Microwave Sensing of Turbulent Flow Processes for Intelligent Drainage Monitoring and Management

BACKGROUND / RATIONALE :

The project aims to develop new instrumentation and new scientific understanding that together will enable the non-intrusive assessment of flow processes in large drainage networks.

The need to accurately monitor flows within large drainage systems is an emerging challenge, driven by the effects of urbanisation, climate change and population change that alter the hydraulic load on drainage assets. Accurate and widespread monitoring of flow, turbulence and sedimentation is critical for the timely prediction and mitigation of flood events. Existing non-intrusive methods only estimate surface velocity and/or flow depth and are limited to specific flow conditions, with varied measurement error. Measurements of turbulence and the spatial characteristics of free surface flows (which govern mixing and transport of sediments /pollutants) are too expensive, energy-intensive, or invasive for widespread deployment.

There is hence a demand from industry for non-intrusive characterisation of turbulent flow processes. Research has linked these processes to the dynamic free-surface pattern but so far our ability to measure this pattern is limited and it has only been examined in detail for flows in rectangular channels. The sensing technology developed by Dynamic Flow Technologies Ltd (DFT) has the potential to provide detailed free-surface data, and the unique pipe rigs at Sheffield enable the necessary hydraulic examinations.

The aim of this project is to study the fundamental mechanics of flowing water surfaces in partially-filled circular pipes, their relationship with underlying flow processes, and their influence on incident electromagnetic fields. This will result in novel low-cost sensing technology; a step change enabling the widespread and non-intrusive monitoring and management of drainage infrastructure.

RESEARCH CHALLENGE / QUESTIONS :

i. The performance of DFT’s microwave transducers must be characterised, and a transducer array developed to enable three-dimensional measurements of the dynamic flow surface in (ii).

ii. To reconstruct the 3D surface pattern from the measured data, an inverse method adaptation must be developed by solving the vector problem involving the two potentials of the electromagnetic field.

iii. A model or database must enable inference of the underlying flow/turbulence conditions in partially-filled pipes from the measured free-surface data. Hence, using the parameters of the new model from step (ii), the free-surface characteristics must be linked directly to the measured flow field beneath.

iv. The resulting sensor must be validated in the laboratory and in the field.

Anticipated Outcomes & Benefits for the Sponsoring Organisations and Other Stakeholders :

The potential outputs of this project will have transformative potential for end users such as Network rail, water companies and the Environment Agency, who will achieve cost savings via more effective asset management, compliance strategies, and investment of resources. It will also benefit the public through the reduction of harmful flood events and reduced disruption of Network Rail’s services.

The Potential Scientific Contribution of the Project, together with any other Innovative Aspects :

The new free-surface understanding will be transformative in enabling deeper study of processes that interact with turbulent flow surfaces, such as greenhouse gas evasion, EM wave scattering, and pollutant mixing. The approach of using the free-surface to infer the underlying processes is novel and innovative, the relationships derived for partially-filled pipes will be new, and it will represent a significant contribution to field of hydraulics.