Umashankar Joshi

Wayne State University

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Naeim A. Henein

Wayne State University

Ziliang Zheng

Inner Mongolia Electric Power (China)

Eric Sattler

United States Army

Peter Schihl

United States Army Combat Capabilities Development Command

Amit Shrestha

Wayne State University

Walter Bryzik

Wayne State University

Chandrasekharan Jayakumar

Wayne State University

Tamer Badawy

Wayne State University

Amit Shrestha

Tribhuvan University

Manan Trivedi

Wayne State University

Cooperative Institutions

Wayne State University

United States Army

United States Army Combat Capabilities Development Command

United States Department of the Army

U.S. Army Combat Capabilities Development Command Ground Vehicle System Center

China Automotive Technology and Research Center

Tribhuvan University

MorphoSys (Germany)

King Edward Memorial Hospital and Seth G.S. Medical College

Nirma University

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An Investigation on Sensitivity of Ignition Delay and Activation Energy in Diesel Combustion

Umashankar Joshi Ziliang Zheng Amit Shrestha Naeim A. Henein Eric Sattler

The auto-ignition process plays a major role in the combustion, performance, fuel economy and emission in diesel engines. The auto-ignition quality of different fuels has been rated by its cetane number (CN) determined in the CFR engine, according to ASTM D613. More recently, the Ignition Quality Tester (IQT), a constant volume vessel, has been used to determine the derived cetane number (DCN) to avoid the elaborate, time consuming and costly engine tests, according to ASTM D6890. The ignition delay period in these two standard tests and many investigations has been considered to be the time period between start of injection (SOI) and start of combustion (SOC). The ignition delay (ID) values determined in different investigations can vary due to differences in instrumentation and definitions. This paper examines the different definitions and the parameters that effect ID period. In addition the activation energy dependence on the ID definition is investigated. Furthermore, results of an experimental investigation in a single-cylinder research diesel engine will be presented while the charge density is kept constant during the ID period. The global activation energy is determined and its sensitivity to the charge temperature is examined.

Cetane number

Ignition timing

10.1115/icef2014-5587

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Citations (3)

Effect of Inlet Air Temperature on Auto-Ignition of Fuels With Different Cetane Number and Volatility

Chandrasekharan Jayakumar Ziliang Zheng Umashankar Joshi Walter Bryzik Naeim A. Henein

This paper investigates the effect of air inlet temperature on the auto-ignition of fuels that have different CN and volatility in a single cylinder diesel engine. The inlet air temperature is varied over a range of 30°C to 110°C. The fuels used are ultra-low-sulfur-diesel (ULSD), JP-8 (two blends with CN 44.1 & 31) and F-T SPK. Detailed analysis is made of the rate of heat release during the ignition delay period, to determine the effect of fuel volatility and CN on the auto-ignition process. A STAR-CD CFD model is applied to simulate the spray behavior and gain more insight into the processes that immediately follow the fuel injection including evaporation, start of exothermic reactions and the early stages of combustion. The mole fractions of different species are determined during the ignition delay period and their contribution in the auto-ignition process is examined. Arrhenius plots are developed to calculate the global activation energy for the auto-ignition reactions of these fuels. Correlations are developed for the ID and the mean air temperature and pressure.

Cetane number

Exothermic reaction

Minimum ignition energy

Autoignition temperature

Ultra-low-sulfur diesel

10.1115/icef2011-60141

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Citations (10)

Effect of Intake Pressure and Temperature on Auto-Ignition of Fuels with Different Cetane Number and Volatility

Eric Sattler Chandrasekharan Jayakumar Umashankar Joshi Zhaolei Zheng Walter Bryzik

Cetane number

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Citations (1)

Quantification Of Auto-Ignition In Diesel Engines

Umashankar Joshi

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Citations (0)

Effect of Cetane Improver on Combustion and Emission Characteristics of Coal-Derived Sasol IPK in a Single Cylinder Diesel Engine

Ziliang Zheng Umashankar Joshi Naeim A. Henein Eric Sattler

Sasol IPK is a coal-derived synthetic fuel under consideration as a blending stock with JP-8 for use in military ground vehicles. Since Sasol IPK is a low ignition quality fuel with Derived Cetane Number (DCN) of 31, there is a need to improve its ignition quality. This paper investigates the effect of adding different amounts of Lubrizol 8090 cetane improver to Sasol IPK on increasing its DCN. The experimental investigation was conducted in a single-cylinder research type diesel engine. The engine is equipped with a common rail injection system and an open Engine Control Unit (ECU). Experiments covered different injection pressures and intake air temperatures. Analysis of test results was made to determine the effect of cetane improver percentage in the coal-derived Sasol IPK blend on autoignition, combustion and emissions of carbon monoxide (CO), total unburned hydrocarbon (HC), oxides of nitrogen (NOx), and particulate matter (PM). In addition, the effect of cetane improver on the apparent activation energy of the global autoignition reactions was determined.

Cetane number

Autoignition temperature

10.1115/icef2014-5589

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Citations (6)

Experimental Validation and Combustion Modeling of a JP-8 Surrogate in a Single Cylinder Diesel Engine

SAE 2014 World Congress & ExhibitionSAE International (2014)

Amit Shrestha Umashankar Joshi Ziliang Zheng Tamer Badawy Naeim A. Henein

Abstract : Experimental Validation: At the test conditions analyzed, the two-component S2 surrogate fairly reproduced the following characteristics of the target JP-8: -Ignition delays -Pressure, RHR, mass-averaged gas temperature -Engine-out emissions (CO, HC, NOX), with an exception of the absolute PM values. 3D CFD Simulation: -The simulation results were in fairly good agreement with the experimental data for the surrogate. The two-component S2 surrogate could be a reasonable choice for its use in further investigations on the target JP-8.

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Effect of Cetane Improver on Combustion and Emission Characteristics of Coal-Derived Sasol Isomerized Paraffinic Kerosene in a Single Cylinder Diesel Engine

Journal of Engineering for Gas Turbines and Power (2014)

Ziliang Zheng Umashankar Joshi Naeim A. Henein Eric Sattler

Sasol isomerized paraffinic kerosene (IPK) is a coal-derived synthetic fuel under consideration as a blending stock with JP-8 for use in military ground vehicles. Since Sasol IPK is a low ignition quality fuel with derived cetane number (DCN) of 31, there is a need to improve its ignition quality. This paper investigates the effect of adding different amounts of Lubrizol 8090 cetane improver to Sasol IPK on increasing its DCN. The experimental investigation was conducted in a single cylinder research type diesel engine. The engine is equipped with a common rail injection system and an open engine control unit. Experiments covered different injection pressures and intake air temperatures. Analysis of test results was made to determine the effect of cetane improver percentage in the coal-derived Sasol IPK blend on auto-ignition, combustion and emissions of carbon monoxide (CO), total unburned hydrocarbon (HC), oxides of nitrogen (NOx), and particulate matter (PM). In addition, the effect of cetane improver on the apparent activation energy of the global auto-ignition reactions was determined.

Cetane number

Kerosene

Autoignition temperature

10.1115/1.4029207

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Citations (16)

An Investigation on Sensitivity of Ignition Delay and Activation Energy in Diesel Combustion

Journal of Engineering for Gas Turbines and Power (2015)

Umashankar Joshi Ziliang Zheng Amit Shrestha Naeim A. Henein Eric Sattler

The auto-ignition process plays a major role in the combustion, performance, fuel economy, and emission in diesel engines. The auto-ignition quality of different fuels has been rated by its cetane number (CN) determined in the cooperative fuel research engine, according to ASTM D613. More recently, the ignition quality tester (IQT), a constant volume vessel, has been used to determine the derived cetane number (DCN) to avoid the elaborate, time consuming, and costly engine tests, according to ASTM D6890. The ignition delay (ID) period in these two standard tests and many investigations has been considered to be the time period between start of injection (SOI) and start of combustion (SOC). The ID values determined in different investigations can vary due to differences in instrumentation and definitions. This paper examines the different definitions and the parameters that effect ID period. In addition, the activation energy dependence on the ID definition is investigated. Furthermore, results of an experimental investigation in a single-cylinder research diesel engine will be presented, while the charge density is kept constant during the ID period. The global activation energy is determined and its sensitivity to the charge temperature is examined.

Cetane number

Ignition timing

10.1115/1.4029777

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Citations (19)

Effect of Intake Pressure and Temperature on the Auto-Ignition of Fuels with Different Cetane Number and Volatility

SAE technical papers on CD-ROM/SAE technical paper series (2012)

Chandrasekharan Jayakumar Ziliang Zheng Umashankar Joshi Walter Bryzik Naeim A. Henein

Cetane number

10.4271/2012-01-1317

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Citations (19)

Experimental Validation and Combustion Modeling of a JP-8 Surrogate in a Single Cylinder Diesel Engine

SAE international journal of fuels and lubricants (2014)

Amit Shrestha Umashankar Joshi Ziliang Zheng Tamer Badawy Naeim A. Henein

This paper presents the results of an experimental investigation on a single cylinder engine to validate a two-component JP-8 surrogate. The two-component surrogate was chosen based on a previous investigation where the key properties, such as DCN, volatility, density, and lower heating value, of the surrogate were matched with those of the target JP-8.

The matching of the auto-ignition, combustion, and emission characteristics of the surrogate with JP-8 was investigated in an actual diesel engine environment. The engine tests for the validation of the surrogate were conducted at an engine speed of 1500 rpm, a load of 3 bar, and different injection timings. The results for the cylinder gas pressure, ignition delay period, rate of heat release, and the CO, HC, and NOx emissions showed a good match between the surrogate and the target JP-8. However, the engine-out particulate matter for the surrogate was lower than that for the JP-8 at all tested conditions. These findings are presented and discussed in the paper.

Additionally, a reduced surrogate fuel model was constructed and was implemented in three-dimensional CFD simulation for the predictions of the cylinder gas pressure, rate of heat release, and engine-out emissions of the tested surrogate. The CFD results were found to be in good agreement with the experimental data.

Crankcase

10.4271/2014-01-1376

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Citations (6)