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.

scholarly journals A novel fuel performance index for low-temperature combustion engines based on operating envelopes in light-duty driving cycle simulations

2016 ◽  
Author(s):  
Kyle Evan Niemeyer ◽  
Shane Daly ◽  
William Cannella ◽  
Christopher 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.

A Novel Fuel Performance Index for LTC Engines Based on Operating Envelopes in Light-Duty Driving Cycle Simulations

2014 ◽  
Author(s):  
Kyle E. Niemeyer ◽  
Shane R. Daly ◽  
William J. Cannella ◽  
Christopher L. Hagen
Keyword(s):  
Performance Index ◽  
Octane Number ◽  
Driving Cycle ◽  
Low Temperature Combustion ◽  
Fuel Performance ◽  
Fuel Savings ◽  
Light Duty ◽  
Hcci Engines ◽  
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 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 poorly predict the autoignition 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 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, octane number alone did not predict fuel performance.

scholarly journals Investigation of the LTC fuel performance index for oxygenated reference fuel blends

2016 ◽  
Author(s):  
Kyle Evan Niemeyer ◽  
Shane Daly ◽  
William Cannella ◽  
Christopher Hagen
Keyword(s):  
Performance Index ◽  
Engine Speed ◽  
Driving Cycle ◽  
Fuel Performance ◽  
Fuel Blend ◽  
Fuel Savings ◽  
Fuel Blends ◽  
Light Duty ◽  
Octane Rating ◽  
Light Duty Vehicle

A new metric for ranking the suitability of fuels in LTC engines was recently introduced, based on the fraction of potential fuel savings achieved in the FTP-75 light-duty vehicle driving cycle. In the current study, this LTC fuel performance index was calculated computationally and analyzed for a number of fuel blends comprised of n-heptane, isooctane, toluene, and ethanol in various combinations and ratios corresponding to octane numbers from 0 to 100. In order to calculate the LTC index for each fuel, computational driving cycle simulations were first performed using a typical light-duty passenger vehicle, providing pairs of engine speed and load points. Separately, for each fuel blend considered, single-zone naturally aspirated HCCI engine simulations with a compression ratio of 9.5 were performed in order to determine the operating envelopes. These results were combined to determine the varying improvement in fuel economy offered by fuels, forming the basis for the LTC fuel index. The resulting fuel performance indices ranged from 36.4 for neat n-heptane (PRF0) to 9.20 for a three-component blend of n-heptane, isooctane, and ethanol (ERF1). For the chosen engine and chosen conditions, in general lower-octane fuels performed better, resulting in higher LTC fuel index values; however, the fuel performance index correlated poorly with octane rating for less-reactive, higher-octane fuels.

An Experimental Investigation of the Auto-Ignition Properties of Two C5 Esters: Methyl Butanoate and Butyl Methanoate

2007 ◽  
Author(s):  
Stephen M. Walton ◽  
Carlos Perez ◽  
Margaret S. Wooldridge
Keyword(s):  
Low Temperature ◽  
High Speed ◽  
Combustion Engine ◽  
Low Temperature Combustion ◽  
Moderate Pressure ◽  
Molecular Weights ◽  
Auto Ignition ◽  
Methyl Butanoate ◽  
Temperature Combustion ◽  
Time Histories

Ignition studies of two small esters were performed using a rapid compression facility (RCF). The esters (methyl butanoate and butyl methanoate) were chosen to have matching molecular weights, and C:H:O ratios, while varying the lengths of the constituent alkyl chains. The effect of functional group size on ignition delay time was investigated using pressure time-histories and high speed digital imaging. The mixtures studied covered a range of conditions relevant to oxygenated fuels and fuel additives, including bio-derived fuels. Low temperature and moderate pressure conditions were selected for study due to their relevance to advanced low temperature combustion strategies, and internal combustion engine conditions. The results are discussed in terms of the reaction pathways affecting the ignition properties.

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