(369c) Mathematical Modeling of Electrical Discharges in Liquid Water: The Chemistry Inside the Plasma Channel

A 3D mathematical model describing chemical reactions inside a cylindrical plasma channel formed during an electrical discharge in water has been developed. The model couples charge conservation equation for a RLC circuit with the thermal and mass energy balances for the duration of one plasma pulse. Chemical reactions scheme assumes that water molecules inside the plasma are dissociated by both electron impact dissociation and thermal water splitting. Numerical results indicate that for the applied voltage of 45 kV the temperature inside a plasma channel with a radius of 50 μm reaches a maximum temperature of 3500 K. In the absence of electron impact dissociation of water molecules, molecular hydrogen and oxygen are produced in a 2:1 ratio. At the same time, the concentration of hydrogen peroxide is almost negligible. The inclusion of electron reactions lowers the concentration of molecular oxygen and increases the production rate of hydrogen peroxide. With respect to the initial reactions of water dissociation, electron reactions, especially vibrational and rotational excitation, are far more significant than the thermal decomposition of water molecules.