Hydraulic characteristics of labyrinth sluice gate

Two hundred experiments were conducted on triangular cross-section gates, folded in one and two-cycle modes, with varying apex angles and opening heights under different upstream flow conditions. The results were analyzed and compared with standard gates under identical hydraulic conditions. The hydraulic performance of the proposed models was then evaluated. The models with smaller internal angles and one cycle demonstrated significant efficiency improvements. However, as the interior angle and/or cycle number increased, the efficiency improvements declined. The discharge coefficient values increased up to 200%, the percentage of upstream flow depth reduction reached more than 50%, the passing discharge achieved gains of up to 96%, and the rate of downstream Froude number reduction reached 70%. Finally, A reliable equation for the discharge coefficient was developed, yielding an RMSE of 5.459%, MAPE of 5.95%, and R2 of 0.9066. The results of this study can be beneficial in situations where high flow rates need to be accommodated, particularly in flood season, and minimize the risk of overflow, reducing the number of gates for a particular discharge; thereby, the supporting infrastructure's effective cost will minimize. Furthermore, it can help to mitigate erosion and maintain the stability of downstream environments. •The impact of geometric wall path shapes on the hydraulic characteristics of gates were investigated.•A triangular cross-section gates, which were folded in one and two-cycle modes, with varying apex angles were studied.•The discharge coefficient values increased up to 200%, the percentage of upstream flow depth reduction reached more than 50%.•A reliable equation for the discharge coefficient was developed.