FEM Simulation of the temperature distribution and power density at platinum cathode craters caused by high voltage ignition discharges

Abstract

Craters caused by high voltage ignition discharges on the surface of materials are important features of the erosion processes of electrodes. In this paper, a thermal simulation of the crater formation on a platinum cathode is carried out by means of the finite element method (FEM). The model is based on the modelling of cathode spots and includes phenomena such as ion bombardment, electron emission, vaporization, melting and heat conduction. The surface of the cathode is submitted to various ion power densities (1010–1012 W m−2) of different durations (0.1, 1 and 10 µs) over a disc of a radius a = 10 µm. By comparing the results of the simulation with experimental data of molten depths and molten volumes, characteristic values of the time, the ion power density and the current involved in the crater formation are determined. These values are related to the electrical characteristic of an ignition discharge, permitting the identification of the phase producing the crater. Furthermore, the contribution of the different heat dissipation mechanisms is evaluated and discussed.

Experimental Study of Arc Discharge Induced Electrode Erosion and Its Influence on Arc Behaviors

“…[24]. Some literatures [25,26] present that the metal erosion rate should follow the Langmuir formula. The vapor temperature may be different from the electron temperature in the arc root area if considering the non-local thermal equilibrium [27,28].…”

Study of wall ablation on low-voltage arc interruption: The effect of Stefan flow

“…The added-in copper vapor helps to replenish the properties of plasma mixture in the simulation. Jeanvoine and Muecklich 18 used the finite element method to simulate the heat transfer and metal erosion, and presented the estimation of temperature distribution in the arc spot. This work proposed another approach to estimate the evaporation rate at the arc spot with Langmuir free evaporation theory; 18,19 however, his calculation was confined within a solid domain.…”

“…Jeanvoine and Muecklich 18 used the finite element method to simulate the heat transfer and metal erosion, and presented the estimation of temperature distribution in the arc spot. This work proposed another approach to estimate the evaporation rate at the arc spot with Langmuir free evaporation theory; 18,19 however, his calculation was confined within a solid domain. When it comes to wall ablation in LVCBs, Ruchti and Niemeyer 6 investigated the ablation controlled arcs in cylindrical tubes theoretically and experimentally, concluding that ablation plays a critical role in controlling pressure, and the ablation rate can be scaled by factors such as current, geometry, and materials.…”

Quantitative evaluation of the breakdown process of spark discharge for spark-ignition engines

“…The breakdown formation processes are mainly described by two mechanisms: the Townsend or avalanche multiplication mechanism and the streamer mechanism [13]. For low p • d values (<200 Torr • cm ≈ 2.67 bar • mm) [13], the breakdown processes are mainly dominated by the Townsend mechanism. For the Townsend mechanism, free electrons in the gap of the electrodes are forced to move by the electric field [14,15].…”