ETM Sensor To Separate Riparian Forest from River (Case Study: Maroon River – Khuzestan)
In order to evaluate Landsat satellite imagery and remote sensing applications in separation of land from the river in riparian forest of Maroon Behbahan, a small window of multispectral images Landsat ETM+ was chosen...
Estimation of Flood Warning Times for Flood Safety Management Downstream of Dams
Floods have always been a threat for people and property due to the extent of possible damages. The flooding could be catastrophic in case of possible dam failure and its impacts on downstream areas could also be very...
Delineation of Possible Extent of Flooding in Creeks by HEC-GEORAS
This research emphasizes the estimation of overbank flooding in creeks and delineation of the extent of flooding in GIS format. For the purpose, a very versatile tool HECGeoRAS has been utilized with the combination of...