Biomedical subjects

Ya E Krasik

Publications and source records attributed to Ya E Krasik.

3 recordsLinked to original sources

PubMed2006

Generation of sub-Mbar pressure by converging shock waves produced by the underwater electrical explosion of a wire array.

We report a demonstration of a generation of sub-Mbar pressure on the axis of the implosion wave produced by an underwater electrical explosion of a cylindrical wire array. The array was exploded by microsecond time scale discharge of a capacitor bank having a stored energy of 4.5 kJ and discharge current amplitude of up to 90 kA. Optical diagnostics were used to determine the time of flight and the trajectory of the converging shock wave. This data were applied for a calculation of the water flow parameters using one-dimensional (1D) and 2D hydrodynamic calculations and the Whitham method. All three methods have shown that the shock wave pressure at 0.1 mm from the axis reaches .

Journal Article↗

PubMed2005

Strongly coupled copper plasma generated by underwater electrical wire explosion.

A number of theoretical approaches to the analysis of the parameters of a discharge channel consisting of strongly coupled plasma generated in the process of underwater electrical wire explosion are presented. The analysis is based on experimental results obtained from discharges employing Cu wire. The obtained experimental data included electrical measurements and optical observations from which information about the dynamics of the water flow was extrapolated. Numerical calculation based on a 1D magnetohydrodynamic model was used to simulate the process of underwater wire explosion. A wide range conductivity model was applied in this calculation and good agreement with a set of experimental data was obtained. A method of determining the average temperature of the discharge channel based on this model and experimental results is proposed, and the limits of this method's applicability are discussed.

Journal Article↗

PubMed2004

Simplified model of underwater electrical discharge.

A model of the underwater discharge with initiating wire is presented. The model reveals the nature of similarity parameters which have been phenomenologically introduced in earlier experimental research in order to predict behavior of different discharges. It is shown that these parameters naturally appear as a result of the normalization of differential equations, which determines the process of underwater wire initiated discharge. In these equations the energy conservation law for wire material evaporation and the dependence of plasma conductivity on the energy dissipated in the discharge are implied to calculate the time varying resistance of the discharge gap. The comparison of calculations with the experimental results shows that good agreement is achieved when modification of these parameters is introduced. These new similarity parameters are functions of the original similarity parameters, hence the law of the similarity of underwater electrical discharge is preserved.

Journal Article↗