Analysis of Incylinder Pressure and Temperature Variation in a Four-Stroke S. I. Engine Using Wiebe’s Combustion Model

2014 ◽  
Vol 984-985 ◽  
pp. 957-961
Author(s):  
Vijayashree ◽  
P. Tamil Porai ◽  
N.V. Mahalakshmi ◽  
V. Ganesan
Keyword(s):  
Heat Release ◽  
Combustion Process ◽  
Pressure Variation ◽  
Spark Ignition Engine ◽  
Working Fluid ◽  
Combustion Model ◽  
Cylinder Pressure ◽  
Crank Angle ◽  
Experimental Values ◽  
Release Model

This paper presents the modeling of in-cylinder pressure variation of a four-stroke single cylinder spark ignition engine. It uses instantaneous properties of working fluid, viz., gasoline to calculate heat release rates, needed to quantify combustion development. Cylinder pressure variation with respect to either volume or crank angle gives valuable information about the combustion process. The analysis of the pressure – volume or pressure-theta data of a engine cycle is a classical tool for engine studies. This paper aims at demonstrating the modeling of pressure variation as a function of crank angle as well as volume with the help of MATLAB program developed for this purpose. Towards this end, Woschni heat release model is used for the combustion process. The important parameter, viz., peak pressure for different compression ratios are used in the analysis. Predicted results are compared with experimental values obtained for a typical compression ratio of 8.3.

A two-zone reaction-based combustion model for a spark-ignition engine

2019 ◽  
Vol 22 (1) ◽  
pp. 109-124 ◽  
Author(s):  
Ruixue C Li ◽  
Guoming G Zhu ◽  
Yifan Men
Keyword(s):  
Real Time ◽  
Combustion Process ◽  
Operating Conditions ◽  
Spark Ignition Engine ◽  
Combustion Model ◽  
Individual Species ◽  
Cylinder Pressure ◽  
Model Based ◽  
Modeling Approach ◽  
Real Time Simulations

This article presents a control-oriented two-zone reaction-based zero-dimensional model to accurately describe the combustion process of a spark-ignited engine for real-time simulations, and the developed model will be used for model-based control design and validation. A two-zone modeling approach is adopted, where the combustion chamber is divided into the burned (reaction) and unburned (pre-mixed) zones. The mixture thermodynamic properties and individual chemical species in two zones are taken into account in the modeling process. Instead of using the conventional pre-determined Wiebe-based combustion model, a two-step chemical reaction model is utilized to predict the combustion process along with important thermodynamic parameters such as the mass-fraction-burned, in-cylinder pressure, temperatures, and individual species mass changes in both zones. Sensitivities of model parameters are analyzed during the model calibration process. As a result, one set of calibration parameters is used to predict combustion characteristics over all engine operating conditions studied in this article, which is the major advantage of the proposed method. Also, the proposed modeling approach is capable of modeling the combustion process under different air-to-fuel ratios, ignition timings, and exhaust-gas-recirculation rates for real-time simulations. As the by-product of the model, engine knock can also be predicted based on the Arrhenius integral in the unburned zone, which is valuable for model-based knock control. The proposed combustion model is intensively validated using the experimental data with a peak relative prediction error of 6.2% for the in-cylinder pressure.

Thermodynamic Modeling of Single Cylinder Direct Injection Compression Ignition Engine in Simulink

2015 ◽  
Vol 813-814 ◽  
pp. 866-873
Author(s):  
Sindhu Ravichettu ◽  
G. Amba Prasad Rao ◽  
K. Madhu Murthy
Keyword(s):  
Heat Release ◽  
Direct Injection ◽  
Combustion Process ◽  
Combustion Model ◽  
Compression Ignition ◽  
Compression Ignition Engine ◽  
Close Match ◽  
Tuning Parameters ◽  
Crank Angle ◽  
Diesel Cycle

The aim of this research is to develop a mathematical model of a compression ignition engine using cylinder-by-cylinder model approach to predict the performances; indicated work, indicated torque, in-cylinder pressures and temperatures and heat release rates. The method used in the study is based on ideal diesel cycle and is modified by the numerical formulations which affect the performance of the engine. The model consists of a set of tuning parameters such as engine geometries, EGR fractions, boost pressures, injection timings, air/fuel ratio, etc. It is developed in Simulink environment to promote modularity. A single-zone combustion model is developed and implemented for the combustion process which accounts for ignition delay, heat release. Derivations from slider-crank mechanism are involved to compute the instantaneous volume, area and stroke at any given crank angle. The results of the simulation model have been validated with experimental results with a close match between them.

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.

Model-Based Combustion Duration and Ignition Timing Prediction for Combustion Phasing Control of a Spark-Ignition Engine Using In-Cylinder Pressure Sensors

2019 ◽  
Author(s):  
Xin Wang ◽  
Amir Khameneian ◽  
Paul Dice ◽  
Bo Chen ◽  
Mahdi Shahbakhti ◽  
...  
Keyword(s):  
Pressure Sensors ◽  
Spark Ignition ◽  
Operating Conditions ◽  
Spark Ignition Engine ◽  
Combustion Model ◽  
Ignition Timing ◽  
Model Based ◽  
Crank Angle ◽  
Si Engines ◽  
Phasing Control

Abstract Combustion phasing, which can be defined as the crank angle of fifty percent mass fraction burned (CA50), is one of the most important parameters affecting engine efficiency, torque output, and emissions. In homogeneous spark-ignition (SI) engines, ignition timing control algorithms are typically map-based with several multipliers, which requires significant calibration efforts. This work presents a framework of model-based ignition timing prediction using a computationally efficient control-oriented combustion model for the purpose of real-time combustion phasing control. Burn duration from ignition timing to CA50 (ΔθIGN-CA50) on an individual cylinder cycle-by-cycle basis is predicted by the combustion model developed in this work. The model is based on the physics of turbulent flame propagation in SI engines and contains the most important control parameters, including ignition timing, variable valve timing, air-fuel ratio, and engine load mostly affected by combination of the throttle opening position and the previous three parameters. With 64 test points used for model calibration, the developed combustion model is shown to cover wide engine operating conditions, thereby significantly reducing the calibration effort. A Root Mean Square Error (RMSE) of 1.7 Crank Angle Degrees (CAD) and correlation coefficient (R2) of 0.95 illustrates the accuracy of the calibrated model. On-road vehicle testing data is used to evaluate the performance of the developed model-based burn duration and ignition timing algorithm. When comparing the model predicted burn duration and ignition timing with experimental data, 83% of the prediction error falls within ±3 CAD.

Study on the Combustion Characteristics of the Engine Fueled with DME-Diesel Blends

2014 ◽  
Vol 953-954 ◽  
pp. 1381-1385
Author(s):  
Wei Li ◽  
Yun Peng Li ◽  
Fan Bin Li
Keyword(s):  
Heat Release ◽  
Pressure Rise ◽  
Mechanical Efficiency ◽  
Diesel Oil ◽  
Cylinder Pressure ◽  
Mass Ratio ◽  
Combustion Duration ◽  
Crank Angle ◽  
Maximum Combustion Temperature ◽  
Stroke Engine

To further study the performance of the engine fueled with DME-diesel blends, the indicator diagrams of a two-cylinder four-stroke engine are recorded at 1700r/min and 2300r/min under different load, the heat release rate and the rate of pressure rise are calculated. The results show that: when fueled the engine with D20 blend (Mass ratio of DME and diesel oil is 2:10) and optimizing the fuel supply advance angle, the maximum cylinder pressure decreases by 10% averagely and its corresponding crank angle delays 2°CA, the maximum rate of pressure rise is relatively lowers about 20%, the beginning of heat release delays，but combustion duration do not extend, and the centroid of heat release curves is closer to TDC (Top Dead Center), maximum combustion temperature drops 70-90K. These results indicate that the mechanical efficiency will be improved and, NOx emissions and mechanical noise will be reduced when an engine fueled with DME-diesel blends.

Combustion in a high-speed rotary valve spark-ignition engine

2007 ◽  
Vol 221 (8) ◽  
pp. 971-990 ◽  
Author(s):  
P H P Chow ◽  
H C Watson ◽  
T Wallis
Keyword(s):  
High Speed ◽  
Combustion Process ◽  
Spark Ignition Engine ◽  
Combustion Model ◽  
Rotary Valve ◽  
Combustion Simulation ◽  
Parametric Effects ◽  
Sensitivity Studies ◽  
Valve Engine ◽  
Data Sensitivity

The current paper describes a study of combustion in the Bishop rotary valve engine by means of computation simulations. The combustion model was developed for this research at speeds up to 18 000 r/min and the results from the simulation were compared with experimental data. Sensitivity studies were performed in order to investigate the parametric effects on the combustion simulation of the engine. The major finding of this study was that convection of the flame kernels occurs and has a strong influence on the performance of the engine. The results indicated some insights as to how the combustion process of the engine can be improved.

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.

Influence of piston bowl geometry on combustion and emission characteristics

2019 ◽  
Vol 233 (5) ◽  
pp. 576-587 ◽  
Author(s):  
Ramazan Şener ◽  
Mehmed R Özdemir ◽  
Murat U Yangaz
Keyword(s):  
Heat Release ◽  
Renewable Energy Sources ◽  
Combustion Characteristics ◽  
Emission Rates ◽  
Cylinder Pressure ◽  
Compression Ignition Engine ◽  
Piston Bowl ◽  
Crank Angle ◽  
Rate Of Heat Release ◽  
Exhaust Valves

Together with the global energy concerns, the norms are getting stringent to prevent the emission threat. There are on-going studies on systems working with both fossil and renewable energy sources aiming to create more efficient and less emissive processes and devices. Accordingly, a set of numerical simulations was performed to examine the effect of the bowl shape of a piston on the performance behaviour, emission rates and combustion characteristics in a four-cylinder, four strokes, water-cooled compression ignition engine using n-heptane (C7H16) as fuel. Six different piston bowl geometries, five from the literature and proposed one, were utilized having different length-to-diameter ratio, curvature and sidewall radius. The study was conducted at 1750 r/min engine speed and a constant compression ratio with a full performance condition. The intake and exhaust valves have been considered as closed during the analysis to provide the variation of crank angle from 300 CA to 495 CA. The results showed that the piston bowl geometry has a significant impact on the rate of heat release, in-cylinder pressure, in-cylinder temperature, and emission trends in the engine. Among the piston bowl geometries studied, design DE and design DF exhibited better combustion characteristics and relatively lower emission trends compared to other designs. The observed rate of heat release, in-cylinder pressure and in-cylinder temperature magnitudes of these two geometries was higher in comparison to other geometries. Moreover, the trade-off for NOx emission was also observed higher for these piston bowl designs.

Cylinder Specific Pressure Predictions for Advanced Dual Fuel Compression Ignition Engines Utilizing a Two-Stage Functional Data Analysis

2019 ◽  
Vol 141 (5) ◽  
Author(s):  
Xiao Huang ◽  
Lulu Kang ◽  
Mateos Kassa ◽  
Carrie Hall
Keyword(s):  
Combustion Process ◽  
Operating Parameter ◽  
Combustion Model ◽  
Dual Fuel ◽  
Compression Ignition ◽  
Cylinder Pressure ◽  
Specific Pressure ◽  
Compression Ignition Engine ◽  
Two Stage ◽  
Pressure Trace

In-cylinder pressure is a critical metric that is used to characterize the combustion process of engines. While this variable is measured on many laboratory test beds, in-cylinder pressure transducers are not common on production engines. As such, accurate methods of predicting the cylinder pressure have been developed both for modeling and control efforts. This work examines a cylinder-specific pressure model for a dual fuel compression ignition engine. This model links the key engine input variables to the critical engine outputs including indicated mean effective pressure (IMEP) and peak pressure. To identify the specific impact of each operating parameter on the pressure trace, a surrogate model was produced based on a functional Gaussian process (GP) regression approach. The pressure trace is modeled as a function of the operating parameters, and a two-stage estimation procedure is introduced to overcome various computational challenges. This modeling method is compared to a commercial dual fuel combustion model and shown to be more accurate and less computationally intensive.

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