Optimizing energy dissipation in trapezoidal channels is crucial for effective flow management and ensuring the stability of hydraulic structures. This experimental study investigates the influence of isosceles triangular obstacles arranged in a zigzag pattern on energy dissipation within a 6-meter-long trapezoidal flume, characterized by a top width of 60 cm, a base width of 16 cm, and a wall angle of 75°, conducted at the Hydraulic Laboratory of the Civil Engineering Department, Azerbaijan Shahid Madani University. The experiments involved obstacles with heights of 2, 3, and 4 cm, arranged in nine distinct zigzag configurations, and tested under flow rates ranging from 2.3 to 84.6 liters per second. Data collection utilized advanced instrumentation, including an ultrasonic flow meter, a depth gauge, and a micro-propeller velocity meter with an accuracy of 0.01 m/s. The collected data were meticulously analyzed using Excel and SPSS (version 26), with statistical significance verified through ANOVA (p < 0.05) to ensure the reliability of the findings.

The results revealed that the zigzag arrangement significantly enhanced energy dissipation by 22.4%, reducing specific energy from 0.15 m to 0.12 m. This configuration also led to a 20% reduction in downstream depth and a 20% improvement in the uniformity of energy distribution across the channel. Furthermore, turbulence intensity was reduced by 15%, contributing to a more stable flow regime, while hydraulic resistance increased by 12%, with the drag coefficient (Cd) rising to 1.45 compared to 1.0 for a smooth bed. The optimal obstacle spacing, defined by the ratio S/B = 0.3, improved flow stability by 18%, ensuring consistent hydraulic performance. In comparison to alternative designs, such as wavy beds that achieved 15% energy dissipation, the zigzag configuration demonstrated a 7% superior performance, highlighting its effectiveness in energy management.

Dimensional analysis, incorporating parameters such as h/y₁ = 2 and Fr₁ = 3.33, along with empirical modeling yielding a high correlation coefficient (R² = 0.93), validated the precision and consistency of the experimental results. These findings underscore the robustness of the proposed design in optimizing hydraulic performance. From a practical perspective, the zigzag arrangement offers significant economic and operational benefits. It reduced the construction costs of stilling basins by 40%, making it a cost-effective solution for hydraulic infrastructure. Additionally, it enhanced hydraulic efficiency by 25%, improving the overall performance of the system under high-energy flow conditions.

The study also explored the influence of obstacle height and flow rate variations on energy dissipation and flow characteristics. Higher obstacles (4 cm) were found to maximize energy dissipation under higher flow rates, while lower obstacles (2 cm) were more effective in maintaining flow stability at lower discharges. The zigzag pattern’s ability to disrupt flow and induce controlled turbulence proved instrumental in achieving these outcomes. The statistical analysis further confirmed that the observed improvements were significant and not due to random variations, reinforcing the reliability of the results.

This research provides a scientifically robust and practical solution for managing high-energy flows in hydraulic structures. By integrating cost-effective design modifications with enhanced hydraulic performance, the proposed zigzag arrangement of triangular obstacles offers a viable approach for engineers and designers working on trapezoidal channels. The findings have implications for the design of stilling basins, spillways, and other hydraulic structures where energy dissipation and flow stability are critical. This study contributes to the body of knowledge in hydraulic engineering and offers a scalable solution for real-world applications, balancing efficiency, stability, and economic feasibility in the management of high-energy flows.