Hydrocarbon Emissions from the Ignition-Delay Period in a Direct-Injection Diesel Engine

1984 ◽  
Author(s):  
Svend Henningsen
Keyword(s):  
Diesel Engine ◽  
Ignition Delay ◽  
Direct Injection ◽  
Delay Period ◽  
Hydrocarbon Emissions ◽  
Direct Injection Diesel Engine ◽  
Ignition Delay Period

scholarly journals MODELING OF IGNITION DELAY PERIOD IN DIESEL ENGINE

2019 ◽  
Vol 0 (1) ◽  
pp. 34-38
Author(s):  
А. П. Марченко ◽  
І. В. Парсаданов ◽  
А. В. Савченко
Keyword(s):  
Diesel Engine ◽  
Ignition Delay ◽  
Delay Period ◽  
Ignition Delay Period

Effects of Fuel Overpenetration and Overmixing During Ignition-Delay Period on Hydrocarbon Emissions From a Small Open-Chamber Diesel Engine

1988 ◽  
Vol 110 (3) ◽  
pp. 453-461 ◽  
Author(s):  
T.-W. Kuo ◽  
K.-J. Wu ◽  
S. Henningsen
Keyword(s):  
Diesel Engine ◽  
Ignition Delay ◽  
Fuel Injection ◽  
Swirling Flow ◽  
Delay Period ◽  
Injection Velocity ◽  
Spray Penetration ◽  
Hc Emissions ◽  
Start Of Combustion ◽  
Ignition Delay Period

A quasi-steady gas-jet model was applied to examine the spray trajectory in swirling flow during the ignition-delay period in an open-chamber diesel engine timed to start combustion at top dead center. Spray penetration, deflection, and the fractions of too-lean-mixed, burnable, and overpenetrated fuel at the start of combustion were calculated by employing the measured ignition delay and mean fuel-injection velocity. The calculated parameters were applied to correlate the measured exhaust hydrocarbon (HC) emissions. The engine parameters examined were bowl geometry, compression ratio, overall air-fuel ratio, and speed. Both the ignition delay and the relative spray-penetration parameter, defined as the ratio of the spray-penetration distances at the moments of start of combustion and wall impingement, gave good correlations for some of the engine parameters examined but could not explain all the measured trends. However, good correlation of the measured exhaust HC emissions was obtained by using the calculated too-lean-mixed and overpenetrated fuel fractions at the start of combustion. Correlation of the overpenetrated fuel with the measured HC indicated that approximately 2 percent of the fuel mass that overpenetrated before start of combustion emitted from the engine as unburned HC. This could account for 0 to 65 percent of the total HC emission from this engine. Additionally, it was found that the too-lean-mixed fuel could contribute 10 to 30 percent of the total HC emission, as found in a previous study on a somewhat similar engine. The remaining HC emission is caused by other sources such as bulk quenching.

Ignition Delay Period of Jojoba Diesel Engine Fuel

1997 ◽  
Author(s):  
M. S. Radwan ◽  
S. K. Dandoush ◽  
M. Y. E. Selim ◽  
A. M. A. Kader
Keyword(s):  
Diesel Engine ◽  
Ignition Delay ◽  
Delay Period ◽  
Engine Fuel ◽  
Ignition Delay Period

A physics-based model for real-time prediction of ignition delays of multi-pulse fuel injections in direct-injection diesel engines

2018 ◽  
Vol 21 (3) ◽  
pp. 540-558 ◽  
Author(s):  
Jensen Samuel J ◽  
Ramesh A
Keyword(s):  
Real Time ◽  
Diesel Engines ◽  
Ignition Delay ◽  
Direct Injection ◽  
Delay Period ◽  
Common Rail ◽  
Engine Control ◽  
Multiple Injections ◽  
Time Prediction ◽  
Ignition Delay Period

Real-time prediction of in-cylinder combustion parameters is very important for robust combustion control in any internal combustion engine. Very little information is available in the literature for modeling the ignition delay period of multiple injections that occur in modern direct-injection diesel engines. Knowledge of the ignition delay period in diesel engines with multiple injections is of primary interest due to its impact on pressure rise during subsequent combustion, combustion noise and pollutant formation. In this work, a physics-based ignition delay prediction methodology has been proposed by suitably simplifying an approach available in the literature. The time taken by the fuel-spray tip to reach the liquid length is considered as the physical delay period of any particular injection pulse. An equation has been developed for predicting the saturation temperature at this location based on the temperature and pressure at the start of injection. Thus, iterative procedures are avoided, which makes the methodology suitable for real-time engine control. The chemical delay was modeled by assuming a global reaction mechanism while using the Arrhenius-type equation. Experiments were conducted on a fully instrumented state-of-the-art common-rail diesel engine test facility for providing inputs to develop the methodology. The thermodynamic condition before the main injection was obtained by modeling the pilot combustion phase using the Wiebe function. Thus, the ignition delays of both pilot and main injections could be predicted based on rail pressure, injection timing, injection duration, manifold pressure and temperature which are normally used as inputs to the engine control unit. When the methodology was applied to predict the ignition delays in three different common-rail diesel engines, the ignition delays of pilot and main combustion phases could be predicted within an error band of ±25, ±50 and ±80 µs, respectively, without further tuning. This method can hence be used in real-time engine controllers and hardware-in-the-loop systems.

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