Analysis of the ducted fuel injection concept for compression-ignition engines abstract.

2015 ◽  
Author(s):  
Christopher William Nilsen ◽  
Charles J. Mueller
Keyword(s):  
Fuel Injection ◽  
Compression Ignition ◽  
Compression Ignition Engines

Study of High Load Operation Limit Expansion for Gasoline Compression Ignition Engines

2006 ◽  
Vol 128 (2) ◽  
pp. 377-387 ◽  
Author(s):  
Koudai Yoshizawa ◽  
Atsushi Teraji ◽  
Hiroshi Miyakubo ◽  
Koichi Yamaguchi ◽  
Tomonori Urushihara
Keyword(s):  
Fuel Injection ◽  
Control Method ◽  
Combustion Process ◽  
High Load ◽  
Compression Ignition ◽  
Ignition Timing ◽  
Timing Control ◽  
Load Range ◽  
Compression Ignition Engines ◽  
Spark Plug

In this research, combustion characteristics of gasoline compression ignition engines have been analyzed numerically and experimentally with the aim of expanding the high load operation limit. The mechanism limiting high load operation under homogeneous charge compression ignition (HCCI) combustion was clarified. It was confirmed that retarding the combustion timing from top dead center (TDC) is an effective way to prevent knocking. However, with retarded combustion, combustion timing is substantially influenced by cycle-to-cycle variation of in-cylinder conditions. Therefore, an ignition timing control method is required to achieve stable retarded combustion. Using numerical analysis, it was found that ignition timing control could be achieved by creating a fuel-rich zone at the center of the cylinder. The fuel-rich zone works as an ignition source to ignite the surrounding fuel-lean zone. In this way, combustion consists of two separate auto-ignitions and is thus called two-step combustion. In the simulation, the high load operation limit was expanded using two-step combustion. An engine system identical to a direct-injection gasoline (DIG) engine was then used to validate two-step combustion experimentally. An air-fuel distribution was created by splitting fuel injection into first and second injections. The spark plug was used to ignite the first combustion. This combustion process might better be called spark-ignited compression ignition combustion (SI-CI combustion). Using the spark plug, stable two-step combustion was achieved, thereby validating a means of expanding the operation limit of gasoline compression ignition engines toward a higher load range.

Predicted Qualitative Effects of Alternate Liquid Fuels on Heavy-Duty Compression-Ignition Engines

2009 ◽  
Author(s):  
Gong Chen
Keyword(s):  
Fuel Injection ◽  
Cetane Number ◽  
Fuel Properties ◽  
Liquid Fuels ◽  
Compression Ignition ◽  
Heavy Duty ◽  
Compression Ignition Engine ◽  
End Effects ◽  
Compression Ignition Engines ◽  
The Impact

It is always desirable for a heavy-duty compression-ignition engine, such as a diesel engine, to possess a capability of using alternate liquid fuels without significant hardware modification to the engine baseline. Because fuel properties vary between various types of liquid fuels, it is important to understand the impact and effects of the fuel properties on engine operating and output parameters. This paper intends and attempts to achieve that understanding and to predict the qualitative effects by studying analytically and qualitatively how a heavy-duty compression-ignition engine would respond to the variation of fuel properties. The fuel properties considered in this paper mainly include the fuel density, compressibility, heating value, viscosity, cetane number, and distillation temperature range. The qualitative direct and end effects of the fuel properties on engine bulk fuel injection, in-cylinder combustion, and outputs are analyzed and predicted. Understanding these effects can be useful in analyzing and designing a compression-ignition engine for using alternate liquid fuels.

Soot reduction for cleaner Compression Ignition Engines through innovative bowl templates

2020 ◽  
pp. 146808742095132
Author(s):  
José V Pastor ◽  
Antonio García ◽  
Carlos Micó ◽  
Felipe Lewiski
Keyword(s):  
Fuel Injection ◽  
Oxidation Process ◽  
Soot Formation ◽  
Direct Injection ◽  
Soot Oxidation ◽  
Pollutant Emissions ◽  
Compression Ignition ◽  
Compression Ignition Engine ◽  
Compression Ignition Engines ◽  
Pollutant Reduction

Considering the need of pollutant emissions reduction and the high cost of the after-treatment systems, in-cylinder solutions for pollutant reduction are becoming more and more relevant. Among different proposals, new piston geometries are considered an attractive solution for reducing both soot and nitrogen oxides emissions in compression ignition engines. For this reason, this paper evaluates the soot formation and combustion characteristics of a novel piston geometry proposal, called stepped lip-wave, for light-duty engines. It is compared with other two well-known bowl geometries: re-entrant and stepped lip. The study was performed in an optical single-cylinder direct injection compression ignition engine. Two optical techniques (2 color pyrometry and OH* chemiluminescence) were applied for analyzing soot formation in each piston geometry. Test were performed at different engine loads, fuel injection characteristics and exhaust gas recirculation configuration. The re-entrant piston presents higher soot formation and a slower late oxidation process in comparison with the other two geometries. Stepped lip and stepped lip-wave present similar soot formation levels. However, stepped lip-wave showed a more efficient and faster soot oxidation process during the final combustion stages. Results confirm the potential of the stepped lip-wave concept to reduce soot emissions and achieve a cleaner energy production system.

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