Diesel engine control optimization for transient operation with lean/rich switches

2003 ◽  
Vol 4 (3) ◽  
pp. 219-231 ◽  
Author(s):  
N. P. Kyrtatos ◽  
E. I. Tzanos ◽  
C. I. Papadopoulos
Keyword(s):  
Diesel Engine ◽  
Direct Injection ◽  
Optimization Procedure ◽  
Combustion Model ◽  
Transient Operation ◽  
Simulation Code ◽  
Engine Operation ◽  
Control Optimization ◽  
Management Schemes ◽  
Engine Components

Transient operation of a direct injection heavy duty (DI HD) diesel engine equipped with an NOx storage catalyst (NSC) was simulated using a ‘virtual powerplant’ simulation code with a zero-dimensional multizone combustion model. For the regeneration of the NSC the engine is required to work with lean/rich operation switches, which necessitates advanced engine management schemes for the fuelling, throttle and turbocharger wastegate. An optimization procedure, using the simulation model, resulted in a proposed schedule for the control of the various engine components involved in such engine operation.

Simulation of a Single Cylinder Diesel Engine Under Cold Start Conditions Using Simulink

2000 ◽  
Vol 123 (1) ◽  
pp. 117-124 ◽  
Author(s):  
H.-Q. Liu ◽  
N. G. Chalhoub ◽  
N. Henein
Keyword(s):  
Diesel Engine ◽  
Direct Injection ◽  
Cold Start ◽  
Operating Conditions ◽  
Combustion Model ◽  
Nonlinear Dynamic Model ◽  
Single Cylinder ◽  
Engine Model ◽  
Simulink Model ◽  
Engine Components

A nonlinear dynamic model is developed in this study to simulate the overall performance of a naturally aspirated, single cylinder, four-stroke, direct injection diesel engine under cold start and fully warmed-up conditions. The model considers the filling and emptying processes of the cylinder, blowby, intake, and exhaust manifolds. A single zone combustion model is implemented and the heat transfer in the cylinder, intake, and exhaust manifolds are accounted for. Moreover, the derivations include the dynamics of the crank-slider mechanism and employ an empirical model to estimate the instantaneous frictional losses in different engine components. The formulation is coded in modular form whereby each module, which represents a single process in the engine, is introduced as a single block in an overall Simulink engine model. The numerical accuracy of the Simulink model is verified by comparing its results to those generated by integrating the engine formulation using IMSL stiff integration routines. The engine model is validated by the close match between the predicted and measured cylinder gas pressure and engine instantaneous speed under motoring, steady-state, and transient cold start operating conditions.

Effects of the Injection Parameters on the Emissions of a Heavy Duty Diesel Engine

2009 ◽  
Author(s):  
M. Yılmaz ◽  
M. Zafer Gul ◽  
Y. Yukselenturk ◽  
B. Akay ◽  
H. Koten
Keyword(s):  
Diesel Engine ◽  
Direct Injection ◽  
Combustion Process ◽  
Design Parameters ◽  
Combustion Model ◽  
Particulate Emissions ◽  
Multiphase Model ◽  
Heavy Duty ◽  
Flow Development ◽  
Air Motion

It is estimated by the experts in the automotive industry that diesel engines on the transport market should increase within the years to come due to their high thermal efficiency coupled with low carbon dioxide (CO2) emissions, provided their nitrogen oxides (NOx) and particulate emissions are reduced. At present, adequate after-treatments, NOx and particulates matter (PM) traps are developed and industrialized with still concerns about fuel economy, robustness, sensitivity to fuel sulfur and cost because of their complex and sophisticated control strategy. New combustion processes focused on clean diesel combustion are investigated for their potential to achieve near zero particulate and NOx emissions. Their main drawbacks are increased level of unburned hydrocarbons (HC) and carbon monoxide (CO) emissions, combustion control at high load and limited operating range and power output. In this work, cold flow simulations for a single cylinder of a nine-liter (6 cylinder × 1.5 lt.) diesel engine have been performed to find out flow development and turbulence generation in the piston-cylinder assembly. In this study, the goal is to understand the flow field and the combustion process in order to be able to suggest some improvements on the in-cylinder design of an engine. Therefore combustion simulations of the engine have been performed to find out flow development and emission generation in the cylinder. Moreover, the interaction of air motion with high-pressure fuel spray injected directly into the cylinder has also been carried out. A Lagrangian multiphase model has been applied to the in-cylinder spray-air motion interaction in a heavy-duty CI engine under direct injection conditions. A comprehensive model for atomization of liquid sprays under high injection pressures has been employed. The combustion is modeled via a new combustion model ECFM-3Z (Extended Coherent Flame Model) developed at IFP. Finally, a calculation on an engine configuration with compression, spray injection and combustion in a direct injection Diesel engine is presented. Further investigation has also been performed in-cylinder design parameters in a DI diesel engine that result in low emissions by effect of high turbulence level. The results are widely in agreement qualitatively with the previous experimental and computational studies in the literature.

A Predictive Ignition Delay Correlation Under Steady-State and Transient Operation of a Direct Injection Diesel Engine

2003 ◽  
Vol 125 (2) ◽  
pp. 450-457 ◽  
Author(s):  
D. N. Assanis ◽  
Z. S. Filipi ◽  
S. B. Fiveland ◽  
M. Syrimis
Keyword(s):  
Steady State ◽  
Diesel Engine ◽  
Ignition Delay ◽  
Direct Injection ◽  
Thermodynamic Simulation ◽  
Injection Pressure ◽  
Transient Operation ◽  
Load Spectrum ◽  
Two Phase ◽  
Transient Conditions

Available correlations for the ignition delay in pulsating, turbulent, two-phase, reacting mixtures found in a diesel engine often have limited predictive ability, especially under transient conditions. This study focuses on the development of an ignition delay correlation, based on engine data, which is suitable for predictions under both steady-state and transient conditions. Ignition delay measurements were taken on a heavy-duty diesel engine across the engine speed/load spectrum, under steady-state and transient operation. The dynamic start of injection was calculated by using a skip-fire technique to determine the dynamic needle lift pressure from a measured injection pressure profile. The dynamic start of combustion was determined from the second derivative of measured cylinder pressure. The inferred ignition delay measurements were correlated using a modified Arrhenius expression to account for variations in fuel/air composition during transients. The correlation has been compared against a number of available correlations under steady-state conditions. In addition, comparisons between measurements and predictions under transient conditions are made using the extended thermodynamic simulation framework of Assanis and Heywood. It is concluded that the proposed correlation provides better predictive capability under both steady-state and transient operation.

Long Term Direct Injection Diesel Engine Operation on Vegetable Oil/Diesel Blends

2003 ◽  
Author(s):  
Nakorn Tippayawong ◽  
Anusan Permsuwan ◽  
Nat Vorayos ◽  
Tanongkiat Kiatsiriroat ◽  
Srithorn Uppakam ◽  
...  
Keyword(s):  
Diesel Engine ◽  
Vegetable Oil ◽  
Direct Injection ◽  
Engine Operation ◽  
Direct Injection Diesel Engine

scholarly journals Numerical-Experimental Comparison of the Performance of a Partially Stratified Charge Natural Gas Fuelled Engine

2004 ◽  
Author(s):  
Luca Andreassi ◽  
Stefano Cordiner ◽  
Vincenzo Mulone ◽  
C. Reynolds ◽  
R. L. Evans
Keyword(s):  
Natural Gas ◽  
Direct Injection ◽  
Numerical Data ◽  
Optimization Procedure ◽  
Complete Information ◽  
Experimental Comparison ◽  
Combustion Model ◽  
Stratified Charge ◽  
Spark Plug ◽  
Reduce Emissions

Compressed natural gas (CNG) has great potential as an alternative fuel for vehicle engines, and can reduce emissions and improve fuel economy. A single cylinder research engine has been modified to enable direct injection of a small quantity of fuel near the spark plug, independently of an overall lean homogeneous charge. Thus a partially stratified charge is formed within the chamber, which allows significant extension of the lean limit of combustion. This results in an improvement in specific fuel consumption. Numerical simulation also plays an important role in the development of such technological solutions. 3D simulations, in particular, are desirable to provide complete information about thermal and fluid dynamical fields within the chamber. In particular, among the developed numerical tools linked to the KIVA-3V code, special attention was dedicated to the formulation of the combustion model (CFM) turbulent combustion model based on the flamelet hypothesis), to adequately model non-homogeneities and lean mixture compositions. In this paper an optimization procedure is assessed, with the ultimate goal of designing combustion chambers properly devoted to be operated under lean (homogeneous and PSC) mixture conditions. The results related to the procedure definition and to its experimental validation are presented. Experimental and numerical data have been compared in terms of pressure cycles and heat release rate profiles. The overall results are encouraging, taking into special account the difficulty to reliably predict the key performance parameters without any “tuning interventions”, even when mixture richness and homogeneity were varied.

Combustion Model for a Homogeneous Turbocharged Gasoline Direct-Injection Engine

2018 ◽  
Vol 140 (10) ◽  
Author(s):  
Sedigheh Tolou ◽  
Ravi Teja Vedula ◽  
Harold Schock ◽  
Guoming Zhu ◽  
Yong Sun ◽  
...  
Keyword(s):  
Heat Release ◽  
Direct Injection ◽  
Operation Mode ◽  
Gasoline Direct Injection ◽  
Combustion Model ◽  
Combustion Heat ◽  
Engine Operation ◽  
Release Analysis ◽  
Gdi Engine ◽  
Homogeneous Charge

Homogeneous charge is a preferred operation mode of gasoline direct-injection (GDI) engines. However, a limited amount of work exists in the literature for combustion models of this mode of engine operation. Current work describes a model developed to study combustion in a homogeneous charge GDI engine. The model was validated using experimental data from a 1.6 L Ford EcoBoost® engine, tested at the U.S. EPA. The combustion heat release was approximated using a double-Wiebe function, to account for the rapid initial premixed combustion followed by a gradual diffusion-like state of combustion, as observed in this GDI engine. Variables of Wiebe correlations were adjusted into a semipredictive combustion model. The effectiveness of semipredictive combustion model was tested in prediction of in-cylinder pressures. The root-mean-square (RMS) errors between experiments and numerical results were within 2.5% of in-cylinder peak pressures during combustion. The semipredictive combustion model was further studied to develop a predictive combustion model. The performance of predictive combustion model was examined by regenerating the experimental cumulative heat release. The heat release analysis developed for the GDI engine was further applied to a dual mode, turbulent jet ignition (DM-TJI) engine. DM-TJI is a distributed combustion technology with the potential to provide diesel-like efficiencies and minimal engine-out emissions for spark-ignition engines. The DM-TJI engine was observed to offer a faster burn rate and lower in-cylinder heat transfer compared to the GDI engine.

A CFD Study on Heavy Duty DI Diesel Engine to Achieve Ultra-Low Emissions

2010 ◽  
Author(s):  
M. Yilmaz ◽  
H. Koten ◽  
M. Zafer Gul
Keyword(s):  
Diesel Engine ◽  
Cfd Simulation ◽  
Combustion Engine ◽  
Direct Injection ◽  
Spray Angle ◽  
Combustion Model ◽  
Multiphase Model ◽  
Heavy Duty ◽  
Start Of Injection ◽  
Main Injection

Nowadays, automotive industries focused on clean diesel combustion in their combustion processes are investigated for their potential to achieve near zero particulate and NOx (Nitrogen oxides) emissions. Their main disadvantages are increased level of unburned hydrocarbons (HC) and carbon monoxide (CO) emissions, combustion control at high load, power output and limited operating range. The simulation of the air flow, spray and combustion in an internal combustion engine were prepared for a single cylinder of a nine-liter, six cylinder diesel engine. Many times the geometry is complex because moving pistons and valves are involved, which makes it difficult to generate structured mesh. In-cylinder spray-air motion interaction, a Lagrangian multiphase model has been applied in a heavy-duty CI engine under direct injection conditions. A comprehensive model for atomization of liquid sprays under high injection pressures has been employed. Three dimensional CFD calculations of the intake, compression and power strokes have been carried out with different spray angle, spray profile and start of injection. A new combustion model ECFM-3Z (Extended Coherent Flame Model) developed at IFP is used for combustion modeling. Finally, a calculation on an engine configuration with compression, spray injection and combustion in a direct injection Diesel engine is presented. In this study, exhaust emissions, and particularly the emission of NOx, CO and soot derived from premixed combustion are investigated, and the relationship between combustion and emission characteristics are showed. The calculated CFD simulation in different combustion cases was compared. The cases were prepared by changing the parameters: start of injection, spray angle and spray profile. Modeling of combustion proposed in the present study can be outlined as follows. NOx concentration is decreased by combustion of a over lean-mixture modeled by the pre-injection. Most of pre-mixture is combusted by main-injection, and therefore the amount of pre-injection and main-injection come into prominence. The results are greatly in agreement qualitatively with the previous experimental and computational studies in the literature.

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