Introduction
In this research, a comprehensive laboratory investigation of the combined weir with a bottom gate was conducted to examine its performance under varying hydraulic conditions. This type of structure is significant in hydraulics and water management as it combines the benefits of both a weir and a gate, by providing controlled flow regulation while minimizing hydraulic losses.
Methodology
The experiments related to this research were carried out in the hydraulic laboratory of the Faculty of Agriculture at the University of Birjand. The study was performed in a rectangular channel measuring 10 meters in length, 0.5 meters in height, and 0.3 meters in width. To assess and calculate the flow coefficient, the experiments were conducted under two distinct configurations: (1) at constant Gate openings with varying flow rates, and (2) at constant flow rates with different Gate openings. These experiments were executed at two slopes of 0.002 and 0.004, allowing for a detailed analysis of how slope influences flow characteristics.
Results and Discussion
The results of the present study indicated that as the dimensionless parameter Y/D (the height of water on the Gate compared to the height of the channel) increased, the discharge coefficient exhibited a downward trend. Conversely, a decrease in Y/D led to an increase in the discharge coefficient, approaching a value of 0.76. Furthermore, the increase in the dimensionless parameter H_g/D corresponded to a rise in the flow coefficient, which remained within the range of C_T≤0.72. Notably, variations in the slope of the channel floor did not produce significant changes in the discharge coefficient of the structure, suggesting that other factors may play a more critical role in achieving optimal hydraulic performance.
Conclusion
Comparing the findings of the present research with existing studies by other scholars in this area reveals a commendable consistency in results. This alignment underscores the validity of the current research methodology and findings, indicating that the combined weir with a bottom gate operates efficiently under the tested conditions. The insights gained from this study contribute to the ongoing discourse on hydraulic structure optimization in water resource management.