scholarly journals Investigation into the Relationship between Super-Knock and Misfires in an SI GDI Engine

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2099
Author(s):  
Jian Gao ◽  
Anren Yao ◽  
Yeyi Zhang ◽  
Guofan Qu ◽  
Chunde Yao ◽  
...  
Keyword(s):  
Pressure Fluctuation ◽  
Direct Injection ◽  
Exhaust Valve ◽  
Gasoline Direct Injection ◽  
Exhaust Pipe ◽  
Pressure Transducers ◽  
Spark Plug ◽  
Si Engines ◽  
Gdi Engine ◽  
The Relationship

The super-knock poses new challenges for further increasing the power density of spark ignition (SI) engines. The critical factors and mechanism connecting regarding the occurrence of super-knock are still unclear. Misfire is a common phenomenon in SI engines that the mixture in cylinder is not ignited normally, which is often caused by spark plug failure. However, the effect of misfire on engine combustion has not been paid enough attention to, particularly regarding connection to super-knock. The paper presents the results of experimental investigation into the relationship between super-knock and misfires at low speed and full load conditions. In this work, a boosted gasoline direct injection (GDI) engine with an exhaust manifold integrated in the cylinder head was employed. Four piezoelectric pressure transducers were used to acquire the data of a pressure trace in cylinder. The spark plugs of four cylinders were controlled manually, of which the ignition system could be cut off as demanded. In particular, a piezoelectric pressure transducer was installed at the exhaust pipe before the turbocharger to capture the pressure traces in the exhaust pipe. The results illustrated that misfires in one cylinder would cause super-knock in the other cylinders as well as the cylinder of itself. After one cylinder misfired, the unburned mixture would burn in the exhaust pipe to produce oscillating waves. The abnormal pressure fluctuation in the exhaust pipe was strongly correlated with the occurrence of super-knock. The sharper the pressure fluctuation, the greater the intensity of knock in the power cylinder. The cylinder whose exhaust valve overlapped with the exhaust valve of the misfired cylinder was prone to super-knock.

Combustion Ionization for Detection of Misfire, Knock, and Sporadic Preignition in a Gasoline Direct Injection Engine

2019 ◽  
Vol 141 (11) ◽  
Author(s):  
Samuel Ayad ◽  
Swapnil Sharma ◽  
Rohan Verma ◽  
Naeim Henein
Keyword(s):  
Pressure Transducer ◽  
Direct Injection ◽  
Operating Conditions ◽  
Gasoline Direct Injection ◽  
Ion Current ◽  
Fuel Injector ◽  
Direct Injection Engine ◽  
Gasoline Direct Injection Engine ◽  
Spark Plug ◽  
Knock Sensor

Detection of combustion-related phenomena such as misfire, knock, and sporadic preignition is very important for the development of electronic controls needed for the gasoline direct injection engines to meet the production goals in power, fuel economy, and low emissions. This paper applies several types of combustion ionization sensors, and a pressure transducer that directly senses the in-cylinder combustion, and the knock sensor which is an accelerometer that detects the impact of combustion on engine structure vibration. Experimental investigations were conducted on a turbocharged four-cylinder gasoline direct injection engine under operating conditions that produce the above phenomena. One of the cylinders is instrumented with a piezo quartz pressure transducer, MSFI (multi-sensing fuel injector), a stand-alone ion current probe, and a spark plug applied to act as an ion current sensor. A comparison is made between the capabilities of the pressure transducer, ion current sensors, and the knock sensor in detecting the above phenomena. The signals from in-cylinder combustion sensors give more accurate information about combustion than the knock sensor. As far as the feasibility and cost of their application in production vehicles, the spark plug sensor and MSFI appear to be the most favorable, followed by the stand-alone mounted sensor which is an addition to the engine.

The Effects of Injection Timing and Injected Fuel Mass on Local Charge Conditions and Emissions for Gasoline Direct Injection Engines

2017 ◽  
Author(s):  
Doohyun Kim ◽  
Angela Violi ◽  
André Boehman
Keyword(s):  
Combustion Chamber ◽  
Direct Injection ◽  
Gasoline Direct Injection ◽  
Injection Timing ◽  
Charge Composition ◽  
Gaseous Species ◽  
Fuel Mass ◽  
Soot Precursors ◽  
Gdi Engine ◽  
Fuel Mixing

Increased Particulate Matter (PM) emissions from Gasoline Direct Injection (GDI) engines compared to conventional Port Fuel Injection (PFI) engines have been raising concerns because of the PM’s detrimental health effects and the stringent emissions regulations. One of the widely accepted hypotheses is that local rich pockets inside the combustion chamber are the primary reason for the increased PM emissions. In this paper, we investigate the effects of injection strategies on the charge composition and local thermodynamic conditions of a light duty GDI engine, and determine their impact on PM emissions. The operation of a 1.6L GDI engine is simulated using a 3-D Computational Fluid Dynamics (CFD) code. Combustion characteristics of a 3-component gasoline surrogate (n-heptane/iso-octane/toluene) are analyzed and the effects of injection timing (300° vs 240° vs 180° BTDC) and injected fuel mass (globally stoichiometric vs fuel rich) are explored at 2000 rpm, 9.5 bar BMEP condition, focusing on the homogeneity of the charge and the formation of the gaseous species that are soot precursors. The results indicate that when the physical time for air/fuel mixing is not long enough, fuel-rich pockets are present until combustion occurs, where high concentrations of soot precursors are found, such as acetylene and pyrene. In addition, simulation results indicate that the location of wetted surface as well as the in-cylinder flow structure induced by the fuel jet hitting the piston bowl is significantly influenced by varying the injection timing, which affects subsequent air/fuel mixing. When the injected fuel mass is increased, the equivalence ratio distribution inside the combustion chamber shifts toward fuel-rich side, generating more mixtures with Φ > 1.5, where formation of acetylene and pyrene are favored.

Idle Speed Control for GDI Engines with Interval Time-Delay

2012 ◽  
Vol 588-589 ◽  
pp. 1598-1601 ◽  
Author(s):  
Xue Jun Li ◽  
Wei Hong ◽  
Yan Su
Keyword(s):  
Control System ◽  
Direct Injection ◽  
Speed Control ◽  
Gasoline Direct Injection ◽  
Idle Speed ◽  
Idle Speed Control ◽  
Interval Delay ◽  
Gdi Engine ◽  
The Stability ◽  
Gdi Engines

The gasoline direct injection (GDI) engine is a highly non-linear and a delayed system. The engine modle with time-delays is derived. The delays consist of an intake to torque production state delay and a network -induced interval delay. Base on the Liapunov-Krasovskii function, the criterion of interval delay control system is proposed, which ensure the idle speed control system is stability as well as robust. The simulation results show that the H∞ control has good robustness,which improves the stability of the idle speed of the GDI engine.

Effect of Conical Spray and Multi-Hole Spray on Gasoline Engine Mixture Formation and Combustion Performance Based on Different Injection Strategies

2020 ◽  
Vol 143 (6) ◽  
Author(s):  
Shengli Wei ◽  
Zhiqing Yu ◽  
Zhilei Song ◽  
Fan Yang ◽  
Chengcheng Wu
Keyword(s):  
Gasoline Engine ◽  
Direct Injection ◽  
Mixture Distribution ◽  
Gasoline Direct Injection ◽  
Injection Timing ◽  
Mixture Formation ◽  
Injection Strategy ◽  
Gdi Engine ◽  
The Difference ◽  
Injection Strategies

Abstract This article presents a numerical investigation carried out to determine the effects of second and third injection timing on combustion characteristics and mixture formation of a gasoline direct injection (GDI) engine by comparing conical spray against multihole spray. The results showed that at the engine 80% full load of 2000 r/min, the difference in mixture distribution between the two sprays was obvious with double and triple injection strategies. With the second injection timing from 140 deg CA delay to 170 deg CA, the in-cylinder pressure, the in-cylinder temperature, and the heat release rate of the conical spray increased by 20.8%, 9.8%, and 30.7% and that of the multihole spray decreased by 30.7%, 13.6%, and 37.8%. The delay of the injection time reduced the performance of the engine with the multihole spray, and the performance of the multihole spray was obviously in the simulation of the triple injection strategy. However, for the conical spray, the application of the triple injection strategy increased the temperature and the pressure compared with the double injection strategy.

Simulation Research on the Spray and Formation of Mixture of Gasoline Direct Injection Engine

2013 ◽  
Vol 448-453 ◽  
pp. 3440-3444
Author(s):  
Bo Yu Chen ◽  
Ai Min Du ◽  
Zhi Jun Xu
Keyword(s):  
Computational Model ◽  
Cfd Simulation ◽  
Direct Injection ◽  
Simulation Software ◽  
Gasoline Direct Injection ◽  
Simulation Research ◽  
Gasoline Direct Injection Engine ◽  
Calculation Results ◽  
Gdi Engine ◽  
Load Conditions

A computational model of a GDI engine is established by 3D CFD simulation software. A simulation on the formation of mixture of the engine under 1500r/min, full load conditions are carried out. The calculation results provide a reference for the optimizing of the engine.

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.

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