Fuel Octane Effects in the Partially Premixed Combustion Regime in Compression Ignition Engines

2009 ◽  
Author(s):  
Leif Hildingsson ◽  
Gautam Kalghatgi ◽  
Nigel Tait ◽  
Bengt Johansson ◽  
Andrew Harrison
Keyword(s):  
Combustion Regime ◽  
Premixed Combustion ◽  
Compression Ignition ◽  
Compression Ignition Engines ◽  
Partially Premixed Combustion ◽  
Partially Premixed

scholarly journals Combustion stratification study of partially premixed combustion using Fourier transform analysis of OH* chemiluminescence images

2017 ◽  
Vol 19 (10) ◽  
pp. 1024-1035 ◽  
Author(s):  
Mohammad Izadi Najafabadi ◽  
Bart Somers ◽  
Bengt Johansson ◽  
Nico Dam
Keyword(s):  
Heat Release ◽  
High Speed ◽  
Spatial Information ◽  
Fourier Transforms ◽  
Combustion Regime ◽  
Premixed Combustion ◽  
Two Dimensional ◽  
Spatial Frequencies ◽  
Partially Premixed Combustion ◽  
Partially Premixed

A relatively high level of stratification (qualitatively: lack of homogeneity) is one of the main advantages of partially premixed combustion over the homogeneous charge compression ignition concept. Stratification can smooth the heat release rate and improve the controllability of combustion. In order to compare stratification levels of different partially premixed combustion strategies or other combustion concepts, an objective and meaningful definition of “stratification level” is required. Such a definition is currently lacking; qualitative/quantitative definitions in the literature cannot properly distinguish various levels of stratification. The main purpose of this study is to objectively define combustion stratification (not to be confused with fuel stratification) based on high-speed OH* chemiluminescence imaging, which is assumed to provide spatial information regarding heat release. Stratification essentially being equivalent to spatial structure, we base our definition on two-dimensional Fourier transforms of photographs of OH* chemiluminescence. A light-duty optical diesel engine has been used to perform the OH* bandpass imaging on. Four experimental points are evaluated, with injection timings in the homogeneous regime as well as in the stratified partially premixed combustion regime. Two-dimensional Fourier transforms translate these chemiluminescence images into a range of spatial frequencies. The frequency information is used to define combustion stratification, using a novel normalization procedure. The results indicate that this new definition, based on Fourier analysis of OH* bandpass images, overcomes the drawbacks of previous definitions used in the literature and is a promising method to compare the level of combustion stratification between different experiments.

Compression Ignition of Low Octane Gasoline under Partially Premixed Combustion Mode

2018 ◽  
Author(s):  
Yanzhao An ◽  
Mohammed Jaasim Mubarak Ali ◽  
R Vallinayagam ◽  
Abdullah AlRamadan ◽  
Jaeheon Sim ◽  
...  
Keyword(s):  
Premixed Combustion ◽  
Compression Ignition ◽  
Combustion Mode ◽  
Partially Premixed Combustion ◽  
Partially Premixed

Fuel Stratification and Partially Premixed Combustion With Neat n-Butanol in a Compression Ignition Engine

2018 ◽  
Vol 140 (12) ◽  
Author(s):  
Shouvik Dev ◽  
Tongyang Gao ◽  
Xiao Yu ◽  
Mark Ives ◽  
Ming Zheng
Keyword(s):  
Fuel Injection ◽  
Direct Injection ◽  
Premixed Combustion ◽  
Injection Timing ◽  
Compression Ignition ◽  
Compression Ignition Engine ◽  
Fuel Stratification ◽  
Partially Premixed Combustion ◽  
Partially Premixed ◽  
Ci Engines

Homogeneous charge compression ignition (HCCI) has been considered as an ideal combustion mode for compression ignition (CI) engines due to its superb thermal efficiency and low emissions of nitrogen oxides (NOx) and particulate matter. However, a challenge that limits practical applications of HCCI is the lack of control over the combustion rate. Fuel stratification and partially premixed combustion (PPC) have considerably improved the control over the heat release profile with modulations of the ratio between premixed fuel and directly injected fuel, as well as injection timing for ignition initiation. It leverages the advantages of both conventional direct injection compression ignition and HCCI. In this study, neat n-butanol is employed to generate the fuel stratification and PPC in a single cylinder CI engine. A fuel such as n-butanol can provide additional benefits of even lower emissions and can potentially lead to a reduced carbon footprint and improved energy security if produced appropriately from biomass sources. Intake port fuel injection (PFI) of neat n-butanol is used for the delivery of the premixed fuel, while the direct injection (DI) of neat n-butanol is applied to generate the fuel stratification. Effects of PFI-DI fuel ratio, DI timing, and intake pressure on the combustion are studied in detail. Different conditions are identified at which clean and efficient combustion can be achieved at a baseline load of 6 bar IMEP. An extended load of 14 bar IMEP is demonstrated using stratified combustion with combustion phasing control.

Sources of UHC Emissions from a Light-Duty Diesel Engine Operating in a Partially Premixed Combustion Regime

2009 ◽  
Vol 2 (1) ◽  
pp. 1265-1289 ◽  
Author(s):  
Isaac W. Ekoto ◽  
Will F. Colban ◽  
Paul C. Miles ◽  
Sungwook Park ◽  
David E. Foster ◽  
...  
Keyword(s):  
Diesel Engine ◽  
Combustion Regime ◽  
Premixed Combustion ◽  
Light Duty ◽  
Partially Premixed Combustion ◽  
Partially Premixed

scholarly journals Study of the Combustion Process of a Homogeneous Charge Compression Ignition (HCCI) Engine and a Partially Premixed Combustion (PPC) Mode of a Compression Ignition Engine Using Natural Gas as an Alternative Fuel

2021 ◽  
Vol 84 (2) ◽  
pp. 98-115
Author(s):  
Saliha Mohammed Belkebir ◽  
Benyoucef Khelidj ◽  
Miloud Tahar-Abbes
Keyword(s):  
Homogeneous Charge Compression Ignition ◽  
Combustion Process ◽  
Flow Simulation ◽  
Premixed Combustion ◽  
Compression Ignition ◽  
Compression Ignition Engine ◽  
Hcci Engine ◽  
Partially Premixed Combustion ◽  
Partially Premixed ◽  
Homogeneous Charge

In order to investigate a viable approach to achieving high efficiencies and low nitrogen oxide (NOX) emissions, this paper presents the application of a homogeneous charge compression ignition (HCCI) engine and the partially premixed combustion (PPC) mode applied to a heavy diesel engine. The effect of carbon dioxide (CO2) fraction on combustion parameters was analyzed and discussed in detail. For this purpose, on the one hand, ANSYS CHEMKIN-Pro software was used to perform simulations of a closed homogeneous reactor under conditions relevant to HCCI engines, and on the other hand, ANSYS-Fluent software was used by adding a CO2 fraction varying from 20% to 58% to methane fuel to study 2D flow simulation by applying a PPC combustion mode to predict the distribution of various output parameters such as in-cylinder temperature, in-cylinder pressure and emissions. In comparison with the two presented models, it was found that the HCCI engine showed a lower NOX level than the PPC mode and this was due to the lower in-cylinder temperature in the HCCI engine.

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