Ignition Delay Model of Multiple Injections in CI Engines

2019 ◽  
Author(s):  
Youngbok Lee ◽  
Seungha Lee ◽  
Kyoungdoug Min
Keyword(s):  
Ignition Delay ◽  
Delay Model ◽  
Multiple Injections ◽  
Ci Engines

Enhanced Two-stage Ignition Delay Model Based on Molar Fraction of Fuel Components for SI Engine Simulation

2018 ◽  
Author(s):  
Kyoung Hyun Kwak ◽  
Dewey Jung ◽  
Hyunil Park ◽  
Jeonghwan Paeng ◽  
Kyumin Hwang
Keyword(s):  
Ignition Delay ◽  
Molar Fraction ◽  
Delay Model ◽  
Si Engine ◽  
Two Stage ◽  
Engine Simulation ◽  
Model Based ◽  
Fuel Components

Fuel-Sensitive Ignition Delay Models for a Local and Global Description of Direct Injection Internal Combustion Engines

2015 ◽  
Vol 137 (11) ◽  
Author(s):  
Kyoung Hyun Kwak ◽  
Claus Borgnakke ◽  
Dohoy Jung
Keyword(s):  
Ignition Delay ◽  
Alternative Fuels ◽  
Internal Combustion Engines ◽  
Cetane Number ◽  
Global Model ◽  
Local Model ◽  
Delay Model ◽  
Lower Accuracy ◽  
Delay Models ◽  
Single Calibration

Models for ignition delay are investigated and fuel-specific properties are included to predict the effects of different fuels on the ignition delay. These models follow the Arrhenius type expression for the ignition delay modified with the oxygen concentration and Cetane number to extend the range of validity. In this investigation, two fuel-sensitive spray ignition delay models are developed: a global model and a local model. The global model is based on the global combustion chamber charge properties including temperature, pressure, and oxygen/fuel content. The local model is developed to account for temporal and spatial variations in properties of separated spray zones such as local temperature, oxidizer, and fuel concentrations obtained by a quasi-dimensional multizone fuel spray model. These variations are integrated in time to predict the ignition delay. Often ignition delay models are recalibrated for a specific fuel but in this study, the global ignition delay model includes the Cetane number to capture ignition delay of various fuels. The local model uses Cetane number and local stoichiometric oxygen to fuel molar ratio. The model is therefore capable of predicting spray ignition delays for a set of fuels with a single calibration. Experimental dataset of spray ignition delay in a constant volume chamber is used for model development and calibration. The models show a good accuracy for the predicted ignition delay of four different fuels: JP8, DF2, n-heptane, and n-dodecane. The investigation revealed that the most accurate form of the models is from a calibration done for each individual fuel with only a slight decrease in accuracy when a single calibration is done for all fuels. The single calibration case is the more desirable outcome as it leads to general models that cover all the fuels. Of the two proposed models, the local model has a slightly better accuracy compared to the global model. Results for both models demonstrate the improvements that can be obtained for the ignition delay model when additional fuel-specific properties are included in the spray ignition model. Other alternative fuels like synthetic oxygenated fuels were included in the investigation. These fuels behave differently such that the Cetane number does not provide the same explanation for the trend in ignition delay. Though of lower accuracy, the new models do improve the predictive capability when compared with existing types of ignition delay models applied to this kind of fuels.

Effect of Fuel Reactivity on Ignitability and Combustion Phasing in a Heavy-Duty Engine Simulation for Mixing-Controlled and Partially Premixed Combustion

2017 ◽  
Vol 140 (4) ◽  
Author(s):  
Alexander K. Voice ◽  
Praveen Kumar ◽  
Yu Zhang
Keyword(s):  
Boundary Conditions ◽  
Ignition Delay ◽  
High Efficiency ◽  
Chemical Kinetic ◽  
Compression Ignition ◽  
Heavy Duty ◽  
Engine Model ◽  
Combustion Modes ◽  
Partially Premixed ◽  
Ci Engines

Light-end fuels have recently garnered interest as potential fuel for advanced compression ignition (CI) engines. This next generation of engines, which aim to combine the high efficiency of diesel engines with the relative simplicity of gasoline engines, may allow engine manufacturers to continue improving efficiency and reducing emissions without a large increase in engine and aftertreatment system complexity. In this work, a 1D heavy-duty engine model was validated with measured data and then used to generate boundary conditions for the detailed chemical kinetic simulation corresponding to various combustion modes and operating points. Using these boundary conditions, homogeneous simulations were conducted for 242 fuels with research octane number (RON) from 40 to 100 and sensitivity (S) from 0 to 12. Combustion phasing (CA50) was most dependent on RON and less dependent on S under all conditions. Both RON and S had a greater effect on combustion phasing under partially premixed compression ignition (PPCI) conditions (19.3 deg) than under mixing-controlled combustion (MCC) conditions (5.8 deg). The effect of RON and S were also greatest for the lowest reactivity (RON > 90) fuels and under low-load conditions. The results for CA50 reflect the relative ignition delay for the various fuels at the start-of-injection (SOI) temperature. At higher SOI temperatures (>950K), CA50 was found to be less dependent on fuel sensitivity due to the convergence of ignition delay behavior of different fuels in the high-temperature region. Combustion of light-end fuels in CI engines can be an important opportunity for regulators, consumers, and engine-makers alike. However, selection of the right fuel specifications will be critical in development of the combustion strategy. This work, therefore, provides a first look at quantifying the effect of light-end fuel chemistry on advanced CI engine combustion across the entire light-end fuel reactivity space and provides a comparison of the trends for different combustion modes.

Diesel Combustion and Control Using a Novel Ignition Delay Model

2018 ◽  
Author(s):  
Reza Rezaei ◽  
Benjamin Tilch ◽  
Thaddaeus Delebinski ◽  
Christoph Bertram
Keyword(s):  
Ignition Delay ◽  
Diesel Combustion ◽  
Delay Model ◽  
And Control

scholarly journals Problems with glow plug – a review

2021 ◽  
Author(s):  
Marek Wozniak ◽  
Gustavo Ozuna ◽  
Krzysztof Siczek
Keyword(s):  
Electric Vehicles ◽  
Ignition Delay ◽  
Delay Time ◽  
Ignition Delay Time ◽  
Engine Oil ◽  
Combustion Engines ◽  
Oil Viscosity ◽  
Glow Plug ◽  
Cold Starting ◽  
Ci Engines

Despite the development of hybrid and electric vehicles, a many-million population of cars with combustion engines, and particularly CI engines occurs on the roads. Also, many stationary CI engines are still utilized. Despite their improved technologies and characteristics the modern CI engines negatively affect an environment due to cold starting problems. Below 0 °C, engine starts are problematic due to the decreased battery performance and the spray characteristics, the increased ignition delay time, and the engine oil viscosity. Therefore, various glow plugs are applied to facilitate this process. Types, features, and applications of glow plugs in various engines have been discussed in the paper. One case of failure of glow plug has been presented in the article, including the cause of it.

Transient prediction capabilities of a novel physics-based ignition delay model in multi-pulsed direct injection diesel engines

2019 ◽  
Vol 21 (6) ◽  
pp. 948-965 ◽  
Author(s):  
J Jensen Samuel ◽  
A Ramesh
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Diesel Engines ◽  
Ignition Delay ◽  
Control Unit ◽  
Engine Control Unit ◽  
Boost Pressure ◽  
Engine Control ◽  
Multiple Injections ◽  
Modeling Methodology

This work is an extension of a novel physics-based ignition delay modeling methodology previously developed by the authors to predict physical and chemical ignition delays of multiple injections during steady operations in diesel engines. The modeling methodology is refined in this work to consider the influence of additional operating parameters such as volumetric efficiency, exhaust temperature and pressure on the ignition delay of multiple injections. Computational fluid dynamics predictions on two different engines indicated that the main spray encounters local temperatures about 60 K above average temperatures for about 1 mg of pilot. Hence, the modeling methodology was further refined to include this effect by considering the air mass trapped in pilot spray, computed based on the spray penetration and cone angle and tuned using results of the computational fluid dynamics studies. Comparisons of the ignition delay predictions with the stock boost temperature sensor and a specially incorporated, transient-capable fine wire thermocouple indicated that the measurements with stock sensor could be satisfactorily used for transients. Cycle-by-cycle changes in ignition delay could be predicted accurately when transients were imposed in boost pressure, rail pressure and main injection quantity in a turbocharged intercooled diesel engine controlled with an open engine control unit. Further validations were done even under a transient cycle when the engine was controlled by its stock engine control unit. The same tuning constants could be used for the prediction of the ignition delay under transients on another naturally aspirated engine. This indicates the suitability of the model for application in different engines. Finally, the model was incorporated within an open engine controller, and cycle-by-cycle prediction of ignition delays of the pilot and main injections were done in real time. It was possible to compute the ignition delays in less than 2 ms within engine control unit using the already available sensor inputs within an error band of ±60 µs.

Ignition delay prediction of multiple injections in diesel engines

Fuel ◽  
2014 ◽  
Vol 119 ◽  
pp. 170-190 ◽  
Author(s):  
Roberto Finesso ◽  
Ezio Spessa
Keyword(s):  
Diesel Engines ◽  
Ignition Delay ◽  
Multiple Injections ◽  
Delay Prediction
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