The ‘Bajo Grande’ Wastewater Treatment Plant has a design capacity of 2.78 m³/s, and discharges into the Suquia River (Córdoba, Argentina). The river has an average flow rate of 10 m³/s, with lower values during the summer. Currently, the treatment plant does not have an accurate discharge-measurement system prior to the discharge into the river, which makes it difficult to evaluate the dosing of the disinfection treatment. The outflow rate is measured in a straight flume. However, at the inlet section of the flume, a 180° sharp bend induces a complex turbulent flow with instabilities and low-frequency velocity fluctuations which are not appropriate for flow quantification. In this type of flow, most of the in situ flow discharge-measurement systems have great uncertainty. Therefore, in situ flow measurements with an Acoustic Doppler Current Profiler, Large-Scale Particle-Tracking Velocimetry techniques and a prototype-scale Detached Eddy Simulation model were combined to obtain a detailed characterization of the turbulent flow. The results provide flow rates, fields of mean flow velocity, temporal evolution, and characteristic parameters of the turbulence. This allowed a better understanding of the effects of turbulence and flow instabilities. The results provide a basis to validate numerical models used in the hydraulics design of contact chambers to improve the disinfection process.

'Bajo Grande' 污水处理厂的设计容量为 2.78 m ³ /s，排入 Suquia 河（阿根廷科尔多瓦）。这条河的平均流速为 10 m ³ /s，夏季时值较低。目前，处理厂在排入河流之前没有准确的排放测量系统，这使得难以评估消毒处理的剂量。流出速率在直槽中测量。然而，在水槽的入口部分，一个 180° 的急弯会导致复杂的湍流，具有不稳定性和低频速度波动，不适合流量量化。在这种类型的流动中，大部分原位流量测量系统具有很大的不确定性。因此，结合使用声学多普勒电流剖面仪、大规模粒子跟踪测速技术和原型尺度分离涡流模拟模型的原位流动测量，以获得湍流的详细表征。结果提供流速、平均流速场、时间演变和湍流特征参数。这有助于更好地理解湍流和流动不稳定性的影响。结果为验证用于改进消毒过程的接触室水力学设计中的数值模型提供了基础。