Cylinder-to-Cylinder Variations in a V6 Gasoline Direct Injection HCCI Engine

2009 ◽  
Vol 131 (4) ◽  
Author(s):  
Jacek Misztal ◽  
Hongming Xu ◽  
Miroslaw L. Wyszynski ◽  
Athanasios Tsolakis ◽  
Jun Qiao
Keyword(s):  
Direct Injection ◽  
Pressure Rise ◽  
Engine Performance ◽  
Gasoline Direct Injection ◽  
Experimental Investigations ◽  
Inlet Temperature ◽  
Split Injection ◽  
Hcci Engine ◽  
Combustion Technology ◽  
Cam Profile

Despite the fact that homogeneous charge compression ignition (HCCI) has been demonstrated as a combustion technology feasible for implementation with different fuels in various types of engines, cylinder-to-cylinder variations (CTCVs) in multicylinder HCCI engines remain one of the technical obstacles to overcome. A reduction in CTCV requires further developments in control technology. This study has been carried out with regard to the overall engine parameters, involving geometric differences between individual cylinders, coolant paths through the engine, combustion chamber deposits, and also the differences in the inlet temperature distributions between the cylinders. Experimental investigations on the Jaguar V6 HCCI research engine with negative valve overlapping and cam profile switching show that the differences in the rate of pressure rise between the cylinders can be larger than 1 bar/CA deg and that the load differences can be as high as 5–10%. It has been found that some individual cylinders will approach the misfiring limit far earlier than the others. The complex interaction between a number of parameters makes the control of the multicylinder engine a serious challenge. In order to avoid these differences, an active cylinder balancing strategy will be required. It has been observed that spark assistance and split injection strategy deliver the best control for the cylinder balance. However, spark assistance is restricted to low loads and low engine speeds, while split injection requires a considerable effort to optimize its possible settings. This paper defines the most important parameters influencing cylinder-to-cylinder variations in the HCCI engine and aims to put forward suggestions that can help to minimize the effect of cylinder-to-cylinder variations on the overall engine performance.

Economy and emission characteristics of the optimal dilution strategy in lean combustion based on GDI gasoline engine equipped with prechamber

2021 ◽  
Vol 13 (12) ◽  
pp. 168781402110381
Author(s):  
Li Wang ◽  
Zhaoming Huang ◽  
Wang Tao ◽  
Kai Shen ◽  
Weiguo Chen
Keyword(s):  
Fuel Economy ◽  
Gasoline Engine ◽  
Direct Injection ◽  
Engine Performance ◽  
Gasoline Direct Injection ◽  
Dilution Ratio ◽  
Lean Combustion ◽  
Excess Air ◽  
Combustion Phase ◽  
Hc Emissions

EGR and excess-air dilution have been investigated in a 1.5 L four cylinders gasoline direct injection (GDI) turbocharged engine equipped with prechamber. The influences of the two different dilution technologies on the engine performance are explored. The results show that at 2400 rpm and 12 bar, EGR dilution can adopt more aggressive ignition advanced angle to achieve optimal combustion phasing. However, excess-air dilution has greater fuel economy than that of EGR dilution owing to larger in-cylinder polytropic exponent. As for prechamber, when dilution ratio is greater than 37.1%, the combustion phase is advanced, resulting in fuel economy improving. Meanwhile, only when the dilution ratio is under 36.2%, the HC emissions of excess-air dilution are lower than the original engine. With the increase of dilution ratio, the CO emissions decrease continuously. The NOX emissions of both dilution technologies are 11% of those of the original engine. Excess-air dilution has better fuel economy and very low CO emissions. EGR dilution can effectively reduce NOX emissions, but increase HC emissions. Compared with spark plug ignition, the pre chamber ignition has lower HC, CO emissions, and higher NO emissions. At part load, the pre-chamber ignition reduces NOX emissions to 49 ppm.

Experimental Investigations of Performance and Emission Characteristics of Moringa Oil Methyl Ester and Its Diesel Blends in a Single Cylinder Direct Injection Diesel Engine

2009 ◽  
Author(s):  
Shyamsundar Rajaraman ◽  
G. K. Yashwanth ◽  
T. Rajan ◽  
R. Siva Kumaran ◽  
P. Raghu
Keyword(s):  
Diesel Engine ◽  
Alternative Fuels ◽  
Methyl Esters ◽  
Direct Injection ◽  
Engine Performance ◽  
Experimental Investigations ◽  
Emission Analysis ◽  
Performance And Emission ◽  
Direct Injection Diesel Engine ◽  
Moringa Oil

World at present is confronted with the twin crisis of fossil fuel depletion and environmental pollution. Rapid escalation in prices and hydrocarbon resources depletion has led us to look for alternative fuels, which can satisfy ever increasing demands of energy as well as protect the environment from noxious pollutants. In this direction an attempt has been made to study a biodiesel, namely Moringa Oil Methyl Esters [MOME]. All the experiments were carried out on a 4.4 kW naturally aspirated stationary direct injection diesel engine coupled with a dynamometer to determine the engine performance and emission analysis for MOME. It was observed that there was a reduction in HC, CO and PM emissions along with a substantial increase in NOx. MOME and its blends had slightly lower thermal efficiency than diesel oil.

scholarly journals Predicting Cycle-to-Cycle Variation With Concurrent Cycles in a Gasoline Direct Injected Engine With Large Eddy Simulations

2018 ◽  
Author(s):  
Daniel Probst ◽  
Sameera Wijeyakulasuriya ◽  
Eric Pomraning ◽  
Janardhan Kodavasal ◽  
Riccardo Scarcelli ◽  
...  
Keyword(s):  
Gasoline Engine ◽  
Direct Injection ◽  
Engine Performance ◽  
Turnaround Time ◽  
Operating Conditions ◽  
Gasoline Direct Injection ◽  
Cycle Variation ◽  
Spark Timing ◽  
Large Eddy ◽  
Operating Points

High cycle-to-cycle variation (CCV) is detrimental to engine performance, as it leads to poor combustion and high noise and vibration. In this work, CCV in a gasoline engine is studied using large eddy simulation (LES). The engine chosen as the basis of this work is a single-cylinder gasoline direct injection (GDI) research engine. Two stoichiometric part-load engine operating points (6 BMEP, 2000 RPM) were evaluated: a non-dilute (0% EGR) case and a dilute (18% EGR) case. The experimental data for both operating conditions had 500 cycles. The measured CCV in IMEP was 1.40% for the non-dilute case and 7.78% for the dilute case. To estimate CCV from simulation, perturbed concurrent cycles of engine simulations were compared to consecutively obtained engine cycles. The motivation behind this is that running consecutive cycles to estimate CCV is quite time-consuming. For example, running 100 consecutive cycles requires 2–3 months (on a typical cluster), however, by running concurrently one can potentially run all 100 cycles at the same time and reduce the overall turnaround time for 100 cycles to the time taken for a single cycle (2 days). The goal of this paper is to statistically determine if concurrent cycles, with a perturbation applied to each individual cycle at the start, can be representative of consecutively obtained cycles and accurately estimate CCV. 100 cycles were run for each case to obtain statistically valid results. The concurrent cycles began at different timings before the combustion event, with the motivation to identify the closest time before spark to minimize the run time. Only a single combustion cycle was run for each concurrent case. The calculated standard deviation of peak pressure and coefficient of variance (COV) of indicated mean effective pressure (IMEP) were compared between the consecutive and concurrent methods to quantify CCV. It was found that the concurrent method could be used to predict CCV with either a velocity or numerical perturbation. A large and small velocity perturbation were compared and both produced correct predictions, implying that the type of perturbation is not important to yield a valid realization. Starting the simulation too close to the combustion event, at intake valve close (IVC) or at spark timing, under-predicted the CCV. When concurrent simulations were initiated during or before the intake even, at start of injection (SOI) or earlier, distinct and valid realizations were obtained to accurately predict CCV for both operating points. By simulating CCV with concurrent cycles, the required wall clock time can be reduced from 2–3 months to 1–2 days. Additionally, the required core-hours can be reduced up to 41%, since only a portion of each cycle needs to be simulated.

Effect of Fuel Injection Pressure and Engine Speed on Performance, Emissions, Combustion, and Particulate Investigations of Gasohols Fuelled Gasoline Direct Injection Engine

2019 ◽  
Vol 142 (4) ◽  
Author(s):  
Nikhil Sharma ◽  
Avinash Kumar Agarwal
Keyword(s):  
Internal Combustion Engines ◽  
Fuel Injection ◽  
Driving Forces ◽  
Direct Injection ◽  
Engine Performance ◽  
Injection Pressure ◽  
Operating Conditions ◽  
Gasoline Direct Injection ◽  
Primary Alcohols ◽  
Renewable Fuel

Abstract Fuel availability, global warming, and energy security are the three main driving forces, which determine suitability and long-term implementation potential of a renewable fuel for internal combustion engines for a variety of applications. Comprehensive engine experiments were conducted in a single-cylinder gasoline direct injection (GDI) engine prototype having a compression ratio of 10.5, for gaining insights into application of mixtures of gasoline and primary alcohols. Performance, emissions, combustion, and particulate characteristics were determined at different engine speeds (1500, 2000, 2500, 3000 rpm), different fuel injection pressures (FIP: 40, 80, 120, 160 bars) and different test fuel blends namely 15% (v/v) butanol, ethanol, and methanol blended with gasoline, respectively (Bu15, E15, and M15) and baseline gasoline at a fixed (optimum) spark timing of 24 deg before top dead center (bTDC). For a majority of operating conditions, gasohols exhibited superior characteristics except minor engine performance penalty. Gasohols therefore emerged as serious candidate as a transitional renewable fuel for utilization in the existing GDI engines, without requirement of any major hardware changes.

Experimental investigations on combustion of jatropha methyl ester in a turbocharged direct-injection diesel engine

2008 ◽  
Vol 222 (10) ◽  
pp. 1865-1877 ◽  
Author(s):  
K Anand ◽  
R P Sharma ◽  
P S Mehta
Keyword(s):  
Diesel Engine ◽  
Methyl Ester ◽  
Diesel Fuel ◽  
Fuel Injection ◽  
Peak Pressure ◽  
Direct Injection ◽  
Pressure Rise ◽  
Experimental Investigations ◽  
Injection Timing ◽  
Gas Temperature

Suitability of vegetable oil as an alternative to diesel fuel in compression ignition engines has become attractive, and research in this area has gained momentum because of concerns on energy security, high oil prices, and increased emphasis on clean environment. The experimental work reported here has been carried out on a turbocharged direct-injection multicylinder truck diesel engine using diesel fuel and jatropha methyl ester (JME)-diesel blends. The results of the experimental investigation indicate that an increase in JME quantity in the blend slightly advances the dynamic fuel injection timing and lowers the ignition delay compared with the diesel fuel. A maximum rise in peak pressure limited to 6.5 per cent is observed for fuel blends up to 40 per cent JME for part-load (up to about 50 per cent load) operations. However, for a higher-JME blend, the peak pressures decrease at higher loads remained within 4.5 per cent. With increasing proportion of JME in the blend, the peak pressure occurrence slightly advances and the maximum rate of pressure rise, combustion duration, and exhaust gas temperature decrease by 9 per cent, 15 per cent and 17 per cent respectively. Although the changes in brake thermal efficiencies for 20 per cent and 40 per cent JME blends compared with diesel fuel remain insignificant, the 60 per cent JME blend showed about 2.7 per cent improvement in the brake thermal efficiency. In general, it is observed that the overall performance and combustion characteristics of the engine do not alter significantly for 20 per cent and 40 per cent JME blends but show an improvement over diesel performance when fuelled with 60 per cent JME blend.

Research on Steady and Transient Performance of an HCCI Engine with Gasoline Direct Injection

2008 ◽  
Author(s):  
Zhi Wang ◽  
Jian-Xin Wang ◽  
Guo-hong Tian ◽  
Shi-Jin Shuai ◽  
Zhifu Zhang ◽  
...  
Keyword(s):  
Direct Injection ◽  
Gasoline Direct Injection ◽  
Transient Performance ◽  
Hcci Engine

Numerical Simulations of Hollow Cone Injection and Gasoline Compression Ignition Combustion With Naphtha Fuels

2015 ◽  
Author(s):  
Jihad A. Badra ◽  
Jaeheon Sim ◽  
Ahmed Elwardany ◽  
Mohammed Jaasim ◽  
Yoann Viollet ◽  
...  
Keyword(s):  
Experimental Data ◽  
Direct Injection ◽  
Gasoline Direct Injection ◽  
Experimental Investigations ◽  
Attractive Alternative ◽  
Spray Parameters ◽  
Compression Ignition ◽  
Hollow Cone ◽  
Modeling Framework ◽  
Primary Reference

Gasoline compression ignition (GCI), also known as partially premixed compression ignition (PPCI) and gasoline direct injection compression ignition (GDICI), engines have been considered an attractive alternative to traditional spark ignition engines. Lean burn combustion with the direct injection of fuel eliminates throttle losses for higher thermodynamic efficiencies, and the precise control of the mixture compositions allows better emission performance such as NOx and particulate matter (PM). Recently, low octane gasoline fuel has been identified as a viable option for the GCI engine applications due to its longer ignition delay characteristics compared to diesel and lighter evaporation compared to gasoline fuel [1]. The feasibility of such a concept has been demonstrated by experimental investigations at Saudi Aramco [1, 2]. The present study aims to develop predictive capabilities for low octane gasoline fuel compression ignition engines with accurate characterization of the spray dynamics and combustion processes. Full three-dimensional simulations were conducted using CONVERGE as a basic modeling framework, using Reynolds-averaged Navier-Stokes (RANS) turbulent mixing models. An outwardly opening hollow-cone spray injector was characterized and validated against existing and new experimental data. An emphasis was made on the spray penetration characteristics. Various spray breakup and collision models have been tested and compared with the experimental data. An optimum combination has been identified and applied in the combusting GCI simulations. Linear instability sheet atomization (LISA) breakup model and modified Kelvin-Helmholtz and Rayleigh-Taylor (KH-RT) break models proved to work the best for the investigated injector. Comparisons between various existing spray models and a parametric study have been carried out to study the effects of various spray parameters. The fuel effects have been tested by using three different primary reference fuel (PRF) and toluene primary reference fuel (TPRF) surrogates. The effects of fuel temperature and chemical kinetic mechanisms have also been studied. The heating and evaporative characteristics of the low octane gasoline fuel and its PRF and TPRF surrogates were examined.

Investigation of injector coking effects on spray characteristic and engine performance in gasoline direct injection engines

2018 ◽  
Vol 220 ◽  
pp. 375-394 ◽  
Author(s):  
Tawfik Badawy ◽  
Mohammadreza Anbari Attar ◽  
Peter Hutchins ◽  
Hongming Xu ◽  
Jens Krueger Venus ◽  
...  
Keyword(s):  
Direct Injection ◽  
Engine Performance ◽  
Gasoline Direct Injection ◽  
Direct Injection Engines ◽  
Spray Characteristic

Effect of Spark Timing on Performance of a Hydrogen Gasoline Engine

2015 ◽  
Vol 713-715 ◽  
pp. 239-242 ◽  
Author(s):  
Wei Bo Shi ◽  
Xiu Min Yu ◽  
Ping Sun
Keyword(s):  
Gasoline Engine ◽  
Direct Injection ◽  
Engine Performance ◽  
Spark Ignition Engine ◽  
Gasoline Direct Injection ◽  
Hydrogen Energy ◽  
Energy Fraction ◽  
Direct Injection Engine ◽  
Excess Air ◽  
Spark Timing

Hydrogen-gasoline blends is an effective way to improving the performance of spark ignition engine at stoichiometric and lean conditions. Spark timing is one of the important parameters affect the engine performance. This paper investigated the effect of spark timing on performance of a hydrogen-gasoline engine. A four cylinder, gasoline direct injection engine was modified to be a gasoline port injection, hydrogen direct injection engine. The hydrogen energy fraction was set as 0% and 30%. For a specified hydrogen addition, the engine was operated at four excess air ratios of 0.8, 1.0, 1.2 and 1.5. Under the specified excess air ratio condition, the spark timing was varied from 4 to 19°CA before top dead center (BTDC) with an interval of 3°CA. The test result showed that the indicated mean effective pressure (IMEP) climb up and then decline with the increase of spark advance. For hydrogen-gasoline engine, the optimum spark timing for the max IMEP was retarded at a specified excess air ratio. The max thermal efficiency appeared at the optimum spark timing.

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