Active flow control for maximizing performance of spark ignited stratified charge engines. Final report

Fedewa, Andrew ; Stuecken, Tom ; Timm, Edward ; Schock, Harold J. ; Shih, Tom-I.P. ; Koochesfahani, Manooch ; Brereton, Giles

Engine Research Laboratory, Michigan State University, Okemos, MI (United States)

关键词: Spark Ignition Direct Injection;    Progress Report;    Computational Fluid Dynamics;    Intake Flow Control;    Variations;   

DOI  :  10.2172/809083
RP-ID  :  FC02-99EE50574
RP-ID  :  809083

美国|英语

来源: UNT Digital Library

【 摘 要 】

Reducing the cycle-to-cycle variability present in stratified-charge engines is an important step in the process of increasing their efficiency. As a result of this cycle-to-cycle variability, fuel injection systems are calibrated to inject more fuel than necessary, in an attempt to ensure that the engines fire on every cycle. When the cycle-to-cycle variability is lowered, the variation of work per cycle is reduced and the lean operating limit decreases, resulting in increased fuel economy. In this study an active flow control device is used to excite the intake flow of an engine at various frequencies. The goal of this excitation is to control the way in which vortices shed off of the intake valve, thus lowering the cycle-to-cycle variability in the flow field. This method of controlling flow is investigated through the use of three engines. The results of this study show that the active flow control device did help to lower the cycle-to-cycle variability of the in-cylinder flow field; however, the reduction did not translate directly into improved engine performance.