Hydraulic Performance Optimization of Triangular-Arced Asymmetric Labyrinth Weirs: Experimental Analysis of Discharge Efficiency and Geometric Variations

This study examines the hydraulic performance of triangular-arced asymmetric labyrinth weirs with varying middle cycles, focusing on optimizing the discharge coefficient (Cd) under different geometric and hydraulic conditions. Experimental investigations were conducted in a flume with triangular-arced weirs featuring arc angles of 45°, 90°, and 135°. The results indicate that the highest Cd of 0.949 was achieved at a Froude number (Fr) of 1.64 and an arc angle of 90°, demonstrating optimal hydraulic performance. Wider intermediate cycles (R/W1=3.2) enhanced Cd to 0.949, while narrower cycles (R/W1=2.5) yielded a lower Cd of 0.633 due to increased turbulence and flow interference. The Q-Ht curves revealed that reducing the apex width (W1) increased upstream hydraulic head, enhancing discharge coefficient at low discharges but reducing hydraulic efficiency at higher discharges due to turbulence. These findings confirm that modifying intermediate cycles and optimizing arc angles can significantly improve hydraulic efficiency.