Characteristics of flow over rectangular labyrinth weirs with round corners

Abstract

The hydraulic performance of round-cornered rectangular labyrinth weirs with varying weir heights and effective lengths has not been explored in the existing literature to the authors’ knowledge. The purpose of this experimental study was to see how the height and effective length of round-cornered rectangular labyrinth weirs affect their discharge efficiency. Nine flat-crested rectangular labyrinth weirs made of high-density polyethylene (HDPE) were tested in a rectangular flume under various discharges to fulfill the goals of this study. The discharge coefficients for the weirs were then calculated. The hydraulic efficiency of weirs with round corners increases as the weir height (P) increases, according to the findings; however, with effective length of the weir to channel width ratios (LC /B) ≤ 1.78, the effect of the weir height diminishes. For the HT /P ranges used in this study, 0.1 ≤ HT /P ≤ 0.65, the round-cornered rectangular labyrinth weirs with higher LC /B ratios (greater M values) showed improved hydraulic efficiency. Furthermore, the effects of the round-cornered rectangular labyrinth weirs’ headwater inflation can be mitigated by increasing the effective length of the weirs;by increasing M values (LC /B ratios). Using multiple linear regression analysis, a satisfactory correlation equation was found between discharge coefficients of round-cornered rectangular labyrinth weirs, CB, and the other parameters, LC, P, and h.