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The goal of this work is to investigate arc quenching in electric vehicle relays using high-fidelity computational modeling. Rapid arc quenching is an essential quality of state-of-the-art high-voltage mechanical relays in electric vehicles. As a relay begins to break electrical contact, strong arcing can occur. This delays the process of sending a signal to the primary circuit breaker to isolate the load from a sudden current surge. The strength and duration of the arc have a significant impact on the safety of electric vehicles as well as on relay contactor erosion/lifetime. A thermal plasma modeling tool is used to estimate switch-off time in an arc relay using hydrogen and air as working gases. The response of arc dynamics and switch-off time to the gas composition, external magnetic field strength, and chamber pressure is studied. It was observed that a hermetically sealed chamber filled with hydrogen is significantly more efficient than air at quenching the arc.

The arc breakdown phase in automotive spark-plugs is a sub-microsecond event that precedes the main spark event. This phase is typically characterized by strong non-equilibrium plasma phenomena with high voltage and currents. The nature of the initial breakdown phase has strong implications for the successful spark formation and the electrode erosion/lifetime. There are evidently very few studies that seek to characterize this phase in detail. The goal of this work is to investigate this non-equilibrium plasma arc breakdown phase, using high-fidelity computational modeling. We perform studies using the VizGlow non-equilibrium plasma modeling tool. During the early breakdown phase, the plasma forms thin filamentary streamers that provide the initial conductive channel across the gap. Once the streamers bridge the gap, the plasma begins to transition to a thermal arc.

There has been an increased interest in understanding the initial stages of flame kernel formation in internal combustion engines as it offers a potential way of improving their thermal efficiency. For spark-ignited engines, the dynamics that govern the initial spark and its transition into a flame kernel play an important role in determining the overall engine efficiency. In this regard, this paper presents a computational model developed to simulate a spark discharge formed in a premixed fuel air mixture. Additionally, by simultaneously modeling the reactive fluid dynamics that governs combustion with the electromagnetics that governs the spark, the overall objective of this paper is to consistently simulate spark-initiated combustion in a premixed fuel-air mixture. Two different fuel-oxidizer mixtures are considered in this study, hydrogen-oxygen and methane-oxygen. Key mechanisms via which the spark channel ignites the mixture are identified and studied in detail.