Effects of pre-spark heat release on engine knock limit

Splitter, Derek A.; Gilliam, Arthur; Szybist, James; Ghandhi, Jaal

doi:10.1016/j.proci.2018.05.145

Title: Effects of pre-spark heat release on engine knock limit

Abstract

It is well known that spark ignited engine efficiency is limited by end gas autoignition, commonly known as knock. This study focuses on a recently discovered phenomena, pre-spark heat release (PSHR) due to low-temperature chemistry, and its impact on knock behavior. Boosted operating conditions are more common as engines are downsizing and downspeeding in efforts to increase fuel economy and prone to PSHR. Experiments were prone at fixed fueling and air fuel ratio for a range of intake temperature that spanned the threshold for PSHR. It was found that when PSHR occurred, the knock-limited combustion phasing was insensitive to intake temperature; higher intake temperatures did not require retarded timings as it is usual. Inspection of the temperature–pressure history overlaid on ignition delay contours allow the results to be explained. The temperature rise from the low-temperature reactions moves the end gas state into the negative temperature coefficient (NTC) region, which terminates the heat release reactions. As a result, the end gas then resides in the long ignition delay peninsula, which inhibits knock.

Authors:

; Gilliam, Arthur;

; Ghandhi, Jaal

Publication Date:: Tue Jan 01 00:00:00 EST 2019

Research Org.:: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

Sponsoring Org.:: USDOE Office of Energy Efficiency and Renewable Energy (EERE)

OSTI Identifier:: 1457510

Alternate Identifier(s):: OSTI ID: 1468233

Grant/Contract Number:: AC05-00OR22725

Resource Type:: Published Article

Journal Name:: Proceedings of the Combustion Institute

Additional Journal Information:: Journal Name: Proceedings of the Combustion Institute Journal Volume: 37 Journal Issue: 4; Journal ID: ISSN 1540-7489

Publisher:: Elsevier

Country of Publication:: United States

Language:: English

Subject:: 42 ENGINEERING; SI Engines; Knock; Low temperature chemistry; Pre spark heat release; Chemical kinetics

Citation Formats


                    Splitter, Derek A., Gilliam, Arthur, Szybist, James, and Ghandhi, Jaal. Effects of pre-spark heat release on engine knock limit.  United States: N. p., 2019. 
Web.  doi:10.1016/j.proci.2018.05.145.

Copy to clipboard


                    Splitter, Derek A., Gilliam, Arthur, Szybist, James, & Ghandhi, Jaal. Effects of pre-spark heat release on engine knock limit.  United States.  https://doi.org/10.1016/j.proci.2018.05.145

Copy to clipboard


                    Splitter, Derek A., Gilliam, Arthur, Szybist, James, and Ghandhi, Jaal. Tue .  
"Effects of pre-spark heat release on engine knock limit".  United States.  https://doi.org/10.1016/j.proci.2018.05.145.

Copy to clipboard


                    
@article{osti_1457510,

  title        = {Effects of pre-spark heat release on engine knock limit},

  author       = {Splitter, Derek A. and Gilliam, Arthur and Szybist, James and Ghandhi, Jaal},

  abstractNote = {It is well known that spark ignited engine efficiency is limited by end gas autoignition, commonly known as knock. This study focuses on a recently discovered phenomena, pre-spark heat release (PSHR) due to low-temperature chemistry, and its impact on knock behavior. Boosted operating conditions are more common as engines are downsizing and downspeeding in efforts to increase fuel economy and prone to PSHR. Experiments were prone at fixed fueling and air fuel ratio for a range of intake temperature that spanned the threshold for PSHR. It was found that when PSHR occurred, the knock-limited combustion phasing was insensitive to intake temperature; higher intake temperatures did not require retarded timings as it is usual. Inspection of the temperature–pressure history overlaid on ignition delay contours allow the results to be explained. The temperature rise from the low-temperature reactions moves the end gas state into the negative temperature coefficient (NTC) region, which terminates the heat release reactions. As a result, the end gas then resides in the long ignition delay peninsula, which inhibits knock.},

  doi          = {10.1016/j.proci.2018.05.145},

  journal      = {Proceedings of the Combustion Institute},

  number       = 4,

  volume       = 37,

  place        = {United States},

  year         = {Tue Jan 01 00:00:00 EST 2019},

  month        = {Tue Jan 01 00:00:00 EST 2019}

}

Copy to clipboard

Journal Article:

Free Publicly Available Full Text

Publisher's Version of Record
https://doi.org/10.1016/j.proci.2018.05.145

Other availability

Search WorldCat to find libraries that may hold this journal

Citation Metrics:

Cited by: 15 works

Citation information provided by
Web of Science

Save / Share:

Export Metadata

Save to My Library

Works referencing / citing this record:

Green pathway to a new fuel extender: continuous flow catalytic synthesis of butanol/butyl butyrate mixtures
journal, January 2020

Scotti, Nicola; Ravasio, Nicoletta; Zaccheria, Federica
RSC Advances, Vol. 10, Issue 6
DOI: 10.1039/d0ra00198h

Similar Records in DOE PAGES and OSTI.GOV collections:

Modeling Pre-Spark Heat Release and Low Temperature Chemistry of Iso-Octane in a Boosted Spark-Ignition Engine

Conference Delvescovo, Dan ; Splitter, Derek ; Szybist, James

Recent trends among automotive manufacturers towards downsized, boosted engines make it imperative to understand specific fuel chemistry interactions encountered in this new operating regime. At these elevated pressure conditions a phenomenon called pre-spark heat release (PSHR) has recently been discovered, characterized by kinetically controlled heat release before spark, leading to changes in end-gas thermodynamic state and composition. These reactions typically occur in the end-gas during normal operation, but are obscured by the deflagration heat release, and therefore cannot be easily studied. A 2-zone spark-ignition engine model was utilized to determine whether chemical kinetic mechanisms predict this phenomenon, and whether theymore »« less
https://doi.org/10.1016/j.combustflame.2019.10.009

Full Text Available
CFD modeling of pre-spark heat release in a boosted direct-injection spark-ignition engine

Journal Article Guo, Hengjie ; Torelli, Roberto ; Szybist, James P. ; ... - International Journal of Engine Research

Accurate predictions of low-temperature heat release (LTHR) are critical for modeling auto-ignition processes in internal combustion engines. While LTHR is typically obscured by deflagration, extremely late ignition phasing can lead to LTHR prior to the spark, a behavior known as pre-spark heat release (PSHR). In this research, PSHR in a boosted direct-injection spark-ignition engine was studied using 3-D computational fluid dynamics (CFD) and detailed chemical kinetics. The turbulent combustion was modeled via a hybrid approach that incorporates the G-equation model for tracking the turbulent flame front, and the well-stirred reactor model with detailed chemistry for assessing the low-temperature reactions inmore »« less
https://doi.org/10.1177/14680874211044110
Fuel Kinetic Effects on Pre-Spark Heat Release and Engine Knock Limit

Conference Gilliam, Arthur ; Splitter, Derek ; Szybist, James ; ...

This study focuses on the ability of chemical mechanisms to describe the recently discovered phenomena of pre-spark heat release (PSHR) due to low-temperature chemistry. Experiments were conducted at fixed air and fuel flow rates for a range of intake temperature that spanned the threshold for PSHR. It was found that when PSHR occurred, the knock-limited combustion phasing was insensitive to intake temperature. A three-zone model using full chemistry was used to investigate the phenomenon with both a detailed and skeletal chemical kinetic mechanism. Both mechanisms predicted the presence of PSHR. The skeletal mechanism was found to more faithfully reproduce themore »« less
Full Text Available
Modeling pre-spark heat release and low temperature chemistry of iso-octane in a boosted spark-ignition engine

Journal Article DelVescovo, Dan A. ; Splitter, Derek A. ; Szybist, James P. ; ... - Combustion and Flame

Recent trends among automotive manufacturers towards downsized, boosted engines make it imperative to understand specific fuel chemistry interactions encountered in this new operating regime. At these elevated pressure conditions a phenomenon called pre-spark heat release has recently been discovered, and is characterized by kinetically controlled heat release before spark, with resultant changes in end-gas thermodynamic state and composition. These reactions typically occur in the end-gas during normal operation, but are obscured by the deflagration heat release and therefore cannot be easily studied. A 2-zone spark-ignition engine model was utilized to determine whether chemical kinetic mechanisms are able to predict thismore »« less
Cited by 11
https://doi.org/10.1016/j.combustflame.2019.10.009
Engine Operating Conditions and Fuel Properties on Pre-Spark Heat Release and SPI Promotion in SI Engines

Conference Splitter, Derek ; Kaul, Brian ; Szybist, James ; ...

This work explores the dependence of fuel ignition delay on stochastic pre-ignition (SPI). Findings are based on bulk gas thermodynamic state, where the effects of kinetically controlled bulk gas pre-spark heat release (PSHR) are correlated to SPI tendency and magnitude. Specifically, residual gas and low temperature PSHR chemistry effects and observations are explored, which are found to be indicative of bulk gas conditions required for strong SPI events. Analyzed events range from non-knocking SPI to knocking SPI and even detonation SPI events in excess of 325 bar peak cylinder pressure. The work illustrates that singular SPI event count and magnitudemore »« less
https://doi.org/10.4271/2017-01-0688

Full Text Available

Similar Records

Title: Effects of pre-spark heat release on engine knock limit

Abstract

Citation Formats

Green pathway to a new fuel extender: continuous flow catalytic synthesis of butanol/butyl butyrate mixtures journal, January 2020

Green pathway to a new fuel extender: continuous flow catalytic synthesis of butanol/butyl butyrate mixtures
journal, January 2020