Showing 3 results for Separation Zone
A. Keshavarzi, M. J. Kazemzadeh Parsi,
Volume 10, Issue 1 (4-2006)
Abstract
Flow structure at water intake is very complicated and three-dimensional. Due to this the application of one and two-dimensional equations can not sufficiently explain the flow structure at water intake. In this study, the simulation of flow structure at a 45 degree water intake was investigated numerically and experimentally. Here, the characteristic of separation zone and velocity distribution at 45 degree water intake were investigated using Standard k-ε and RNG k-ε models. It was found that the Standard k-ε model enables to estimate the flow and separation zone at water intake. Also, the location of separate zone at the inlet of water intake was studied using experimental and numerical approach. It was found that the separation zone at 45 degree water intake occurs at the downstream of the inlet.
E Izadi, M Heidar Pour, A Kabiri Samani,
Volume 12, Issue 46 (1-2009)
Abstract
In this study, the flow characteristics have been investigated by measuring separation zone, surface and velocity profiles over the circular crested side weirs. An equation was proposed for the length of the separation zone using dimensional, statistical and regression analysis. The dimensional analysis showed that the length of separation zone depends on the upstream to the downstream water depth over the side weir, channel width to the downstream water depth and the Froude number. Comparison of the longitudinal and sectional surface profiles showed that the surface profiles at the vicinity of the side weir are non-uniform, due to separation zone close to the side weir. Therefore, the suitable place for measuring the characteristics of flow is along the centre line of the channel. It was observed that the maximum velocity occurred below the surface water which might be due to the secondary flow around the side weir. By increasing the distance far enough from the side weir, the effects of secondary flow were minimized and the velocity profiles tended to be uniform.
M. R. Taghizadeh, A. Motamedi, M. Galoie, F. Kilanehei,
Volume 27, Issue 4 (12-2023)
Abstract
Understanding flow behavior over bedforms is one of the most complex topics in sedimentary engineering. Despite numerous studies that have been conducted on river beds, the understanding of the interaction between flow and bed in turbid and clear waters is still impoverished. The present study mainly focused on simulating clear and turbid flows using SSIIM software. This study modeled the flow through a 12-meter channel with nine consecutive dunes of 1-meter length and 4 cm height. Nine simulations were performed to investigate the effects of flow velocity and flow separation zone in clear and turbid water. Finally, the results were compared with the experimental results of previous researchers using the PIV. The modeling results showed that the length of the flow separation zone increases with increasing velocity, and the highest probability of flow separation occurs at the highest velocity. In turbid flow, flow separation is less than the same flow condition in clear flow, and as fluid density increases, the length of the flow separation zone decreases. This study demonstrates the acceptable functionality of the SSIIM software and its accuracy in estimating flow behavior with and without sediment.
