Spark Plasma Stretching and Ignition Improvement via High Frequency Pulsed Current Boost

Abstract

Article Spark Plasma Stretching and Ignition Improvement via High Frequency Pulsed Current Boost Linyan Wang , Xiao Yu , Zhi Yang Ong , Simon LeBlanc , and Ming Zheng ,* Department of Mechanical, Automotive and Materials Engineering, University of Windsor, 401 Sunset Avenue, Windsor, N9B 3P4 Ontario, Canada * Correspondence: mzheng@uwindsor.ca     Received: 9 May 2023 Accepted: 12 May 2023 Published: 19 June 2023   Abstract: In modern engines, the improvement of fuel efficiency and reduction of exhaust emissions have become increasingly important, with the consequent need for improved performance and advancement of ignition systems. The ignition mechanisms utilized in modern engines frequently encounter a fuel-lean or gas-diluted blend of substantial density and vigorous airflow. Under such conditions, the spark plasma is influenced by gas movements, specifically crossflows that occur in a voluminous manner. The gas motions can stretch the plasma channel, thereby amplifying the total discharge energy compared to quiescent conditions. It has been proven that an increased discharge current is an efficacious method for extending the duration of spark plasma stretching. Nevertheless, high discharge current can increase the energy consumption of ignition systems and consequently, influence the durability and overall energy efficiency of the system. Moreover, the persistent flow of intense electrical current leads to prompt erosion of the spark electrode, impacting the durability of the spark plug. In this study, a novel ignition strategy of high-frequency pulsed currents is introduced, to enhance the effectiveness of plasma stretching and energy discharge while minimizing the overall energy usage of ignition systems. A high-frequency pulsed discharge strategy is accomplished within the controlled duration without affecting the plasma stretching phenomenon. The plasma channel behaviors are logged using electrical and optical measurements. Furthermore, the discharge frequency and current level impacts of the boosted current pulses on the plasma stretching behavior and flame propagation are also investigated.