Experimental Study of Pulsed Discharge Underwater Shock‐Related Properties in Pressurized Liquid Water

Abstract

Engineering background of hydraulic fracturing is applied to improve the permeability of unconventional gas wells, such as coal seams and shale gas wells, by a pulsed discharge mechanism. We studied the general relations between water shock wave properties (the maximum pressure, wave velocity, and energy conversion efficiency), the discharge voltage, and hydrostatic pressure during high-voltage pulsed discharge experiments in pressurized liquid water. e following observations were made: (1) when the discharge voltage increased from 7 kV to 13 kV, the maximum pressure increased from 12.6 MPa (hydrostatic pressure P H � 12 MPa) to 40 MPa (P H � 6 MPa), wave velocity increased from 1418 m/s (P H � 12 MPa) to 1454 m/s (P H � 6 MPa), and energy conversion efficiency increased from 9% to 11%, and (2) when hydrostatic pressure increased from 0 MPa to 12 MPa, the maximum pressure and wave velocity augmented and then diminished slowly (the critical hydrostatic pressure occurs in the 3 to 6 MPa range), whereas the change of energy conversion efficiency was not obvious. eir properties are explained by the variation of electrical parameters during the pulsed discharge.

Enhancement of palm oil extraction yield by applying underwater shock wave pre-treatment at different voltage

“…From these, the maximum shock pressure was generated from the 10 kV discharge at 43.92 MPa. This pressure trend agrees well with previous works (Touya et al, 2006;Bian et al, 2018), showing the increase of shock pressure when voltage increases. This shock pressure was strong enough, and could lead to the cracking of the mesocarp structure as discussed in the next section.…”

Studying the effect of electrohydraulically treated soil solutions on plant growth and development

“…The pulse repetition frequency depends on the capacitance value of the capacitor, the applied voltage, and the size of the adjustable forming air gap. [7][8][9][10] The electrical circuit diagram of the installation is shown in Figure 3. Power is supplied to the circuit using the QF circuit breaker, which acts as a protective and starting device.…”

A Versatile Route for Synthesis of Metal Nanoalloys by Discharges at the Interface of Two Immiscible Liquids

“…The nanomaterials produced using the former type of discharges are strongly affected by both plasma-electrode and plasma-liquid interactions. In-liquid plasmas exhibit non-conventional properties of temperature (several thousands of Kelvin), pressure (several tens of bars), and density of charged species (10 17 –10 19 cm −3 ) over very short time scales (rise and decay time less than 1 µs) [ 21 , 22 , 23 , 24 ]. Moreover, the flexibility of in-liquid plasmas allows discharge ignition in different liquids (e.g., water, hydrocarbons, cryogenics, etc.)…”