Shock waves in water are generated in a specially constructed plane chamber by the explosion of an electrically conductive wire by sudden discharge of energy stored in the capacitor. The high voltage capacitor has ratings of 6 microfarad capacitance and 30 kV voltage enabling maximum energy storage of 2.7 kJ. When the wire is subjected to sudden deposition of this energy, it gets super-heated thereby getting vaporized resulting in the generation of intense blast wave moving outwards of the explosion origin. Our interest lies in investigating the influence of this electrical energy delivered to the wire on the shock wave Mach number in water. The electrical energy delivered to the wire is dependent on the discharge voltage of the capacitor, rate of the discharging current, type of the wire and its size. The shock waves generated in water are channelized in a uniquely designed experimental test cell consisting of two chambers - Exploding Chamber (EC) and Test Chamber (TC) both comprising of 12 mm thick steel walls. The top and bottom wall of the TC is made up of 20 mm thick plexi-glass plates which are separated by a distance of 5mm to enable visualization of the propagating shock wave using Schlieren technique. Using this, the shock Mach number is measured using the time of flight method at different time instants. The efficiency of energy transfer from electrical to mechanical is investigated depending on experimental conditions. The most efficient mode is then used for generating blast waves in water. The primary goal is to study the shock induced bubble collapse phenomena with particular interest towards the basic mechanisms occurring during the underwater shock wave interaction with an air bubble, including shock wave interaction at the water/air interface, reflection, focusing and high speed liquid jetting. Hydrophobic coating technique is used on the plexi-glass plates to assist in shaping and maintaining the air bubble of the desired diameter and at the desired position in TC. Numerical studies are performed to compare the prediction with the experimental results.
