A Study of Quasi-Homogeneous Lean Burn Gasoline Engine Performance Based on the Numerical Simulation

2013 ◽  
Vol 278-280 ◽  
pp. 174-177
Author(s):  
Wen Zhang ◽  
Zhi Jun Li ◽  
Chun Qia Liu ◽  
Ming Li ◽  
Qing Chang
Keyword(s):  
Gasoline Engine ◽  
Engine Performance ◽  
Emission Characteristic ◽  
Dimensional Model ◽  
Lean Burn ◽  
One Dimensional ◽  
Lean Combustion ◽  
Combustion Limit ◽  
The Relationship ◽  
Co Emission

A CA3GA2 lean combustion gasoline engine one dimensional model was built by AVL BOOST software. The relationship between air-to-fuel ratio (A/F) and emission characteristic and fuel economy was simulated. Simulation shows that: (1) CO emission decreases as the A/F ratio increases; (2) HC emission reaches its lowest point at A/F=16~18; (3) NOX emission reaches its highest point at A/F=16~18; (4) the engine lean combustion limit is A/F=22, the brake specific fuel consumption (BSFC) decreases as the A/F ratio increases within the lean combustion limit.

The Research of Lean Combustion Characteristic of Compound Injection System of Direct Injection Engine

2014 ◽  
Vol 532 ◽  
pp. 362-366 ◽  
Author(s):  
Jiang Feng Mou ◽  
Rui Qing Chen ◽  
Yi Wei Lu
Keyword(s):  
Gasoline Engine ◽  
Direct Injection ◽  
Injection System ◽  
Intake Manifold ◽  
Combustion Characteristic ◽  
Injection Timing ◽  
Mixed Gas ◽  
Lean Burn ◽  
Direct Injection Engine ◽  
Lean Combustion

This paper studies the lean burn limit characteristic of the compound injection system of the direct-injection gasoline engine. The low pressure nozzle on the intake manifold can achieve quality homogeneous lean mixture, and the direct injection in the cylinder can realized the dense mixture gas near the spark plug. By adjusting the two injection timing and injection quantity, and a strong intake tumble flow with special shaped combustion chamber, it can produces the reverse tumble to form different hierarchical levels of mixed gas in the cylinder. Experimental results show: the compound combustion system to the original direct-injection engine lean burn limit raise 1.8-2.5 AFR unit.

Economy and emission characteristics of the optimal dilution strategy in lean combustion based on GDI gasoline engine equipped with prechamber

2021 ◽  
Vol 13 (12) ◽  
pp. 168781402110381
Author(s):  
Li Wang ◽  
Zhaoming Huang ◽  
Wang Tao ◽  
Kai Shen ◽  
Weiguo Chen
Keyword(s):  
Fuel Economy ◽  
Gasoline Engine ◽  
Direct Injection ◽  
Engine Performance ◽  
Gasoline Direct Injection ◽  
Dilution Ratio ◽  
Lean Combustion ◽  
Excess Air ◽  
Combustion Phase ◽  
Hc Emissions

EGR and excess-air dilution have been investigated in a 1.5 L four cylinders gasoline direct injection (GDI) turbocharged engine equipped with prechamber. The influences of the two different dilution technologies on the engine performance are explored. The results show that at 2400 rpm and 12 bar, EGR dilution can adopt more aggressive ignition advanced angle to achieve optimal combustion phasing. However, excess-air dilution has greater fuel economy than that of EGR dilution owing to larger in-cylinder polytropic exponent. As for prechamber, when dilution ratio is greater than 37.1%, the combustion phase is advanced, resulting in fuel economy improving. Meanwhile, only when the dilution ratio is under 36.2%, the HC emissions of excess-air dilution are lower than the original engine. With the increase of dilution ratio, the CO emissions decrease continuously. The NOX emissions of both dilution technologies are 11% of those of the original engine. Excess-air dilution has better fuel economy and very low CO emissions. EGR dilution can effectively reduce NOX emissions, but increase HC emissions. Compared with spark plug ignition, the pre chamber ignition has lower HC, CO emissions, and higher NO emissions. At part load, the pre-chamber ignition reduces NOX emissions to 49 ppm.

scholarly journals Land subsidence and hydrodynamic compaction of sedimentary basins

1998 ◽  
Vol 2 (2/3) ◽  
pp. 159-171 ◽  
Author(s):  
H. Kooi ◽  
J. J. de Vries
Keyword(s):  
Response Time ◽  
Land Subsidence ◽  
Sedimentary Basins ◽  
Sediment Loading ◽  
Dimensional Model ◽  
One Dimensional ◽  
Model Equations ◽  
Sediment Layers ◽  
The Relationship

Abstract. A one-dimensional model is used to investigate the relationship between land subsidence and compaction of basin sediments in response to sediment loading. Analysis of the model equations and numerical experiments demonstrate quasi-linear systems behaviour and show that rates of land subsidence due to compaction: (i) can attain a significant fraction (>40%) of the long-term sedimentation rate; (ii) are hydrodynamically delayed with respect to sediment loading. The delay is controlled by a compaction response time τc that can reach values of 10-5-107 yr for thick shale sequences. Both the behaviour of single sediment layers and multiple-layer systems are analysed. Subsequently the model is applied to the coastal area of the Netherlands to illustrate that lateral variability in compaction-derived land subsidence in sedimentary basins largely reflects the spatial variability in both sediment loading and compaction response time. Typical rates of compaction-derived subsidence predicted by the model are of the order of 0.1 mm/yr but may reach values in excess of 1 mm/yr under favourable conditions.

Experimental and Theoretical Study of Injection Timing on Performance and Exhaust Emissions in a Port-Injected Gasoline Engine

2006 ◽  
Author(s):  
E. Movahednejad ◽  
F. Ommi ◽  
M. Hosseinalipour ◽  
O. Samimi
Keyword(s):  
Gasoline Engine ◽  
Fuel Injection ◽  
Engine Performance ◽  
Fuel Mixture ◽  
Exhaust Emissions ◽  
Operating Conditions ◽  
Exhaust Emission ◽  
Injection Timing ◽  
Intake Port ◽  
One Dimensional

For spark ignition engines, the fuel-air mixture preparation process is known to have a significant influence on engine performance and exhaust emissions. In this paper, an experimental study is made to characterize the spray characteristics of an injector with multi-disc nozzle used in the engine. The distributions of the droplet size and velocity and volume flux were characterized by a PDA system. Also a model of a 4 cylinder multi-point fuel injection engine was prepared using a fluid dynamics code. By this code one-dimensional, unsteady, multiphase flow in the intake port has been modeled to study the mixture formation process in the intake port. Also, one-dimensional air flow and wall fuel film flow and a two-dimensional fuel droplet flow have been modeled, including the effects of in-cylinder mixture back flows into the port. The accuracy of model was verified using experimental results of the engine testing showing good agreement between the model and the real engine. As a result, predictions are obtained that provide a detailed picture of the air-fuel mixture properties along the intake port. A comparison was made on engine performance and exhaust emission in different fuel injection timing for 2600 rpm and different loads. According to the present investigation, optimum injection timing for different engine operating conditions was found.

scholarly journals One-Dimensional Simulation Using Port Water Injection for a Spark Ignition Engine

2018 ◽  
Vol 15 (4) ◽  
pp. 5803-5814 ◽  
Author(s):  
C. H. Ling ◽  
M. A. Abas
Keyword(s):  
Fuel Consumption ◽  
Gasoline Engine ◽  
Nox Reduction ◽  
Water Injection ◽  
Engine Performance ◽  
Simulation Software ◽  
Spark Ignition Engine ◽  
Baseline Model ◽  
One Dimensional ◽  
Model Water

Water injection is a promising solution to reduce fuel consumption while improving the performance of a turbocharged gasoline engine. One-dimensional (1D) engine simulation software, AVL BOOST is rarely used to model water injection. Therefore, this study is aimed to demonstrate the detailed port water injection modelling via AVL BOOST. A four-cylinder turbocharged gasoline engine was developed in AVL BOOST based on the specification of the engine test rig and verified to be used as the baseline model. The port water injection modelling was then added to the baseline model. Water to fuel mass ratios of 0.05, 0.10, 0.15, 0.2 and 0.25 were chosen as the variables to investigate the effect of water injection on the engine performance. The results showed that maximum engine torque and IMEP increased by 10.80% and 8.65%, respectively at 3000 rpm. The water injection also reduced the in-cylinder pressure at the end of the compression stroke, reducing the compression work and improving efficiency. The reduction of combustion temperature also indicates potential for NOx reduction. The lower exhaust temperature can reduce the use of fuel enrichment which consequently reduces the fuel consumption. Conclusively, the water injection model can predict the engine performance parameters accurately.

scholarly journals The two-spin model of a tracking chamber: a phase-space perspective

2021 ◽  
Author(s):  
Luigi Barletti
Keyword(s):  
Phase Space ◽  
Spin Model ◽  
Space Representation ◽  
Dimensional Model ◽  
Wigner Matrix ◽  
One Dimensional ◽  
Classical Localization ◽  
Relationship Of ◽  
The Relationship ◽  
Phase Space Representation

AbstractWe study the dynamics of classical localization in a simple, one-dimensional model of a tracking chamber. The emitted particle is represented by a superposition of Gaussian wave packets moving in opposite directions, and the detectors are two spins in fixed, opposite positions with respect to the central emitter. At variance with other similar studies, we give here a phase-space representation of the dynamics in terms of the Wigner matrix of the system. This allows a better visualization of the phenomenon and helps in its interpretation. In particular, we discuss the relationship of the localization process with the properties of entanglement possessed by the system.

Numerical Study of the Combustion Characteristics of a Diesel Micro Pilot Ignited DI Gasoline Engine With Turbocharging and Cooled EGR

2013 ◽  
Author(s):  
Yuhua (York) Zhu ◽  
Nameer Salman ◽  
Kevin Freeman ◽  
Ronald Reese ◽  
Zihan Wang ◽  
...  
Keyword(s):  
Gasoline Engine ◽  
Numerical Study ◽  
Direct Injection ◽  
Engine Performance ◽  
Combustion Characteristics ◽  
Significant Fraction ◽  
Combustion Stability ◽  
Ignition Source ◽  
Lean Burn ◽  
Load Range

Advanced technologies combining turbocharging, downsizing, direct injection, and cooled EGR are being intensively investigated in order to significantly improve the fuel economy of spark-ignition (SI) gasoline engines. To avoid the occurrence of knock and to improve the thermal efficiency, a significant fraction of EGR is often used. Due to the significant fraction of EGR, the ignition source needs to be enhanced to ensure high combustion stability. In addition to advanced spark-based solutions, diesel micro-pilot (DMP) technology has been proposed in recent years where the diesel fuel replaces the spark-plug as the ignition source. This paper studies the combustion characteristics of a diesel micro pilot ignited gasoline engine, employing direct injection of gasoline and diesel as well as turbocharging and cooled EGR. A multi-dimensional CFD code with a chemical kinetic calculation capability was extensively validated across the engine speed and load range in a previous study [1]. This paper explores the influence of a number of parameters on DMP combustion behavior, including: diesel pilot mass fraction, start of injection (SOI), DMP injection strategy, as well as EGR rate, air/fuel ratio, and DI gasoline/air mixture inhomogeneity. Besides, the comparison of DMP ignited combustion with traditional spark ignited combustion is also made in terms of EGR tolerance, lean burn limit, and DI gasoline air mixture inhomogeneity. Finally, numerical simulations aimed at optimizing both gasoline and diesel injection parameters, as well as EGR rate in order to enhance the engine performance in the DMP combustion mode, are discussed.

Study on Fuel Economy and Exhaust Emission of Lean-Burn PFI Engines

2011 ◽  
Vol 130-134 ◽  
pp. 1749-1752
Author(s):  
Xing Bo Yuan ◽  
Zhi Jun Li ◽  
Shao Shu Chen ◽  
Ying Zhang
Keyword(s):  
Fuel Economy ◽  
Engine Speed ◽  
Gasoline Engine ◽  
Exhaust Emission ◽  
Lean Burn ◽  
Emission Level ◽  
Light Load ◽  
Advanced Technologies ◽  
Load Increase ◽  
Co Emission

Lean-burn engines operate at a very lean air-to-fuel (A/F) ratio under light-load and part-load regions, in order to analyze the effect of engine speed and load on the BSFC (Break Specific Fuel Consumption) and exhaust emission of Lean-burn engine, an experimental research was conducted on a 4 cylinder lean-burn gasoline engine using different A/F ratios. The results show that the CO emission level decrease significantly, HC emission level becomes lower at the same A/F ratio, while the NOx emission increases, hence, advanced technologies are needed to carry out the NOx storage and purge operations in the lean-burn engines. Additionally, the experiment also reveals that the BSFC becomes lower as the engine speed and load increase.

Research on NOx Emission Aftertreatment of Lean Burn Gasoline Engine Using Adsorber Reduction Catalyst

2007 ◽  
Author(s):  
Zhengmao Ye ◽  
Zhijun Li ◽  
Habib Mohamadian
Keyword(s):  
Engine Speed ◽  
Gasoline Engine ◽  
Operating Time ◽  
Nox Emission ◽  
Emission Characteristic ◽  
Lean Burn ◽  
Gasoline Engines ◽  
Wide Range ◽  
Nox Adsorber ◽  
Novel Catalyst

A novel catalyst converter system has been developed for NOx emission aftertreatment of lean burn gasoline engines. The goal is to investigate its impact on emission characteristic and Break Specific Fuel Consumption (BSFC) across a wide range of engine speed and load operating regions, subject to several arrangement schemes for this catalyst converter. It has been indicated from experimental results that the upstream placement of TWC (Three Way Catalyst) ahead of the NOx Adsorber Catalyst is the best solution, which gives rise to the highest converting efficiency to reduce the NOx emission level of the lean burn gasoline engine. The effects of engine speed on exhaust emissions and BSFC are also reflected by operating time of lean mode and rich mode as well as the time ratio between the two using adsorber-reduction catalyst converters. Engine load is in fact the major factor in affecting exhaust characteristics and BSFC of lean burn engines.

Sign in / Sign up

Export Citation Format

Share Document