High Energy Multipole Distribution Spark Ignition System

This work presents a high energy multipole distribution spark ignition system that utilizes a three-pole spark igniter to create spatially distributed sparks within the igniter perimeter. The current prototype can fit in a M14 standard spark plug mounting thread, evenly distributing three spark gaps in a triangular pattern with a circumradius of 2.3 mm. The spark gaps can be individually energized by the attached ignition coils, thereby discharging in either simultaneous or alternating mode. The experimental results from both the single-cylinder engine and constant-volume combustion vessels indicate a clear trend that, on the basis of similar total spark energy levels, the three-pole ignition system can shorten the ignition delay, stabilize the combustion phasing, and extend the ignitable lean limits, compared to a conventional fine-electrode spark plug. Moreover, as found in the combustion vessel tests, the effectiveness of spark discharge enhancement using direct-capacitor discharge can be augmented through simultaneously discharging through the three poles, hence resulting in significantly shortened ignition delay.