The application of a piano key (PK) weir in a channel may lead to changes in the flow characteristics, upstream siltation conditions, and bed elevation. In this study, laboratory-based Type-A PK weir models with noses below the upstream apexes were studied under different flow and siltation conditions. A total of 342 datasets were collected from the three models. Upstream siltation had no impact on the discharge efficiency of submerged PK weirs, but under the free-flow condition, there was a maximum reduction of 4% in the coefficient of discharge. Planners and designers must consider such variations in channels with a high sediment load. However, at high H/P (where H is the head over the weir crest and P is the weir height), the siltation effect starts to decrease, possibly due to the alternation in the flow condition caused by tailwater submergence. The modular submergence was found to be approximately 0.5, which is close to the values available in the literature. The proposed equations for free-flowing PK weirs performed very well with a maximum error of approximately 7% and a mean absolute percentage error (MAPE) of approximately 2.5%. Furthermore, approximately 60% of the data lie within the ± 3% error bands, and almost all data lie within the ± 6% error bands. The equations proposed for submerged PK weirs also efficiently estimated the coefficient of discharge with a maximum error ranging from 9.0 to 11.32% and an MAPE varying from 2.94 to 4.27%.

在通道中使用钢琴键（PK）堰可能会导致流动特性，上游淤积条件和床高的变化。在这项研究中，研究了在不同的流量和淤积条件下，鼻子低于上游顶点的基于实验室的A型PK堰模型。从这三个模型中总共收集了342个数据集。上游淤积对淹没式PK堰的排放效率没有影响，但在自由流动条件下，排放系数最大降低了4％。计划者和设计者必须考虑高泥沙量的河道中的这种变化。但是，在高H / P（其中H是堰顶上方的头，P是是堰高），淤积效应开始减弱，这可能是由于尾水淹没引起的流动状态变化所致。发现模块浸没约为0.5，接近文献中可用的值。提出的自由流动PK堰方程非常好，最大误差约为7％，平均绝对百分比误差（MAPE）约为2.5％。此外，大约60％的数据位于±3％的误差带内，几乎所有数据都位于±6％的误差带内。为淹没式PK堰提出的方程式还可以有效地估算出排放系数，最大误差范围为9.0至11.32％，MAPE为2.94至4.27％。