A Control-Oriented Reaction-Based SI Engine Combustion Model

2018 ◽  
Author(s):  
Ruixue C. Li ◽  
Guoming G. Zhu
Keyword(s):  
Chemical Reaction ◽  
Mass Fraction ◽  
Combustion Process ◽  
Combustion Model ◽  
Spark Ignition Engines ◽  
Si Engine ◽  
Chemical Reaction Mechanism ◽  
Engine Combustion ◽  
Rate Of Heat Release ◽  
Mass And Heat Transfer

This paper proposes a control-oriented chemical reaction-based two-zone combustion model designed to accurately describe the combustion process and thermal performance for spark-ignition engines. The combustion chamber is assumed to be divided into two zones: reaction and unburned zones, where the chemical reaction takes place in the reaction zone and the unburned zone contains all the unburned mixture. In contrast to the empirical pre-determined Wiebe-function-based combustion model, an ideal two-step chemical reaction mechanism is used to reliably model the detailed combustion process such as mass-fraction-burned (MFB) and rate of heat release. The interaction between two zones includes mass and heat transfer at the zone interface to have a smooth combustion process. This control-oriented model is extensively calibrated based on the experimental data to demonstrate its capability of predicting the combustion process and thermodynamic states of the in-cylinder mixture.

scholarly journals Possibilities to identify engine combustion model parameters by analysis of the instantaneous crankshaft angular speed

2014 ◽  
Vol 18 (1) ◽  
pp. 97-112 ◽  
Author(s):  
Slobodan Popovic ◽  
Miroljub Tomic
Keyword(s):  
Combustion Process ◽  
Nonlinear Least Squares ◽  
Angular Speed ◽  
Spark Ignition Engine ◽  
Combustion Model ◽  
Model Parameters ◽  
Si Engine ◽  
Engine Combustion ◽  
Novel Method ◽  
Engine Crankshaft

In this paper, novel method for obtaining information about combustion process in individual cylinders of a multi-cylinder Spark Ignition Engine based on instantaneous crankshaft angular velocity is presented. The method is based on robust box constrained Levenberg-Marquardt minimization of nonlinear Least Squares given for measured and simulated instantaneous crankshaft angular speed which is determined from the solution of the engine dynamics torque balance equation. Combination of in-house developed comprehensive Zero-Dimensional Two-Zone SI engine combustion model and analytical friction loss model in angular domain have been applied to provide sensitivity and error analysis regarding Wiebe combustion model parameters, heat transfer coefficient and compression ratio. The analysis is employed to evaluate the basic starting assumption and possibility to provide reliable combustion analysis based on instantaneous engine crankshaft angular speed.

Estimation of Wiebe Function Parameters for Syngas and Anode Off-Gas Combustion in Spark-Ignition Engines

2021 ◽  
Author(s):  
Ruinan Yang ◽  
Zhongnan Ran ◽  
Dimitris Assanis
Keyword(s):  
Combustion Process ◽  
Fuel Mixture ◽  
Spark Ignition ◽  
Spark Ignition Engines ◽  
Si Engine ◽  
Gas Combustion ◽  
Engine Combustion ◽  
Comparable Accuracy ◽  
Fuel Mass Fraction ◽  
Wiebe Function

Abstract Wiebe functions, analytical equations that estimate the fuel mass fraction burned (MFB) during combustion, have been effective at describing spark-ignition (SI) engine combustion using gasoline fuels. This study explores if the same methodology can be extended for SI combustion with syngas, a gaseous fuel mixture composed of H2, CO, and CO2, and anode-off gas; the latter is an exhaust gas mixture emitted from the anode of a Solid Oxide Fuel Cell, containing H2, CO, H2O, and CO2. For this study, anode off-gas is treated as a syngas fuel diluted with CO2 and vaporized water. Combustion experiments were run on a single-cylinder, research engine using syngas and anode-off gas as fuels. One single Wiebe function and three double Wiebe functions were fitted and compared with the MFB profile calculated from the experimental data. It was determined that the SI combustion process of both the syngas and the anode-off gas could be estimated using a governing Wiebe function. While the detailed double Wiebe function had the highest accuracy, a reduced double Wiebe function is capable of achieving comparable accuracy. On the other hand, a single Wiebe function is not able to fully capture the combustion process of a SI engine using syngas and anode off-gas.

scholarly journals Numerical Study of Engine Performance and Emissions for Port Injection of Ammonia into a Gasoline\Ethanol Dual-Fuel Spark Ignition Engine

2021 ◽  
Vol 11 (4) ◽  
pp. 1441
Author(s):  
Farhad Salek ◽  
Meisam Babaie ◽  
Amin Shakeri ◽  
Seyed Vahid Hosseini ◽  
Timothy Bodisco ◽  
...  
Keyword(s):  
Numerical Study ◽  
Combustion Process ◽  
Engine Performance ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Combustion Model ◽  
Dual Fuel ◽  
Spark Ignition Engines ◽  
Performance And Emissions ◽  
Hc Emissions

This study aims to investigate the effect of the port injection of ammonia on performance, knock and NOx emission across a range of engine speeds in a gasoline/ethanol dual-fuel engine. An experimentally validated numerical model of a naturally aspirated spark-ignition (SI) engine was developed in AVL BOOST for the purpose of this investigation. The vibe two zone combustion model, which is widely used for the mathematical modeling of spark-ignition engines is employed for the numerical analysis of the combustion process. A significant reduction of ~50% in NOx emissions was observed across the engine speed range. However, the port injection of ammonia imposed some negative impacts on engine equivalent BSFC, CO and HC emissions, increasing these parameters by 3%, 30% and 21%, respectively, at the 10% ammonia injection ratio. Additionally, the minimum octane number of primary fuel required to prevent knock was reduced by up to 3.6% by adding ammonia between 5 and 10%. All in all, the injection of ammonia inside a bio-fueled engine could make it robust and produce less NOx, while having some undesirable effects on BSFC, CO and HC emissions.

A Control-Oriented Jet Ignition Combustion Model for an SI Engine

2015 ◽  
Author(s):  
Ruitao Song ◽  
Gerald Gentz ◽  
Guoming Zhu ◽  
Elisa Toulson ◽  
Harold Schock
Keyword(s):  
Combustion Chamber ◽  
Combustion Process ◽  
Turbulent Jets ◽  
Combustion Stability ◽  
Combustion Model ◽  
Combustion Chambers ◽  
Si Engine ◽  
Lean Operations ◽  
Combustion Processes ◽  
Hil Simulation

A turbulent jet ignition system of a spark ignited (SI) engine consists of pre-combustion and main-combustion chambers, where the combustion in the main-combustion chamber is initiated by turbulent jets of reacting products from the pre-combustion chamber. If the gas exchange and combustion processes are accurately controlled, the highly distributed ignition will enable very fast combustion and improve combustion stability under lean operations, which leads to high thermal efficiency, knock limit extension, and near zero NOx emissions. For model-based control, a precise combustion model is a necessity. This paper presents a control-oriented jet ignition combustion model, which is developed based on simplified fluid dynamics and thermodynamics, and implemented into a dSPACE based real-time hardware-in-the-loop (HIL) simulation environment. The two-zone combustion model is developed to simulate the combustion process in two combustion chambers. Correspondingly, the gas flowing through the orifices between two combustion chambers is divided into burned and unburned gases during the combustion process. The pressure traces measured from a rapid compression machine (RCM), equipped with a jet igniter, are used for initial model validation. The HIL simulation results show a good agreement with the experimental data.

Studying the effects of hydrogen addition on the second-law balance of a biogas-fuelled spark ignition engine by use of a quasi-dimensional multi-zone combustion model

2008 ◽  
Vol 222 (11) ◽  
pp. 2249-2268 ◽  
Author(s):  
C D Rakopoulos ◽  
C N Michos ◽  
E G Giakoumis
Keyword(s):  
Combustion Process ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Combustion Model ◽  
Second Law ◽  
Si Engine ◽  
Engine Operation ◽  
Hydrogen Addition ◽  
Cycle Simulation ◽  
Hydrogen Enrichment

Although a first-law analysis can show the improvement that hydrogen addition impacts on the performance of a biogas-fuelled spark-ignition (SI) engine, additional benefits can be revealed when the second law of thermodynamics is brought into perspective. It is theoretically expected that hydrogen enrichment in biogas can increase the second-law efficiency of engine operation by reducing the combustion-generated irreversibilities, because of the fundamental differences in the mechanism of entropy generation between hydrogen and traditional hydrocarbon combustion. In this study, an experimentally validated closed-cycle simulation code, incorporating a quasi-dimensional multi-zone combustion model that is based on the combination of turbulent entrainment theory and flame stretch concepts for the prediction of burning rates, is further extended to include second-law analysis for the purpose of quantifying the respective improvements. The analysis is applied for a single-cylinder homogeneous charge SI engine, fuelled with biogas—hydrogen blends, with up to 15 vol% hydrogen in the fuel mixture, when operated at 1500r/min, wide-open throttle, fuel-to-air equivalence ratio of 0.9, and ignition timing of 20° crank angle before top dead centre. Among the major findings derived from the second-law balance during the closed part of the engine cycle is the increase in the second-law efficiency from 40.85 per cent to 42.41 per cent with hydrogen addition, accompanied by a simultaneous decrease in the combustion irreversibilities from 18.25 per cent to 17.18 per cent of the total availability of the charge at inlet valve closing. It is also illustrated how both the increase in the combustion temperatures and the decrease in the combustion duration with increasing hydrogen content result in a reduction in the combustion irreversibilities. The degree of thermodynamic perfection of the combustion process from the second-law point of view is quantified by using two (differently defined) combustion exergetic efficiencies, whose maximum values during the combustion process increase with hydrogen enrichment from 49.70 per cent to 53.45 per cent and from 86.01 per cent to 87.33 per cent, respectively.

scholarly journals A Two-Zone Multigrid Model for SI Engine Combustion Simulation Using Detailed Chemistry

2010 ◽  
Vol 2010 ◽  
pp. 1-12 ◽  
Author(s):  
Hai-Wen Ge ◽  
Harmit Juneja ◽  
Yu Shi ◽  
Shiyou Yang ◽  
Rolf D. Reitz
Keyword(s):  
Direct Injection ◽  
Equation Model ◽  
Gasoline Direct Injection ◽  
Combustion Model ◽  
Si Engine ◽  
Detailed Chemistry ◽  
Combustion Modeling ◽  
Engine Simulation ◽  
Engine Combustion ◽  
Order Of Magnitude

An efficient multigrid (MG) model was implemented for spark-ignited (SI) engine combustion modeling using detailed chemistry. The model is designed to be coupled with a level-set-G-equation model for flame propagation (GAMUT combustion model) for highly efficient engine simulation. The model was explored for a gasoline direct-injection SI engine with knocking combustion. The numerical results using the MG model were compared with the results of the original GAMUT combustion model. A simpler one-zone MG model was found to be unable to reproduce the results of the original GAMUT model. However, a two-zone MG model, which treats the burned and unburned regions separately, was found to provide much better accuracy and efficiency than the one-zone MG model. Without loss in accuracy, an order of magnitude speedup was achieved in terms of CPU and wall times. To reproduce the results of the original GAMUT combustion model, either a low searching level or a procedure to exclude high-temperature computational cells from the grouping should be applied to the unburned region, which was found to be more sensitive to the combustion model details.

A Comparative Study of Combustion Models for Spark Ignition Engines Based on Experimentation and CFD Simulation

2010 ◽  
Author(s):  
Raouf Mobasheri ◽  
M. Sadegh Shahrokhi-Dehkordi
Keyword(s):  
Comparative Study ◽  
Cfd Simulation ◽  
Combustion Process ◽  
Experimental Tests ◽  
Experimental Results ◽  
Nox Emission ◽  
Combustion Model ◽  
Spark Ignition Engines ◽  
Flamelet Model ◽  
Combustion Models

Computational fluid dynamics (CFD) is able to significantly reduce the number of experimental tests and measurements and lower the development time and costs. However some parameters which are needed for CFD calculation must be achieved experimentally. In this paper, a comparative study was carried out to clarify the effect of three different combustion models on the prediction capability of combustion process and NOx emission on a modified 4-cylinder MPFI SI engine. Validation of the combustion model has been performed through comparing simulation data with the experimental results and a satisfactory agreement between them has been achieved in terms of combustion parameters and NOx emission. The results show that, applying appropriate constants of each combustion model including Eddy break up model (Ebu), Probability density function (Pdf) and Coherent flamelet model (Cfm) causes the computational results to be in agreement with experimental results. Furthermore the results show that the nearest prediction in comparison with experimental results is by applying the Ebu model.

scholarly journals Acoustic Study of an Air Intake System of SI Engine using 1-Dimensional Approach

2019 ◽  
Vol 16 (1) ◽  
pp. 6281-6300
Author(s):  
A. A. Dahlan ◽  
Mohd Farid Muhammad Said ◽  
Z. Abdul Latiff ◽  
M. R. Mohd Perang ◽  
S. A. Abu Bakar ◽  
...  
Keyword(s):  
Combustion Engine ◽  
Combustion Process ◽  
Main Role ◽  
Si Engine ◽  
Intake System ◽  
Acoustic Study ◽  
Engine Combustion ◽  
Physical Testing ◽  
Air Intake ◽  
Dimensional Simulation

Air intake system of an internal combustion engine plays main role in delivering fresh air from the environment to the engine and dampening the sound of the engine combustion process coming from the engine combustion process. In this study, a simulation was conducted to improve the existing air intake system design in terms of acoustic study to have better sound quality by modifying the resonators, air duct and airbox volume of the air intake module. This study implements the 1-dimensional simulation study using commercial software, correlate to the 1.6-liter natural aspirated engine. The objective of this study is to decrease the engine noise at snorkel of the air intake module without losing too much of pressure drop. At the end of this study, the analysis defines the geometry of air intake module with the recommended resonator for fabrication and physical testing. The simulation result shows that the modified air intake module meet the objective and fulfil the performance target.

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