Velocity field measurement with UB-flow profiler allows a better understanding of sewer networks.
During heavy rains, part of the wastewater can be discharged into the environment (sea, river) without any treatment. At the same time, various studies (e.g. Mallin and al. 2006) show that urban effluents contribute significantly to the deterioration of the quality of aquatic environments that have a direct impact on biodiversity and water activities.
The knowledge of the behavior of sewer networks and facilities allows a better sizing of those and therefore contributes to a reduction on their overall impact on the environment. In a similar way, the active management of the network (real-time control to avoid discharges), based on a reliable and accurate metrology, can significantly reduce pollution. In any cases, a better understanding of the hydraulic behavior allows a suitable management of these networks.
The UB-flow ultrasonic profiler, developed and produced by UBERTONE, continuously measures the velocity profile along an axis (acoustic beam). When the device is positioned appropriately, the information contained in the velocity profile may allow the user to calculate the flow rate with high accuracy. The photo shows an example against mounting system suitable for measuring flow in a rectangular channel. In case of sedimentation, the UB-flow profiler can be installed on the side wall, above the layer of sediment at an oblique shooting angle.
The use of the UB-flow field profiler allows the measurement of the velocity distribution along a line in a sewer section. The chart below shows the velocity profile measured on a wastewater collector using UB-flow profiler placed on the surface and shooting down. These results were obtained in collaboration with the Hydrology and Sewerage group from the IFSTTAR (ex-LCPC).
The UB-Flow velocity profiler allows the improvement of the hydraulic knowledge of sewer systems by viewing, for example, the effect of upstream flow disturbances (branch, bend, etc..) or transitory regime. In particular, it allows the observation of a velocity profile during rain events, usually unreachable by measurement because of security constraints.