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Urban stormwater is an important environmental problem, especially for metropolitans worldwide. The most important issue behind this problem is the need to find green infrastructure solutions, which provide water treatment and retention. Floating treatment wetlands, which are porous patches that continue down from the free-surface with a gap between the patch and bed, are innovative instruments for nutrient management in lakes, ponds, and slow-flowing waters. Suspended cylindrical vegetation patches in open channels affect the flow dramatically, which causes a deviation from the logarithmic law. This study considered the velocity measurements along the flow depth, at the axis of the patch, and at the near-wake region of the canopy, for different submerged ratios with different patch porosities. The results of this experimental study provide a comprehensive picture of the effects of different submergence ratios and different porosities on the flow field at the near-wake region of the suspended vegetation patch. The flow field was described with velocity and turbulence distributions along the axis of the patch, both upstream and downstream of the vegetation patch. Mainly, it was found that suspended porous canopy patches with a certain range of densities (SVF20 and SVF36 corresponded to a high density of patches in this study) have considerable impacts on the flow structure, and to a lesser extent, individual patch elements also have a crucial role.
Ayşe Yüksel Ozan; Didem Yılmazer. Near-Wake Flow Structure of a Suspended Cylindrical Canopy Patch. Water 2019, 12, 84 .
AMA StyleAyşe Yüksel Ozan, Didem Yılmazer. Near-Wake Flow Structure of a Suspended Cylindrical Canopy Patch. Water. 2019; 12 (1):84.
Chicago/Turabian StyleAyşe Yüksel Ozan; Didem Yılmazer. 2019. "Near-Wake Flow Structure of a Suspended Cylindrical Canopy Patch." Water 12, no. 1: 84.
This study focuses on the effects of one-line emergent natural tree (Cupressus Macrocarpa) planted at the edge of the floodplain in a compound open-channel flow. The flow velocity and water level are measured and used to analyze the flow structure. The time averaged and depth-averaged streamwise velocity distributions with root mean square (rms) and time series of streamwise velocity distrbution are analyzed. The velocity distribution considerably changes along the compound channel. The streamwise velocity distribution fits with logarithmic distribution in the non-vegetated case, but for vegetated cases, the streamwise velocity distribution shows S shaped profile at the 1/3 part of floodplain (Bf / 3) and main channel (Bm / 3) close to the boundary between floodplain and main channel. Additionally, it is obtained that the presence of tree line increases turbulence intensity over the compound open-channel. Moreover, an oscillation period is obtained in the flow caused by tree line by analyzing time series of the streamwise velocity distribution. The oscillation is present everywhere in the floodplain and present at almost Bm / 3 part of the main channel which is close to the junction between floodplain and main channel.
Ayse Yuksel Ozan. Flow structure at the downstream of a one-line riparian emergent tree along the floodplain edge in a compound open-channel flow. Journal of Hydrodynamics 2018, 30, 470 -480.
AMA StyleAyse Yuksel Ozan. Flow structure at the downstream of a one-line riparian emergent tree along the floodplain edge in a compound open-channel flow. Journal of Hydrodynamics. 2018; 30 (3):470-480.
Chicago/Turabian StyleAyse Yuksel Ozan. 2018. "Flow structure at the downstream of a one-line riparian emergent tree along the floodplain edge in a compound open-channel flow." Journal of Hydrodynamics 30, no. 3: 470-480.
Aquatic vegetation in rivers and coastal regions controls the flow structure in terms of mean velocity and turbulence. The vegetation in the flow affects the transportation of nutrients, microbes, dissolved oxygen, sediment, and contaminants; therefore, the flow characteristics of different types of vegetation layers should be examined in order to understand the effects of vegetation on the flow structure. In this paper, the effect of the submergence ratio and SVF (Solid Volume of Fraction) of a vegetation patch, which was present across half of the channel in a spanwise direction, on the flow structure at the wake region was examined. For this purpose, different submergence ratios with different SVFs were considered in the experiments, and velocity measurements were performed in the wake region of the vegetation layer with an Acoustic Doppler Velocimeter (ADV). According to the results, the effect of different vegetation heights and SVFs on the velocity distribution was obtained. Moreover, inflectional velocity distribution over the cross-section in the wake region of the vegetation layer was obtained, and it was concluded that jet flow occurred in the non-vegetated half of the channel due to the vegetation layer.
Didem Yılmazer; Ayse Yuksel Ozan; Kubilay Cihan. Flow Characteristics in the Wake Region of a Finite-Length Vegetation Patch in a Partly Vegetated Channel. Water 2018, 10, 459 .
AMA StyleDidem Yılmazer, Ayse Yuksel Ozan, Kubilay Cihan. Flow Characteristics in the Wake Region of a Finite-Length Vegetation Patch in a Partly Vegetated Channel. Water. 2018; 10 (4):459.
Chicago/Turabian StyleDidem Yılmazer; Ayse Yuksel Ozan; Kubilay Cihan. 2018. "Flow Characteristics in the Wake Region of a Finite-Length Vegetation Patch in a Partly Vegetated Channel." Water 10, no. 4: 459.