Comparison of Quantitative In-Cylinder Equivalence Ratio Measurements with CFD Predictions for a Light Duty Low Temperature Combustion Diesel Engine

2012 ◽  
Vol 5 (2) ◽  
pp. 162-184 ◽  
Author(s):  
Adam B. Dempsey ◽  
Bao-Lin Wang ◽  
Rolf D. Reitz ◽  
Benjamin Petersen ◽  
Dipankar Sahoo ◽  
...  
Keyword(s):  
Diesel Engine ◽  
Low Temperature ◽  
Equivalence Ratio ◽  
Low Temperature Combustion ◽  
Light Duty ◽  
Temperature Combustion

UHC and CO Emissions Sources From a Light-Duty Diesel Engine Undergoing Late-Injection Low-Temperature Combustion

2009 ◽  
Author(s):  
Isaac W. Ekoto ◽  
William F. Colban ◽  
Paul C. Miles ◽  
Ulf Aronsson ◽  
O¨ivind Andersson ◽  
...  
Keyword(s):  
High Temperature ◽  
Diesel Engine ◽  
Low Temperature ◽  
Injection Timing ◽  
Spatial Distributions ◽  
Low Temperature Combustion ◽  
Light Duty ◽  
Temperature Heat ◽  
Temperature Combustion ◽  
Homogeneous Reactor

Low load carbon monoxide (CO) and unburned hydrocarbon (UHC) emissions sources are examined in an optically accessible, light-duty diesel engine employing a late-injection, low-temperature combustion strategy. The study focus is to identify the cause of the rapid degradation in emissions and efficiency as injection timing is retarded. The in-cylinder progression of mixing and combustion processes is examined through ultraviolet planar laser-induced fluorescence (UV PLIF) imaging of hydrocarbon spatial distributions. Spectrally-resolved, deep-UV LIF measurements are also used to construct late-cycle spatial distributions of CO, C2, and polycyclic aromatic hydrocarbons within the clearance volume. Engine-out emissions measurements and numerical results from both detailed chemistry homogeneous reactor and multidimensional simulations complement the measurements. The measured spatial distributions show that while most fuel accumulates on the bowl-pip during high-temperature heat-release, much of it is transported into the squish-volume by the reverse squish flow. Homogeneous reactor simulations further show that expansion cooling quenches reactions, preventing the transition to high-temperature heat-release for mixtures with an equivalence ratio below 0.6. Lean squish-volume mixtures, coupled with wall heat losses, severely inhibit squish volume fuel oxidation. Further retarding injection timing exacerbates quenching, resulting in a two-fold increase in UHC emissions and a 33% increase in CO, primarily from the squish-volume.

Fuel Effects on Low Temperature Combustion in a Light-Duty Diesel Engine

2010 ◽  
Author(s):  
Alok Warey ◽  
Jean-Paul Hardy ◽  
Manuela Hennequin ◽  
Marek Tatur ◽  
Dean Tomazic ◽  
...  
Keyword(s):  
Diesel Engine ◽  
Low Temperature ◽  
Low Temperature Combustion ◽  
Light Duty ◽  
Temperature Combustion ◽  
Fuel Effects
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