NUMERICAL ANALYSIS OF THE TWO-FREQUENCY APPROACH TO DETERMINE TORCH DISCHARGE RESISTANCE WITH OR WITHOUT ITS EQUIVALENT INDUCTANCE BEING TAKEN INTO ACCOUNT
A. O. Puzanov · Telecommunications and Radio Engineering · 2018
The torch discharge (TD) is widely applied in a number of areas of science and technology. Considerable lag in theoretical research and rapidly growing needs are those factors that make the solution of many practical-oriented TD-related problems so relevant. In this paper, the author continues to explore his novel approach to measuring the TD resistance (Rd) taking into account the TD inductance L. The numerical calculations are supplemented by previously estimated application limits of this model. The sought resistance Rd is considered to be frequency independent within the theory. Performed estimations and calculations confirm the applicability of the approach presented, either with the TD inductance being taken into account or not, in the frequency range from 1·10-3 to 3.0 GHz. The study revealed that for TD of 1 kW or less it should be decided in every case individually whether to take the inductance in the account or not, and which two frequencies f0,1 are the proper choice for the measurement, and, if necessary, consider the feasibility of exciting similar TD at two quite different frequencies. When the inductance was neglected, the accuracy of Rd calculations proved to depend on the TD elevation above ground only slightly, and to rise significantly if TD diameter reduced, TD became longer, the measured Rd were small (< 1 kΩ), or f0,1 approach each other. In some cases, due to these reasons, the classical Neiman's scheme should inevitably be modified to include the equivalent inductance, thus the calculation formulae should be adapted respectively. It was shown that the resonance frequency fr of the discharge circuit is approximately proportional to frequency fmax, which is the upper limit of the frequency range where the circuit theory remains applicable for the discharge modeling, and fmax < fr . Thus, if fr and fmax are known, we can specify the possible values of function α, which is a ratio of voltages required for TD to maintain its electrical and geometrical characteristics. The suggested approach results in more effective using of industrial resources.