scholarly journals Ultra Efficient Light Duty Powertrain with Gasoline Low Temperature Combustion

2019 ◽  
Author(s):  
Keith Confer
Keyword(s):  
Low Temperature ◽  
Low Temperature Combustion ◽  
Light Duty ◽  
Temperature Combustion

scholarly journals A Novel Fuel Performance Index for Low-Temperature Combustion Engines Based on Operating Envelopes in Light-Duty Driving Cycle Simulations

2015 ◽  
Vol 137 (10) ◽  
Author(s):  
Kyle E. Niemeyer ◽  
Shane R. Daly ◽  
William J. Cannella ◽  
Christopher L. Hagen
Keyword(s):  
Low Temperature ◽  
Performance Index ◽  
Test Procedure ◽  
Driving Cycle ◽  
Low Temperature Combustion ◽  
Fuel Performance ◽  
Light Duty ◽  
Auto Ignition ◽  
Temperature Combustion ◽  
Light Duty Vehicle

Low-temperature combustion (LTC) engine concepts such as homogeneous charge compression ignition (HCCI) offer the potential of improved efficiency and reduced emissions of nitrogen oxide (NOx) and particulates. However, engines can only successfully operate in HCCI mode for limited operating ranges that vary depending on the fuel composition. Unfortunately, traditional ratings such as octane number (ON) poorly predict the auto-ignition behavior of fuels in such engine modes, and metrics recently proposed for HCCI engines have areas of improvement when wide ranges of fuels are considered. In this study, a new index for ranking fuel suitability for LTC engines was defined, based on the fraction of potential fuel savings achieved in the federal test procedure (FTP-75) light-duty vehicle driving cycle. Driving cycle simulations were performed using a typical light-duty passenger vehicle, providing pairs of engine speed and load points. Separately, single-zone naturally aspirated HCCI engine simulations were performed for a variety of fuels in order to determine the operating envelopes for each. These results were combined to determine the varying improvement in fuel economy offered by fuels, forming the basis for a fuel performance index. Results showed that, in general, lower octane fuels performed better, resulting in higher LTC fuel index values; however, ON alone did not predict fuel performance.

UHC and CO Emissions Sources From a Light-Duty Diesel Engine Undergoing Late-Injection Low-Temperature Combustion

2009 ◽  
Author(s):  
Isaac W. Ekoto ◽  
William F. Colban ◽  
Paul C. Miles ◽  
Ulf Aronsson ◽  
O¨ivind Andersson ◽  
...  
Keyword(s):  
High Temperature ◽  
Diesel Engine ◽  
Low Temperature ◽  
Injection Timing ◽  
Spatial Distributions ◽  
Low Temperature Combustion ◽  
Light Duty ◽  
Temperature Heat ◽  
Temperature Combustion ◽  
Homogeneous Reactor

Low load carbon monoxide (CO) and unburned hydrocarbon (UHC) emissions sources are examined in an optically accessible, light-duty diesel engine employing a late-injection, low-temperature combustion strategy. The study focus is to identify the cause of the rapid degradation in emissions and efficiency as injection timing is retarded. The in-cylinder progression of mixing and combustion processes is examined through ultraviolet planar laser-induced fluorescence (UV PLIF) imaging of hydrocarbon spatial distributions. Spectrally-resolved, deep-UV LIF measurements are also used to construct late-cycle spatial distributions of CO, C2, and polycyclic aromatic hydrocarbons within the clearance volume. Engine-out emissions measurements and numerical results from both detailed chemistry homogeneous reactor and multidimensional simulations complement the measurements. The measured spatial distributions show that while most fuel accumulates on the bowl-pip during high-temperature heat-release, much of it is transported into the squish-volume by the reverse squish flow. Homogeneous reactor simulations further show that expansion cooling quenches reactions, preventing the transition to high-temperature heat-release for mixtures with an equivalence ratio below 0.6. Lean squish-volume mixtures, coupled with wall heat losses, severely inhibit squish volume fuel oxidation. Further retarding injection timing exacerbates quenching, resulting in a two-fold increase in UHC emissions and a 33% increase in CO, primarily from the squish-volume.

Fuel Effects on Low Temperature Combustion in a Light-Duty Diesel Engine

2010 ◽  
Author(s):  
Alok Warey ◽  
Jean-Paul Hardy ◽  
Manuela Hennequin ◽  
Marek Tatur ◽  
Dean Tomazic ◽  
...  
Keyword(s):  
Diesel Engine ◽  
Low Temperature ◽  
Low Temperature Combustion ◽  
Light Duty ◽  
Temperature Combustion ◽  
Fuel Effects
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