Date of Award


Publication Type

Master Thesis

Degree Name



Mechanical, Automotive, and Materials Engineering

First Advisor

Zheng, M.


Corona discharge, Ignition capability, Plasma length, Spark ignition




Advanced spark ignition (SI) engines may better operate under lean or diluted conditions for fuel efficiency improvement. Under lean or diluted conditions, the ignition and complete combustion of the mixture is a challenge with conventional spark plugs. The small spark gap with limited spark energy delivery and the associated heat loss to the ground electrode, remain to be an unsolved problem. This research explores the corona discharge as an alternative ignition technology to counter the challenges of lean or diluted combustion, including the intensive gas flow condition. Without an adjacent ground electrode, the corona discharge tends to generate a larger ignition volume and multiple flame kernels. The study is based on an in-house designed alternating-current (AC) corona system with adjustable electrical parameters. By controlling stable corona discharge, the plasma length is characterized, including the effects of discharge voltage, discharge duration, discharge frequency, and background conditions on corona discharge. Subsequently, ignition research is conducted to combustible mixtures, in constant volume chambers, to demonstrate the ignition capability of corona discharge under both quiescent and forced flow conditions. The preliminary test results of plasma-enhanced combustion are discussed to help future studies on clean combustion innovations.