3D CFD Modeling and Validation of Ion Current Sensor in a Gen-Set Diesel Engine Using Chemical Kinetic Mechanism

2016 ◽  
Author(s):  
Tamer Badawy ◽  
Naeim Henein
Keyword(s):  
Diesel Engine ◽  
Combustion Chamber ◽  
Diesel Engines ◽  
Combustion Process ◽  
Ion Current ◽  
Cfd Modeling ◽  
Ionization Mechanism ◽  
Current Signal ◽  
Current Sensing ◽  
Cycle Simulation

The control of the combustion process is becoming a necessity for diesel engines in order to meet the upcoming stringent emission regulations. Ion current sensing technology has the potential to provide real-time feedback of the combustion process while using a fairly inexpensive sensor. 3D computational fluid dynamics (CFD) cycle simulation is becoming more complementary in understanding the complex combustion process in diesel engines. In this paper, a CFD study is focused on investigating the characteristics of the ion current signal produced during the combustion process of a Gen-set turbocharged diesel engine. Multiple virtual ion sensing probes are defined in different locations inside the combustion chamber to understand the influence of sensor location on signal characteristics. The n-heptane reaction mechanism and NO mechanism, combined with an ionization mechanism developed at WSU with 11 species, are used in the model to predict the chemical kinetics of combustion and the mole fraction of ionized species produced during combustion. Since the charge in diesel engines is heterogeneous and due to the sensing nature of the ion sensor, this paper explores the effect of sensor sensing diameter and its protrusion depth inside the combustion chamber on the ion current signal development. The simulation is validated by comparing in-cylinder pressure traces, the rate of heat release, and the ion current signal. Further, the model results are validated under different engine loads and injection pressures. This study utilizes the ionization mechanism to give further understanding of the complex formation of ionization species and their amplitudes, particularly at local sensing locations. This can be very vital to identify the potentials of using the ion current sensing and highlight its viability in feedback closed loop combustion control.

Modeling of Ion Current Signal in Diesel Combustion

2013 ◽  
Author(s):  
Fadi Estefanous
Keyword(s):  
Internal Combustion Engines ◽  
Combustion Process ◽  
Operating Conditions ◽  
Ion Current ◽  
Ionization Mechanism ◽  
Diesel Combustion ◽  
Current Signal ◽  
Three Dimensional Model ◽  
Cycle Simulation ◽  
Soot Precursors

Ionization in internal combustion engines produces a signal indicative of in-cylinder conditions that can be used for the feedback electronic control of the engine, to meet production goals in performance, fuel economy and emissions. Most of the research has been conducted on carbureted and port injection spark ignition engines where the ionization mechanisms are well defined. A limited number of investigations have been conducted on ionization in diesel engines because of its complex combustion process. In this study, a detailed ionization mechanism is developed and introduced in a 3-D diesel cycle simulation computational fluid dynamics (CFD) code to determine the contribution of different species in the ionization process at different engine operating conditions. The CFD code is coupled with DARS-CFD, another module used to allow chemical kinetics calculations. The three-dimensional model accounts for the heterogeneity of the charge and the resulting variations in the combustion products. Furthermore, the model shows the effects of varying fuel injection pressure and engine load on the ion current signal characteristics. Ion current traces obtained experimentally from a heavy duty diesel engine were compared to the 3-D model results. The results of the simulation indicate that some heavy hydrocarbons, soot precursors play a major role, in addition to the role of NOx in ionization in diesel combustion.

Analysis and Research of the Combustion Process of YN4100QB Diesel Engine

2013 ◽  
Vol 744 ◽  
pp. 35-39
Author(s):  
Lei Ming Shi ◽  
Guang Hui Jia ◽  
Zhi Fei Zhang ◽  
Zhong Ming Xu
Keyword(s):  
Diesel Engine ◽  
Internal Combustion Engine ◽  
Combustion Chamber ◽  
Optimization Design ◽  
Combustion Engine ◽  
Geometric Model ◽  
Combustion Process ◽  
Internal Combustion ◽  
Engine Combustion ◽  
Exhaust Noise

In order to obtain the foundation to the research on the Diesel Engine YN4100QB combustion process, exhaust, the optimal design of combustion chamber and the useful information for the design of exhaust muffler, the geometric model and mesh model of a type internal combustion engine are constructed by using FIRE software to analyze the working process of internal combustion engine. Exhaust noise is the main component of automobile noise in the study of controlling vehicle noise. It is primary to design a type of muffler which is good for agricultural automobile engine matching and noise reduction effect. The present car mufflers are all development means. So it is bound to cause the long cycle of product development and waste of resources. Even sometimes not only can it not reach the purpose of reducing the noise but also it leads to reduce the engine dynamic. The strength of the exhaust noise is closely related to engine combustion temperature and pressure. The calculation and initial parameters are applied to the software based on the combustion model and theory. According to the specific operation process of internal combustion engine. Five kinds of common operation condition was compiled. It is obtained for the detailed distribution parameters of combusted gas temperature pressure . It is also got for flow velocity of the fields in cylinder and given for the relation of the parameters and crankshaft angle for the further research. At the same time NOx emissions situation are got. The numerical results show that not only does it provide the 3D distribution data in different crank shaft angle inside the cylinder in the simulation of combustion process, but also it provides a basis for the engine combustion ,emission research, the optimization design of the combustion chamber and the useful information for the designs of muffler.

Experimental and theoretical study of particulate re-entrainment from the combustion chamber walls of a diesel engine

1997 ◽  
Vol 211 (1) ◽  
pp. 49-57 ◽  
Author(s):  
M Abu-Qudais ◽  
D. B. Kittelson
Keyword(s):  
Particulate Matter ◽  
Diesel Engine ◽  
Combustion Chamber ◽  
Mass Concentration ◽  
High Surface ◽  
Combustion Process ◽  
Surface Shear ◽  
Time Resolved ◽  
Soot Deposition ◽  
Engine Cycle

The purpose of this research was to investigate the influence of the in-cylinder surfaces on the net emission of the particulate matter in the exhaust of a single cylinder, diesel engine. In order to obtain this information, time-resolved sampling was done to characterize the particulate matter emitted in the engine exhaust. A rotating probe sampled the free exhaust plume once each engine cycle. The rotation of the probe was synchronized with the engine cycle in such a way that the samples could be taken at any predetermined crank angle degree window. The sampling probe was designed for isokinetic sampling in order to obtain reliable results. To characterize the exhaust particulate in real time, a filter for mass concentration measurements was used. The results showed about 45 per cent higher mass concentrations as well as particles of larger diameter emitted during blowdown than late in the displacement phase of the exhaust stroke. This suggests that high in-cylinder shear rates and velocities which are associated with the blowdown process, cause the deposited soot to be re-entrained from the surfaces of the combustion chamber, where re-entrainment is favoured by conditions of high surface shear. A mathematical model to predict the amount of soot re-entrained from the cylinder walls is presented. This model is based on information presented in the literature along with the results of the time-resolved measurements of mass concentration. This model supported the hypothesis of soot deposition during the combustion process, with subsequent re-entrainment during the blowdown process of the exhaust stroke.

Experimental Study on the Combustion Process and Performance of Diesel Engines Fueled by Emulsion Diesel With Novel Organic Additives

2013 ◽  
Author(s):  
Wenming Yang ◽  
Hui An ◽  
Jing Li ◽  
Amin Maghbouli ◽  
Kian Jon Chua
Keyword(s):  
Diesel Engine ◽  
Diesel Engines ◽  
Thermal Efficiency ◽  
Gasoline Engine ◽  
Combustion Process ◽  
Nox Emissions ◽  
Organic Additives ◽  
Oil Droplets ◽  
And Performance ◽  
One Year

Transportation is one of the major contributors to the world’s energy consumption and greenhouse gases emissions. The need for increased efficiency has placed diesel engine in the spotlight due to its superior thermal efficiency and fuel economy over gasoline engine. However, diesel engines also face the major disadvantage of increased NOx emissions. To address this issue, three types of emulsion fuels with different water concentrations (5%, 10% and 15% mass water) are produced and tested. Novel organic materials (glycerin and ployethoxy-ester) are added in the fuel to provide extra oxygen for improving combustion. NP-15 is added as surfactant which can help to reduce the oil and water surface tension, activates their surface, and maximizes their superficial contact areas, thereby forming a continuous and finely dispersed droplets phase. The stability of the emulsion fuels is tested under various environmental temperature for one year, and no significant separation is observed. It is better than normal emulsion fuel which can only maintain the state for up to three months. The combustion process and performance of the emulsion fuels are tested in a four-stroke, four cylinder diesel engine. The results indicate that the water droplets enclosed in the emulsion fuel explode at high temperature environment and help to break up the big oil droplets into smaller ones, thereby significantly increase the surface area of the oil droplets and enhance the heat transfer from hot gas to the fuel. As a result, the fuel evaporation is improved and the combustion process is accelerated, leading to an improved brake thermal efficiency (up to 14.2%). Meanwhile, the presence of the water causes the peak temperature of the flame to drop, thereby significantly bringing down the NOx emissions by more than 30%.

Diesel Engine Intake Condition Control-Oriented Models for Active Fuel Injection Profile Control

2011 ◽  
Author(s):  
Fengjun Yan ◽  
Junmin Wang
Keyword(s):  
Diesel Engine ◽  
Diesel Engines ◽  
Fuel Injection ◽  
Combustion Process ◽  
Exhaust Gas Recirculation ◽  
High Fidelity ◽  
Exhaust Gas ◽  
Engine Model ◽  
Profile Control ◽  
Gas Recirculation

Fueling control in Diesel engines is not only of significance to the combustion process in one particular cycle, but also influences the subsequent dynamics of air-path loop and combustion events, particularly when exhaust gas recirculation (EGR) is employed. To better reveal such inherently interactive relations, this paper presents a physics-based, control-oriented model describing the dynamics of the intake conditions with fuel injection profile being its input for Diesel engines equipped with EGR and turbocharging systems. The effectiveness of this model is validated by comparing the predictive results with those produced by a high-fidelity 1-D computational GT-Power engine model.

scholarly journals Experimental study of multiple pilot injection strategy in an automotive direct injection diesel engine

2018 ◽  
Vol 234 ◽  
pp. 03007
Author(s):  
Plamen Punov ◽  
Tsvetomir Gechev ◽  
Svetoslav Mihalkov ◽  
Pierre Podevin ◽  
Dalibor Barta
Keyword(s):  
Experimental Study ◽  
Diesel Engine ◽  
Diesel Engines ◽  
Direct Injection ◽  
Combustion Process ◽  
Injection Timing ◽  
Pilot Injection ◽  
Injection Strategy ◽  
Direct Injection Diesel Engine ◽  
Rate Of Heat Release

The pilot injection strategy is a widely used approach for reducing the noise of the combustion process in direct injection diesel engines. In the last generation of automotive diesel engines up to several pilot injections could occur to better control the rate of heat release (ROHR) in the cylinder as well as the pollutant formation. However, determination of the timing and duration for each pilot injection needs to be precisely optimised. In this paper an experimental study of the pilot injection strategy was conducted on a direct injection diesel engine. Single and double pilot injection strategy was studied. The engine rated power is 100 kW at 4000 rpm while the rated torque is 320 Nm at 2000 rpm. An engine operating point determined by the rotation speed of 1400 rpm and torque of 100 Nm was chosen. The pilot and pre-injection timing was widely varied in order to study the influence on the combustion process as well as on the fuel consumption.

Ion Current, Combustion and Emission Characteristics in an Automotive Common Rail Diesel Engine

2012 ◽  
Vol 134 (4) ◽  
Author(s):  
Naeim A. Henein ◽  
Tamer Badawy ◽  
Nilesh Rai ◽  
Walter Bryzik
Keyword(s):  
Diesel Engine ◽  
Diesel Engines ◽  
Direct Injection ◽  
Common Rail ◽  
Ion Current ◽  
Injection System ◽  
Feedback Signal ◽  
Common Rail Injection System ◽  
Common Rail Injection ◽  
No Emissions

Advanced electronically controlled diesel engines require a feedback signal to the ECU to adjust different operating parameters and meet demands for power, better fuel economy and low emissions. Different types of in-cylinder combustion sensors are being considered to produce this signal. This paper presents results of an experimental investigation on the characteristics of the ion current in an automotive diesel engine equipped with a common rail injection system. The engine is a 1.9 L, 4-cylinder, direct injection diesel engine. Experiments covered different engine loads and injection pressures. The relationships between the ion current, combustion parameters and engine out NO emissions and opacity are presented. The analysis of the experimental data identified possible sources of the ion current produced in diesel engines.

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