Experimental study on characteristics of discharge coefficient of hydraulic flap gate

Abstract

翻板闸门开启后,门上门下两层泄流,为堰、孔混合流,复杂的流态给工程的水力设计带来了难度,现有研究均是以求得综合流量系数为目标。为分开讨论在堰、孔独立出流时的相互影响,通过开展模型试验,基于翻板闸最大开度工况下的过流特性,研究来流量大小和下游水深对翻板闸过流能力的影响。试验来流量分别为0.06、0.08、0.10、0.12 m~3/s,下游水深分别为0.50、0.55、0.60、0.65 m的工况组合,共16种工况进行试验。试验结果表明下游水深一定时,流量系数与来流量呈正相关关系;来流量一定时,流量系数与下游水深呈负相关关系。该研究成果基于大开度工况,可进一步研究其他工况的流量系数。 The discharge consists of both weir flow and orifice flow after opening a flap gate, which brings difficulty to hydraulic engineering design.The previous research was mainly aimed at determining the comprehensive discharge coefficient.To discuss the mutual influence of the weir flow and the orifice flow when they function separately, the physical model experiments were conducted to investigate the influence of the flow and the level of the tail water onto the flow passage ability through the flap gate, under the condition of the maximum opening of the gate.The tests involved the combinations of the flow rates of 0.06, 0.08, 0.10, and 0.12 m3/s and the levels of the tail water of 0.50, 0.55, 0.60 and 0.65 m, a total of sixteen testing conditions.The results showed that when the level of tail water was constant, the discharge coefficient and flow rate were positively correlatedMergeCellwhen the flow rate was constant, the discharge coefficient and the level of downstream water were negatively correlated.While these findings were based on the maximum opening of the flap gate in this study, more experiments will be carried out to study the discharge coefficients under other conditions.