Date of Award

5-11-2018

Degree Type

Thesis

Degree Name

M.A.Sc.

Department

Mechanical, Automotive, and Materials Engineering

First Advisor

Zheng, Ming

Second Advisor

Xu, Xiaohong

Keywords

Dual-coil offset discharge, Energy transfer efficiency, Single-coil single discharge, Spark energy, Spark ignition, Transistor coil ignition

Rights

CC-BY-NC-ND

Abstract

The ever-growing demands to meet the exhaust emission regulations and fuel economy requirements have driven the development of modern spark ignition (SI) engines towards lean/diluted combustion strategies and engine downsizing. Currently, the transistor coil ignition (TCI) system is still the dominant ignition system applied in SI engines. However, the new development in SI engines demands higher spark energy and longer discharge duration to overcome the unfavorable ignition conditions caused by the diluted in-cylinder charge and the increased back pressure. Under these circumstances, higher energy transfer efficiency of the ignition system is also desirable. Therefore, this work investigates the factors that affect the spark energy and transfer efficiency of the TCI system. The primary current, discharge current and spark gap voltage of the TCI system under the single-coil single discharge and dual-coil offset discharge strategy were measured. Based on the measurement, the spark energy and transfer efficiency were calculated. A numerical model was developed and demonstrated the capability to estimate the trend of spark energy and transfer efficiency of the TCI system. The model was then used to systematically analyze the effects of coil inductance and charging duration/frequency on the spark energy and transfer efficiency of the TCI system.

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