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

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.

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

scholarly journals Model-Based Pre-Ignition Diagnostics in a Race Car Application

Energies ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 2277 ◽  
Author(s):  
Vittorio Ravaglioli ◽  
Carlo Bussi
Keyword(s):  
Ignition Delay ◽  
Hot Spots ◽  
Hot Spot ◽  
Electronic Control Unit ◽  
Control Unit ◽  
Cylinder Pressure ◽  
Real Time Processing ◽  
Spark Plug ◽  
Pressure Trace ◽  
And Control

Since 2014, Formula 1 engines have been turbocharged spark-ignited engines. In this scenario, the maximum engine power available in full-load conditions can be achieved only by optimizing combustion phasing within the cycle, i.e., by advancing the center of combustion until the limit established by the occurrence of abnormal combustion. High in-cylinder pressure peaks and the possible occurrence of knocking combustion significantly increase the heat transfer to the walls and might generate hot spots inside the combustion chamber. This work presents a methodology suitable to properly diagnose and control the occurrence of pre-ignition events that emanate from hot spots. The methodology is based on a control-oriented model of the ignition delay, which is compared to the actual ignition delay calculated from the real-time processing of the in-cylinder pressure trace. When the measured ignition delay becomes significantly smaller than that modeled, it means that ignition has been activated by a hot spot instead of the spark plug. In this case, the presented approach, implemented in the electronic control unit (ECU) that manages the whole hybrid power unit, detects a pre-ignition event and corrects the injection pattern to avoid the occurrence of further abnormal combustion.

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