scholarly journals Evaluation of residual gas fraction estimation methods for cycle-to-cycle combustion variability analysis and modeling

2021 ◽  
pp. 146808742098308
Author(s):  
Bryan P Maldonado ◽  
Brian C Kaul
Keyword(s):  
Combustion Process ◽  
Operating Conditions ◽  
Normal Operation ◽  
Estimation Methods ◽  
Spark Ignition Engines ◽  
Complete Combustion ◽  
Advantages And Disadvantages ◽  
Field Homogeneity ◽  
Residual Gas Fraction ◽  
Residual Gas

Cycle-to-cycle combustion variability in spark-ignition engines during normal operation is mainly caused by random perturbations of the in-cylinder conditions such as the flow velocity field, homogeneity of the air-fuel distribution, spark energy discharge, and turbulence intensity of the flame front. Such perturbations translate into the variability of the energy released observed at the end of the combustion process. During normal operating conditions, the cycle-to-cycle variability (CCV) of the energy release behaves as random uncorrelated noise. However, during diluted combustion, in either the form of exhaust gas recirculation (EGR) or excess air (lean operation), the CCV tends to increase as dilution increases. Moreover, when the ignition limit is reached at high dilution levels, the combustion CCV is exacerbated by sporadic occurrences of incomplete combustion events, and the uncorrelation assumption no longer holds. The low or null energy released by partial burns and misfires has an impact on the following combustion event due to the residual gas that carries burned and unburned gases, which contributes to the deterministic coupling between engine cycles. Many residual gas fraction estimation methods, however, only address the nominal case where complete combustion occurs and combustion events are uncorrelated. This study evaluates the efficacy of such methods on capturing the effects of partial burns and misfires on the residual gas estimate for high-EGR operation. The advantages and disadvantages of each method are discussed based on their ability to generate cycle-to-cycle estimates. Finally, a comparison between the different estimation techniques is presented based on their usefulness for control-oriented modeling.

Observer-Based Cylinder Air Charge Estimation for Spark-Ignition Engines

2017 ◽  
Vol 139 (10) ◽  
Author(s):  
Zhe Wang ◽  
Qilun Zhu ◽  
Robert Prucka ◽  
Michael Prucka ◽  
Hussein Dourra
Keyword(s):  
Steady State ◽  
Rapid Prototype ◽  
Spark Ignition ◽  
Operating Conditions ◽  
Spark Ignition Engine ◽  
Estimation Methods ◽  
Absolute Pressure ◽  
Spark Ignition Engines ◽  
Engine Torque ◽  
Advantages And Disadvantages

Spark-ignition engine in-cylinder air charge estimation is important for air-to-fuel ratio (AFR) control, maintaining high after-treatment efficiency, and determination of current engine torque. Current cylinder air charge estimation methodologies generally depend upon either a mass air flow (MAF) sensor or a manifold absolute pressure (MAP) sensor individually. Methods based on either sensor have their own advantages and disadvantages. Some production vehicles are equipped with both MAF and MAP sensors to offer air charge estimation and other benefits. This research proposes several observer-based cylinder air charge estimation methods that take advantage of both MAF and MAP sensors to potentially reduce calibration work while providing acceptable transient and steady-state accuracy with low computational load. This research also compares several common air estimation methods with the proposed observer-based algorithms using steady-state and transient dynamometer tests and a rapid-prototype engine controller. With appropriate tuning, the proposed observer-based methods are able to estimate cylinder air charge mass under different engine operating conditions based on the manifold model and available sensors. Methods are validated and compared based on a continuous tip-in tip-out operating condition.

Observer Based Cylinder Air Charge Estimation for Spark Ignition Engines

2016 ◽  
Author(s):  
Zhe Wang ◽  
Qilun Zhu ◽  
Robert Prucka ◽  
Michael Prucka ◽  
Hussein Dourra
Keyword(s):  
Steady State ◽  
Rapid Prototype ◽  
Spark Ignition ◽  
Operating Conditions ◽  
Spark Ignition Engine ◽  
Estimation Methods ◽  
Absolute Pressure ◽  
Spark Ignition Engines ◽  
Engine Torque ◽  
Advantages And Disadvantages

Spark ignition engine in-cylinder air charge estimation is important for air-to-fuel ratio control, maintaining high after-treatment efficiency, and determination of current engine torque. Current cylinder air charge estimation methodologies generally depend upon either a mass air flow (MAF) sensor or a manifold absolute pressure (MAP) sensor individually. Methods based on either sensor have their own advantages and disadvantages. Some production vehicles are equipped with both MAF and MAP sensors to offer air charge estimation and other benefits. This research proposes several observer based cylinder air charge estimation methods that take advantage of both MAF and MAP sensors to potentially reduce calibration work while providing acceptable transient and steady-state accuracy with low computational load. This research also compares several common air estimation methods with the proposed observer based algorithms using steady-state and transient dynamometer tests and a rapid-prototype engine controller. With appropriate tuning the proposed observer based methods are able to estimate cylinder air charge mass under different engine operating conditions based on the manifold model and available sensors. Methods are validated and compared based on a continuous tip-in tip-out operating condition.

Experimental Study of a Hydrogen-Fueled Engine

2000 ◽  
Vol 123 (1) ◽  
pp. 211-216 ◽  
Author(s):  
R. Sierens ◽  
S. Verhelst
Keyword(s):  
Combustion Process ◽  
Injection Pressure ◽  
Fuel Mixture ◽  
Operating Conditions ◽  
Lubricating Oil ◽  
Intake Manifold ◽  
Special Focus ◽  
Injection Timing ◽  
Complete Control ◽  
Advantages And Disadvantages

The Laboratory of Transport Technology (Ghent University) converted a GM/Crusader V-8 engine for hydrogen use. The engine is intended for the propulsion of a midsize hydrogen city bus for public demonstration. For a complete control of the combustion process and to increase the resistance to backfire (explosion of the air–fuel mixture in the intake manifold), a sequential timed multipoint injection of hydrogen and an electronic management system is chosen. The results as a function of the engine parameters (ignition timing, injection timing and duration, injection pressure) are given. Special focus is given to topics related to the use of hydrogen as a fuel: ignition characteristics (importance of electrode distance), quality of the lubricating oil (crankcase gases with high contents of hydrogen), oxygen sensors (very lean operating conditions), and noise reduction (configuration and length of intake pipes). The advantages and disadvantages of a power regulation only by the air-to-fuel ratio (as for diesel engines) against a throttle regulation (normal gasoline or gas regulation) are examined. Finally, the goals of the development of the engine are reached: power output of 90 kW, torque of 300 Nm, extremely low emission levels, and backfire-safe operation.

Residual Gas Fraction Measurement in Spark Ignition Engines

2005 ◽  
Author(s):  
P. Giansetti ◽  
P. Higelin ◽  
Y. Chamaillard ◽  
A. Charlet
Keyword(s):  
Spark Ignition ◽  
Spark Ignition Engines ◽  
Residual Gas Fraction ◽  
Residual Gas ◽  
Fraction Measurement

A Model for Residual Gas Fraction Prediction in Spark Ignition Engines

2002 ◽  
Author(s):  
P. Giansetti ◽  
C. Perrier ◽  
P. Higelin ◽  
Y. Chamaillard ◽  
A. Charlet ◽  
...  
Keyword(s):  
Spark Ignition ◽  
Spark Ignition Engines ◽  
Residual Gas Fraction ◽  
Residual Gas

Residual Gas Fraction Estimation for Model-Based Variable Valve Timing and Spark Advance Control

2004 ◽  
Author(s):  
Nicolo` Cavina ◽  
Fabrizio Ponti ◽  
Carlo Siviero ◽  
Rosanna Suglia
Keyword(s):  
Direct Injection ◽  
Management Strategies ◽  
Combustion Process ◽  
Gasoline Direct Injection ◽  
Variable Valve Timing ◽  
Valve Timing ◽  
Residual Gas Fraction ◽  
Residual Gas ◽  
Variable Valve ◽  
Exhaust Valves

As it is well known, the combustion process in Spark Ignition (SI) engines is strongly affected by the quality and quantity of the fluid within the cylinder at Intake Valve Closing (IVC). Residual gas affects the engine combustion processes (and therefore emissions and performance) through its influence on charge mass, temperature and dilution. Moreover, in Gasoline Direct Injection (GDI) engines, the amount of oxygen in the residual gas may be significant if the engine is operated in stratified charge mode (low loads and speeds), while almost no oxygen may be found in the residual gas during homogeneous-charge operation. In this paper, different approaches to residual gas fraction estimation are analyzed and compared. The main objective is to obtain a simple and reliable model also in presence of Variable Valve Timing (VVT, both on intake and exhaust valves) and External Gas Recirculation (EGR) systems, that could be used to control combustion duration and position. In fact, the two main contributions to residual gas fraction (backflow of the burned gas during the valve overlap period, and amount of gas trapped within the cylinder) are strongly affected by intake and exhaust valves timing, and EGR flow should be taken into account in order to determine the total exhaust gas mass within the cylinder at IVC. Therefore, estimation of residual gas mass and composition is crucial for designing VVT and EGR management strategies, integrated with optimal control of Spark Advance (and therefore of the combustion process). Experimental data have been acquired on a 3.2 liter V6 GDI engine, equipped with intake and exhaust VVT systems. Tests were performed throughout the engine operating range for different combinations of intake and exhaust valve timings, while varying EGR flow.

MODERN EQUIPMENT FOR DETERMINING TRACTOR-SPEED PROPERTIES OF THE VEHICLE: CHARACTERISTICS’ ANALYSIS IN LABORATORY CONDITIONS

2019 ◽  
Vol 16 (3) ◽  
pp. 276-289
Author(s):  
N. V. Savenkov ◽  
V. V. Ponyakin ◽  
S. A. Chekulaev ◽  
V. V. Butenko
Keyword(s):  
Environmental Performance ◽  
Operating Conditions ◽  
Special Role ◽  
Development Stages ◽  
Advantages And Disadvantages ◽  
Force Transfer ◽  
Characteristics Analysis ◽  
And Performance ◽  
Loading Devices ◽  
Structural Solutions

Introduction. At present, stands with running drums are widely used for various types of tests. Power stands play a special role. Such stands take the mechanical power from the driving wheels of the car. This simulates the process of movement of the vehicle under operating conditions. Such equipment has various designs, principles of operation and performance. It is also used in tests that are different by purpose, development stages and types: research, control, certification, etc. Therefore, it is necessary in order to determine the traction-speed, fuel-efficient and environmental performance characteristics.Materials and methods. The paper provides the overview of the power stands with running drums, which are widespread on the domestic market. The authors carried out the analysis of the main structural solutions: schemes of force transfer between the wheel and the drum; types of loading devices; transmission layout schemes and features of the control and measuring complex. The authors also considered corresponding advantages and disadvantages, recommended spheres of application, demonstrated parameters and characteristics of the units’ workflow, presented components and equipment.Discussion and conclusions. The authors critically evaluate existing models of stands with running drums. Such information is useful for choosing serial models of stands and for developing technical tasks for designing or upgrading the equipment.

scholarly journals Tagasaste, leucaena and paulownia: three industrial crops for energy and hemicelluloses production

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Alberto Palma ◽  
Javier Mauricio Loaiza ◽  
Manuel J. Díaz ◽  
Juan Carlos García ◽  
Inmaculada Giráldez ◽  
...  
Keyword(s):  
Activation Energy ◽  
Acid Hydrolysis ◽  
Energy Production ◽  
Combustion Process ◽  
Operating Conditions ◽  
Raw Material ◽  
Energy Of Combustion ◽  
Increasing Temperature ◽  
Hydrolysis Of ◽  
Chamaecytisus Proliferus

Abstract Background Burning fast-growing trees for energy production can be an effective alternative to coal combustion. Thus, lignocellulosic material, which can be used to obtain chemicals with a high added value, is highly abundant, easily renewed and usually inexpensive. In this work, hemicellulose extraction by acid hydrolysis of plant biomass from three different crops (Chamaecytisus proliferus, Leucaena diversifolia and Paulownia trihybrid) was modelled and the resulting solid residues were used for energy production. Results The influence of the nature of the lignocellulosic raw material and the operating conditions used to extract the hemicellulose fraction on the heat capacity and activation energy of the subsequent combustion process was examined. The heat power and the activation energy of the combustion process were found to depend markedly on the hemicellulose content of the raw material. Thus, a low content in hemicelluloses resulted in a lower increased energy yield after acid hydrolysis stage. The process was also influenced by the operating conditions of the acid hydrolysis treatment, which increased the gross calorific value (GCV) of the solid residue by 0.6–9.7% relative to the starting material. In addition, the activation energy of combustion of the acid hydrolysis residues from Chamaecytisus proliferus (Tagasaste) and Paulownia trihybrid (Paulownia) was considerably lower than that for the starting materials, the difference increasing with increasing degree of conversion as well as with increasing temperature and acid concentration in the acid hydrolysis. The activation energy of combustion of the solid residues from acid hydrolysis of tagasaste and paulownia decreased markedly with increasing degree of conversion, and also with increasing temperature and acid concentration in the acid hydrolysis treatment. No similar trend was observed in Leucaena diversifolia (Leucaena) owing to its low content in hemicelluloses. Conclusions Acid hydrolysis of tagasaste, leucaena and paulownia provided a valorizable liquor containing a large amount of hemicelluloses and a solid residue with an increased heat power amenable to efficient valorization by combustion. There are many potential applications of the hemicelluloses-rich and lignin-rich fraction, for example as multi-components of bio-based feedstocks for 3D printing, for energy and other value-added chemicals.

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