CFD Study on Effects of Thermal and Residual Gas Inhomogeneous Distribution on Auto-ignition of Gasoline HCCI Combustion

2010 ◽  
Author(s):  
Nan Li ◽  
Hui Xie ◽  
Mengqin Shen ◽  
Hua Zhao
Keyword(s):  
Inhomogeneous Distribution ◽  
Hcci Combustion ◽  
Auto Ignition ◽  
Residual Gas

Pressure Sensitivity of HCCI Auto-Ignition Temperature for Oxygenated Reference Fuels

2012 ◽  
Author(s):  
Ida Truedsson ◽  
Martin Tuner ◽  
Bengt Johansson ◽  
William Cannella
Keyword(s):  
Compression Ratio ◽  
Ignition Temperature ◽  
Equivalence Ratio ◽  
Engine Speed ◽  
Pressure Sensitivity ◽  
Hcci Combustion ◽  
Air Temperatures ◽  
Auto Ignition ◽  
Temperature Heat ◽  
Pressure Trace

The current research focuses on creating an HCCI fuel index suitable for comparing different fuels for HCCI operation. One way to characterize a fuel is to use the Auto-Ignition Temperature (AIT). The AIT can be extracted from the pressure trace. Another potentially interesting parameter is the amount of Low Temperature Heat Release (LTHR) that is closely connected to the ignition properties of the fuel. The purpose of this study was to map the AIT and amount of LTHR of different oxygenated reference fuels in HCCI combustion at different cylinder pressures. Blends of n-heptane, iso-octane and ethanol were tested in a CFR engine with variable compression ratio. Five different inlet air temperatures ranging from 50°C to 150°C were used to achieve different cylinder pressures and the compression ratio was changed accordingly to keep a constant combustion phasing, CA50, of 3±1° after TDC. The experiments were carried out in lean operation with a constant equivalence ratio of 0.33 and with a constant engine speed of 600 rpm. The amount of ethanol needed to suppress LTHR from different PRFs was evaluated. The AIT and the amount of LTHR for different combinations of n-heptane, iso-octane and ethanol were charted.

Computational Analysis of an Early Direct Injected HCCI Engine with Turbocharger Using Bio Ethanol and Diesel Blends

2015 ◽  
Vol 812 ◽  
pp. 70-78
Author(s):  
S. Natarajan ◽  
A.U. Meeanakshi Sundareswaran ◽  
S. Arun Kumar ◽  
N.V. Mahalakshmi
Keyword(s):  
Chemical Kinetics ◽  
Computational Analysis ◽  
Reaction Path ◽  
Chemical Species ◽  
Operating Conditions ◽  
Injection Time ◽  
Engine Operation ◽  
Hcci Engine ◽  
Hcci Combustion ◽  
Auto Ignition

In this paper the work deals with the computational analysis of early direct injected HCCI engine with turbocharger using the CHEMKIN-PRO software. The computational analysis was carried out in the base of auto ignition chemistry by means of reduced chemical kinetics. For this study the neat diesel and Bio ethanol diesel blend (E20) were used as fuel. The inlet pressure was increased to 1.2 bar to simulate the turbocharged engine operation. The injection time was advanced to 18° before top dead centre (BTDC) i.e., 5° BTDC than normal injection time of 23° BTDC. The equivalence ratio was kept at 0.6 (ɸ=0.6) and the combustion, emission characteristics and chemical kinetics of the combustion reaction were studied. Since pressure and temperature profiles plays a very important role in reaction path at certain operating conditions, an attempt had been made here to present a complete reaction path investigation on the formation/destruction of chemical species at peak temperature and pressure conditions. The result showed that main draw backs of HCCI combustion like higher levels of unburned hydrocarbon emissions and carbon monoxide emissions are reduced in the turbocharged operation of the HCCI engine when compared to normal HCCI engine operation without turbocharger.

Effect of Premixed Diesel Fuel on Partial HCCI Combustion Characteristics

2014 ◽  
Vol 663 ◽  
pp. 26-33
Author(s):  
Y.H. Teoh ◽  
H.H. Masjuki ◽  
M.A. Kalam ◽  
Muhammad Afifi Amalina ◽  
H.G. How
Keyword(s):  
Diesel Fuel ◽  
Engine Speed ◽  
Direct Injection ◽  
Compression Ignition ◽  
Cylinder Pressure ◽  
Compression Ignition Engine ◽  
Hcci Combustion ◽  
Light Duty ◽  
Auto Ignition ◽  
Ignition Characteristics

This study investigated the effects of premixed diesel fuel on the auto-ignition characteristics in a light duty compression ignition engine. A partial homogeneous chargecompression ignition (HCCI) engine was modified from a single cylinder, four-stroke, direct injection compression ignition engine. The partial HCCI is achieved by injecting diesel fuel into the intake port of the engine, while maintaining diesel fuel injected in cylinder for combustion triggering. The auto-ignition of diesel fuel has been studied at various premixed ratios from 0 to 0.60, under engine speed of 1600 rpm and 20Nm load. The results for performance, emissions and combustion were compared with those achieved without premixed fuel. From the heat release rate (HRR) profile which was calculated from in-cylinder pressure, it is clearly observed that two-stage and three-stage ignition were occurred in some of the cases. Besides, the increases of premixed ratio to some extent have significantly reduced in NO emission.

Effect of water blending on bioethanol HCCI combustion with forced induction and residual gas trapping

Energy ◽  
2007 ◽  
Vol 32 (12) ◽  
pp. 2396-2400 ◽  
Author(s):  
A. Megaritis ◽  
D. Yap ◽  
M.L. Wyszynski
Keyword(s):  
Effect Of Water ◽  
Hcci Combustion ◽  
Gas Trapping ◽  
Residual Gas
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