Experimental and numerical simulation of shock waves generated by pulsed underwater electrical discharges

High power pulsed underwater electrical discharge can be used for different applications in medecine (destructions of kidney stones, decontamination of bacteria), industry (grinding of materials, forming, etc.) and recycling of multi-material wastes (separation and fragmentation of materials).

An electric arc between two electrodes creates a plasma channel generating a pressure wave which propagates into water. This wave is followed by expansion of a gaseous volume of water vapor. The amplitude of the shock wave depends on the electrical generator parameters, electrodes geometry, distance between them etc., and can be varied to obtain desired physical effects. Velocity measurements and Shlieren technique allow to visualize the waves propagation and characterize the shock waves and vapor bubble evolution. The experimental results are compared with corresponding RADIOSS numerical simulations in order to assess the code ability to physically reproduce this ultra-short high-intense phenomenon. After calibration, we utilized the series of simulations to analyze the mechanical and structural effects into objects placed in the water not far from the electrodes. The numerical modeling permit to design a new optimized concept for shock generation yielding to an improved efficiency in multi-material separation and fragmentation.

 

The Author

Dr. Ekaterina Mazanchenko
Post doc
PPRIME Institute - ISAE-ENSMA