Examination of factors impacting unaccounted fuel post GDI fuel injector closing

Document Type

Technical Report

Publication Date



Department of Mechanical Engineering-Engineering Mechanics


The characteristics of gasoline sprayed directly into combustion chambers are of critical importance to engine out emissions and combustion system development. The optimization of the spray characteristics to match the in-cylinder flow field, chamber geometry, and spark location is a vital tasks during the development of an engine combustion strategy. Furthermore, the presence of liquid fuel during combustion in Spark-Ignition (SI) engines causes increased hydro-carbon (HC) emissions. Euro 6, LEVIII, and US Tier 3 emissions regulations reduce the allowable particu-late mass significantly from the previous standards. LEVIII standards reduce the acceptable particulate emission to 1 mg/mile. A good DISI strategy vaporizes the correct amount of fuel just in time for optimal power output with minimal emis-sions. The opening and closing phases of DISI injectors are crucial to this task as the spray produces larger droplets during both theses phases. This paper illustrates the preliminary results looking at how deposits on the injector tip, fuel type, and manufacturer affect the fuel characteristics during injector closing. The data was collected using a novel technique developed at Ford’s Powertrain and Fuel Subsystems Lab. The review will focus on the variation of droplet diameter and the mass post injector closing for a given injector.

Publisher's Statement

© 2018 SAE International; Ford Motor Co Ltd. Publisher’s version of record: https://doi.org/10.4271/2018-01-0300

Publication Title

SAE International