The device is used to electrically explode the conducting wire of up to 11cmlength of 250 micron diameter in underwater conditions. A pressure pulse is generated inside the water which decays with empirical law of (distance)^-0.7 from the metal wire. The pressures at 5cm are expected to be ~100Mpa. At close distances the pressures are still higher in amplitude.The system is tested to be working in the saline water which has salinity level to that of near sea water. The discharge is done in sub-microsecond duration in order to mitigate any considerable shunting possibility of electrical energy through the water instead of desired path of the energy deposition. The dimensions are restricted to 115mmin radius and 1.6m in length for single shot application. The weight of the pressure wave generator without any external housing is 40 kgs. The wire is presently clamped between the nut-bolted output connections points which are accessible from outside of the system.

APPLICATIONS

• For the generation of pressure/shock waves in underwater/liquid conditions.
• For the production of metal nano-powder.
• For the study of metal phase transition at faster di/dt rate through solid-liquid vapor and plasma states.
• Food tenderization studies.
• Packaging survivability testing under pressure wave loading.

SPECIFICATIONS

This pulsed plasma based pressure/shock wave generator offers advantages that it is electrically driven and highly efficient in terms of electrical energy. More over the System is compact and portable. The generator is high voltage insulated and can work in saline water also. The pressure generated are controlled which do not exceed the ultimate breakdown strength of steel but still beyond the plastics. The high pressures generated are confined in space near exploding conductor. So basic high voltage and high pressure safety is included in the designing and developing the shock wave generator.

PRINCIPLE OF OPERATION

The electrical energy is dissipated in to the metal wire which undergoes transitions from solid to liquid and then to the vapor state. In the vapor state, the resistivity and the rate of rise of resistivity is quite high as further energy is dissipated into the metal wire. This rapid rate of rise of resistivity causes the formation of high temperature high velocity expanding metal plasma which interacts through surrounding media for the generation of strong pressure pulse especially in underwater condition.

FACILITIES AND MANPOWER REQUIRED FOR COMMERCIAL PRODUCTION

1. Laptop + digitizer or oscilloscope to monitor the discharge pulses. (250MHz or higher bandwidth and 1Gsa/s or higher sampling rate)
2. Rogowski coil/high bandwidth current transformer and High Voltage probe with multimeter.
3. Electronic soldering, assembling and testing facility
4. A good mechanical workshop with facility of milling, drilling, bending, cutting buffing for fabrication of various mounts and chassis of the system. For the placement and mechanical ruggedness of the device the Epoxy molding should also be there.
5. High Voltage Safety equipments are also required.
6. One electrical and one mechanical diploma person with experience in pressure testing and high voltage testing may be required for the production and operation of the equipment.