Piano key weirs (PKWs) are an improved form of labyrinth weirs, which are becoming popular as a more hydraulically efficient and cost-effective type of weir over its counterparts for both spillway and river flow conditions. More than thirty PKWs are already in construction worldwide, with constructions in India at Swara Kuddu. More than twenty parameters influence the flow over a PKW, and as such, the flow hydraulics near PKW is complex. It is imperative to study the performance of different shapes of PKW to know which shape offers more hydraulically and cost-effective advantages over other shapes. The present study combines the experimental and numerical study of discharge capacity and sediment carrying capacity of the different plan geometries of PKW. The experimental study of the discharging capacity of PKW has been carried out at eighteen discharge points for three plan geometries of PKW. A numerical study using ANSYS FLUENT has also been carried out at five discharges and compared with the experimental results. Vertical velocity near a weir is an essential factor facilitating the uplift of sediment. Sediment profile in the channel has been studied at three discharges experimentally for two types of PKWs: RPKW and TPKW6, all for free-flow conditions. The numerical study has also been carried out at these experimental discharges for studying the vertical component of velocity (v) upstream of PKW. An attempt has been made to isolate critical areas where the sediments are being lifted by the turbulence mechanism, thus helping them pass over the weir. The study shows PKW with a rectangular plan (RPKW) to be more hydraulically efficient than TPKWs with six-degree and thirteen-degree lateral crest variations (TPKW6 & TPKW13). The study also shows RPKW to be more self-cleaning in nature than its trapezoidal counterpart (TPKW6). Numerical study shows a close resemblance to the experimental results with errors well within permissible limits implying its greater use in ascertaining complex flows around hydraulic structures.

钢琴键堰（PKW）是迷宫型堰的一种改进形式，在溢洪道和河流流量条件下，它作为一种水力效率更高，成本效益更高的堰变得越来越受欢迎。全球已有30多个PKW在建，印度的Swara Kuddu也在建设中。超过20个参数会影响PKW上的流动，因此，PKW附近的流动液压系统很复杂。必须研究不同形状的PKW的性能，以了解哪种形状比其他形状在液压和成本效益方面更具优势。本研究结合了PKW不同平面几何形状的排沙量和泥沙承载量的实验和数值研究。在三种平面几何形状的PKW的18个放电点上进行了PKW放电容量的实验研究。还使用ANSYS FLUENT在5次放电时进行了数值研究，并与实验结果进行了比较。堰附近的垂直速度是促进沉积物上升的重要因素。对于两种类型的PKW：RPKW和TPKW6，均在自由流动条件下，通过三个排放实验研究了河道中的泥沙分布。还对这些实验放电进行了数值研究，以研究PKW上游速度（v）的垂直分量。已经尝试隔离湍流机制将沉积物抬起的关键区域，从而帮助它们越过堰。研究表明，带有矩形平面的PKW（RPKW）比具有六度和十三度横向波峰变化（TPKW6＆TPKW13）的TPKW具有更高的液压效率。研究还表明，RPKW在本质上比其梯形副本（TPKW6）更自清洁。数值研究表明，该实验结果与实验结果极为相似，其误差在允许的范围内，这表明该方法在确定水力结构周围的复杂流动方面具有更大的用途。