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Nandini Chidambaram (N.) MSc.


Room: HR N146
Tel.: +31(0) 53 489 6713
Position: PhD-student

Main Research Interest / Name of Research Project

Non-collinear wave mixing with phased array transducers: Drinking water mains are degrading over time and the current state of a particular piece of pipe material is mostly unknown. Often, assets which are still in good condition are replaced prematurely, resulting in increased cost and material use, whereas, other assets fail before the expectation time. Inspection of the drinking water supply mains is of great benefit to determine the state of the assets because, it gives insight of its current condition, which can be used for its effective replacement or maintenance. With smart replacement strategies, the use of raw materials and replacement cost can be reduced, enhancing better water supply with high quality drinking water and a very low downtime.

Non-destructive ultrasonic testing is a common inspection means, however, there is much more to improve. PVC and other plastics are very hard to assess by current ultrasonic methods. A new technique has been developed in the Wetsus Smart Water Grids research project Development of Inline Water Mains Inspection Technology, which makes this possible. The technique has been verified with single element transducers, however, extensive mechanical alignment is necessary to obtain good results. The use of the method is therefore possible in pipes with larger diameters and needs to be calibrated for a specific type of pipe. The use of actuator and receiver arrays eliminates the need for this mechanical alignment since this can be done with signal processing. This way, the method using phased arrays can be applied to pipes with varying diameter and varying composition.