Efficient Shock Wave Coupling to a Waveguide

High-voltage induced shock waves were created in different shaped spark chambers. The generated shock waves were imaged after they had traveled through a waveguide. Imaging was done by using a stroboscopic schlieren method to determine the speed of the shock wave in air. The effect of the spark chamber shape as well as the effect of the width of the spark gap were studied. The simple cylindrical chamber had the highest efficiency of the measured geometries. A wider spark gap resulted in a higher overpressure of the shock wave.Peer reviewe

Optimizing the Shock Wave-To-Vortex Power Ratio at the End of a Waveguide

Shock waves and vortices are two different ways of transferring acoustic energy to a sample in a contactless manner. This study aims at understanding the power ratio between shock waves and vortices as they exit a wave guide. Diverging tube ends increased the ratio, whereas converging ones decreased it. The power ratios were 0.1 to 9.8. Schlieren imaging was used to quantify the power-ratios. Altering the curvature at the end of the waveguide allows optimization of the shock wave-to-vortex power ratio at the end of a waveguide.Peer reviewe

Affordable and Wireless Transducer Network to Detect Fouling in Pipes

Localizing fouling in industrial pipes by AI-enhanced ultrasonic means shows promising results. However, the existing methods require large quantities of data measured from multiple locations and thus are either costly due to the number of transducers required or are hampered by readout uncertainties due to reattachment of the sensors. We present a wireless and affordable network of custom-built clamp-on transducers with drive electronics, in which transducers can be used as both transmitters and receivers. The network was used to generate and characterize propagating waves in pipes with and without fouling. The transducers and their driving electronics generate signals with sufficient signal-to-noise ratio in a repeatable manner and are sensitive enough to detect the signal change caused by fouling on a steel pipe.Peer reviewe