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... Inlet boundary conditions are referred to as concurrent if outlet velocity and position are specified. In such cases, the outlet boundary conditions must also include the distribution of total flow variables, especially flow velocity [10]. This variable is critical in analyzing total flow and is often discussed in the context of these boundary conditions. ...
In the field of river engineering, complex flow behavior emerges at acute bends in waterways such as rivers or streams. Thus, understanding the flow structure, especially along the banks, is critical. Due to the river's turbulence , obtaining all necessary details through field observation and lab experiments is challenging, time-consuming, and expensive. Computational fluid dynamics (CFD) is a common approach used to predict flow behavior and analyze water retention structures. The site of the meandering bend of the Beas River is located in Mandi town, in the Mandi district of H.P. The geometry of the site is curvilinear, and a retaining wall is to be constructed there. The retaining wall along the left side of the river is 490 m long, while the right-side wall is 495 m. The river's inlet width is 90 m, and the outlet width is 95 m. The channel depth is 5 m, and the channel geometry bed slope is constant throughout the river's length [1]. The Reynolds-averaged Navier-Stokes (RANS) equations are solved using the standard k-ω turbulent model, and numerical simulations are performed using ANSYS FLUID FLUENT. The results indicate that as the length of the retaining wall increases, the wall shear stress increases up to a certain length, then decreases towards the outlet. Additionally, the inner bank, or convex side, of the meandering curve always has a higher longitudinal velocity, while the inner side, or concave side, has a lower longitudinal velocity [2].
... One of the ways to reduce or eliminate the variation of flow velocity in the transvers direction is by increasing the bed roughness close to one side than the other. This prospective study was designed to investigate the use of artificial bed roughness such as cubic and T-section shapes located in one side above the channel bed in the longitudinal direction to increase the manning coefficient in this region and hence reduce the erosion of the bed [3]. Recently, several studies that investigated an artificial bed roughness have been carried out on increasing the manning coefficient in the open channel flow. ...
... Recently, several studies that investigated an artificial bed roughness have been carried out on increasing the manning coefficient in the open channel flow. Most studies in this field have investigated the effect of these roughs on the whole bed surface such as Noori and Saeed [4], Graf and Blanckaert [5], Hendratta et al. [6], Ibrahim and Noori [7], Pradhan et al. [8], Khoudja and Soudani [9], Yousfi and Aliane [10], and Majeed and Ghazal [3], who conducted a series of CFD simulations with the k-ω SST model were used to calculate Manning's coefficient of artificial geometric roughness element. These elements were placed on the flume's bed and were subjected to various transverse spaces and different angles of attack. ...
Experimental and numerical studies have been conducted on the effects of bed roughness elements such as cubic and T-section elements that are regularly half-channel arrayed on one side of the river on turbulent flow characteristics and bed erosion downstream of the roughness elements. The experimental study has been done for two types of bed roughness elements (cubic and T-section shape) to study the effect of these elements on the velocity profile downstream the elements with respect to different water flow discharges and water depths. A comparison between the cubic and T-section artificial bed roughness showed that the velocity profile downstream the T-section increased in smooth side from the river and decrease in the rough side from it compared with the case when a cubic artificial bed roughness is used. By comparing the results for the element shapes, it can be notices that the T-section bed roughness element more effective compared to cubic shape for both sides of the channel. The numerical method has been done using Computational Fluid Dynamic (CFD) method. A validation for the CFD model with the experimental study have been carried out for a specific flow discharge and water depth. The results indicated that the velocity distribution profiles downstream the bed roughness elements in both sides shown very good agreement for manning coefficients between the numerical and experimental studies. The range of errors between the experimental and numerical study have been calculated using Root Mean Square Error (RMSE) approach, which is found that the RMSE is approximately equal to 1 in case of cubic bed roughness and the RMSE is about 1.5 in case of T-section bed roughness for both smooth and rough sides. Furthermore, the influence of the velocity profile and the bed erosion downstream of the T-section element under the effect of tides have been investigated using the CFD method, which is commonly happened in Shat al-Arab south of Iraq. The results show that the tide of the flow has a reverse effect on the velocity profiles for both sides. Since the velocity profile downstream of bed roughness region increase in the rough side and decrease in the smooth side compared with the normal flow of the river.
Introduction. The authors present one of methods for measuring water flows through the intake of a hydroelectric power plant. The new structure has a metal frame and a folding rotary row. The authors analyzed the advantages of the proposed, and mase strength and hydraulic analyses. Computational studies of the stress-strain state, made with account taken of the actual hydrodynamic pressure, allow choosing the optimal position of measurement points, designing a frame structure, and making highly accurate measurements of energy characteristics.
Materials and methods. Top international publications, as well as archived materials, were analyzed to select the universal frame structure. The most promising directions were identified; the advantages and disadvantages of the proposed solutions were taken into account. Complex computational studies were performed using ANSYS Mechanical, a universal industrial software package, and ANSYS CFX, a specialized module for modeling flows of liquids and gases with account taken of turbulence.
Results. The position of measurement points that ensure the least distortion of the flow and tilt angles of hydraulic turntables were determined during the hydraulic simulation. The flow loads were taken into account when the stress-strain state of the universal frame structure was calculated; optimal design solutions were selected to ensure the strength and reliability of metal elements. Stress concentration zones were identified for monitoring purposes during installation.
Conclusions. Given the mathematical modeling data and experimental field studies, a universal frame structure for energy tests was substantiated. The new design ensures a measurement error of ±0.67 %, which corresponds to the leading world standards.
