Impact of Particle Characteristics and Engine Conditions on Deposit-Induced Preignition and Superknock in Turbocharged Gasoline Engines

Paper #:
  • 2017-01-2345

Published:
  • 2017-10-08
Abstract:
Low Speed Pre-Ignition (LSPI), also referred to as Superknock or Megaknock is an undesirable turbocharged engine combustion phenomenon limiting fuel economy, drivability, emissions and durability performance. Numerous researchers have previously reported that the frequency of Superknock is sensitive to engine oil and fuel composition as well as engine conditions in controlled laboratory and engine-based studies. Recent studies by Toyota and Tsinghua University have demonstrated that controlled induction of particles into the combustion chamber can induce preignition and superknock. Afton and Tsinghua recently developed a multi-physics approach which was able to realistically model all of the elementary processes known to be involved in deposit induced pre-ignition. The approach was able to successfully simulate deposit induced pre-ignition at conditions where the phenomenon has been experimentally observed. This tool allowed characterization of the impact of particle characteristics, bulk charge properties and engine conditions and provided valuable insight into behavior observed in engine and bench tests. In this work, multi-physics simulations were conducted that incorporated accurate representation of heat and mass transfer, particle oxidation and gas-phase autoignition and specific characteristics of the particle that dominate preignition were identified. The study was extended to simulate the effect of bulk charge properties and engine conditions on preignition and superknock. The results show that preignition timing, and therefore superknock, is particularly sensitive to key deposit characteristics. The results of this study help elucidate the phenomenon of deposit induced preignition that has been reported but is not well understood. Furthermore, the results of this study will aid the industry in development of improved fluid formulations and engine design that are needed to suppress superknock in real-world turbocharged engines.
Also in:
  • SAE International Journal of Fuels and Lubricants - V127-4
  • SAE International Journal of Fuels and Lubricants - V126-4
  • SAE International Journal of Fuels and Lubricants - V126-4EJ
Sector:
Topic:
Access
Now
SAE MOBILUS Subscriber? You may already have access.
Buy
Attention: This item is not yet published. Pre-Order to be notified, via email, when it becomes available.
Select
Price
List
Download
$27.00
Mail
$27.00
Members save up to 40% off list price.
Share
HTML for Linking to Page
Page URL

Related Items

Standard
1987-02-01
Standard
1966-08-01
Video
2017-02-03