Contribution of Fuel Transport Lag and Statistical Perturbation in Combustion to Oscillation of SI Engine Speed at Idle

1987 ◽  
Author(s):  
H. Ando ◽  
M. Motomochi
Keyword(s):  
Engine Speed ◽  
Si Engine ◽  
Statistical Perturbation

scholarly journals Efficiency characteristics of a new quasi-constant volume combustion spark ignition engine

2013 ◽  
Vol 17 (1) ◽  
pp. 119-133 ◽  
Author(s):  
Jovan Doric ◽  
Ivan Klinar
Keyword(s):  
Engine Speed ◽  
Combustion Process ◽  
Spark Ignition ◽  
Constant Volume ◽  
Spark Ignition Engine ◽  
Si Engine ◽  
Piston Mechanism ◽  
Si Engines ◽  
Ic Engines ◽  
Engine Concept

A zero dimensional model has been used to investigate the combustion performance of a four cylinder petrol engine with unconventional piston motion. The main feature of this new spark ignition (SI) engine concept is the realization of quasi-constant volume (QCV) during combustion process. Presented mechanism is designed to obtain a specific motion law which provides better fuel consumption of internal combustion (IC) engines. These advantages over standard engine are achieved through synthesis of unconventional piston mechanism. The numerical calculation was performed for several cases of different piston mechanism parameters, compression ratio and engine speed. Calculated efficiency and power diagrams are plotted and compared with performance of ordinary SI engine. The results show that combustion during quasi-constant volume has significant impact on improvement of efficiency. The main aim of this paper is to find a proper kinematics parameter of unconventional piston mechanism for most efficient heat addition in SI engines.

Experimental Investigation of Pressure Wave Supercharging for SI Engine

2004 ◽  
Author(s):  
Takashi Suzuki ◽  
Yasufumi Oguri ◽  
Keisuke Uchida ◽  
Masatake Yoshida
Keyword(s):  
Experimental Investigation ◽  
Working Conditions ◽  
Pressure Wave ◽  
Engine Speed ◽  
Exhaust Gas ◽  
Rotor Speed ◽  
Si Engine ◽  
Compression Efficiency ◽  
Speed Range ◽  
Engine Rotor

The objective of this paper is to find experimentally the suitable working conditions of a pressure wave supercharger (PWS) for SI engine. A belt-driven CVT was installed in order to drive the rotor of PWS to the appropriate speed regardless of engine speed. The maximum BMEP was achieved by changing speed of the PWS rotor at constant engine speed and throttle open ratio. From the experiment, the appropriate rotor speeds which led to maximum BMEP at every engine speed and throttle open ratio were achieved. The results showed that two power peaks existed during the range of the tested rotor speed. Since the drop in BMEP between these two power peaks was relatively small, the rotor speed range between these points was defined as effective rotor speed. At engine speed of 2000–4000rpm, the effective rotor speed was found at the engine-rotor ratio of 2.5. In addition, the maximum compression efficiency of PWS was 75% at engine speed of 3000rpm and the exhaust gas pressure reduced to the same level of commonly used turbochargers at all engine speed. Furthermore, results of the transient experiment showed that PWS had as good response as the small turbocharger, which was optimized for the tested engine.

scholarly journals Optimization of 2‑Stage Turbocharged Gas SI Engine Under Steady State Operation

2017 ◽  
Vol 15 (2) ◽  
pp. 9-36
Author(s):  
Oldřich Vítek ◽  
Jan Macek ◽  
Jiří Klíma ◽  
Martin Vacek
Keyword(s):  
Steady State ◽  
Control Algorithm ◽  
Engine Speed ◽  
Boost Pressure ◽  
Si Engine ◽  
Engine Model ◽  
Steady State Operation ◽  
Swallowing Capacity ◽  
The Right ◽  
Different Levels

Abstract The proposed paper deals with an optimization of a highly-turbocharged large-bore gas SI engine. Only steady state operation (constant engine speed and load) is considered. The paper is mainly focused on theoretical potential of 2-stage turbocharging concept in terms of performance and limitation. The results are obtained by means of simulation using complex 0-D/ 1-D engine model including the control algorithm. Different mixture composition concepts are considered to satisfy different levels of NOx limit - fresh air mixed with external cooled EGR is supposed to be the right approach while optimal EGR level is to be found. Considering EGR circuit, 5 different layouts are tested to select the best design. As the engine control is relatively complex (2-sage turbocharger group, external EGR, compressor blow-by, controlled air excess), 5 different control means of boost pressure were considered. Each variant based on above mentioned options is optimized in terms of compressor/turbine size (swallowing capacity) to obtain the best possible BSFC. The optimal variants are compared and general conclusions are drawn.

scholarly journals EFFECT OF LOWER ETHANOL GASOLINE BLENDS ON PERFORMANCE AND EMISSION CHARACTERISTICS OF THE SINGLE CYLINDER SI ENGINE

2012 ◽  
pp. 266-269
Author(s):  
V. S. KUMBHAR ◽  
D. G. MALI ◽  
P. H. PANDHARE ◽  
R. M. MANE
Keyword(s):  
Fuel Consumption ◽  
Engine Speed ◽  
Automotive Application ◽  
Emission Characteristics ◽  
Effective Pressure ◽  
Si Engine ◽  
Single Cylinder ◽  
Performance And Emission ◽  
Brake Mean Effective Pressure ◽  
Co Emission

Alcohols, basically ethanol is considered as a leading alternative fuel for automotive application because of its ability to reduce the air pollution and cost of the fuel. This paper investigates the effect of lower ethanol gasoline blends (up to 20% by volume) on performance and emission characteristics of the single cylinder four stroke SI engine. Tests were carried out for power, torque, fuel consumption and brake mean effective pressure, while exhaust emissions were analyzed for CO, CO2, and HC by using different ethanol gasoline blends on volume basis at wide open throttle and variable engine speed from 4000 to 8000 rpm. Results were compared with the pure gasoline. It showed that as the ethanol content increases the power, torque, fuel consumption, brake mean effective pressure and CO2 emission while reduces HC and CO emission.

IMEP-Estimation and In-Cylinder Pressure Reconstruction for Multicylinder SI-Engine by Combined Processing of Engine Speed and One Cylinder Pressure

2005 ◽  
Author(s):  
Haris Hamedović ◽  
Franz Raichle ◽  
Jörg Breuninger ◽  
Wolfgang Fischer ◽  
Werner Dieterle ◽  
...  
Keyword(s):  
Engine Speed ◽  
Cylinder Pressure ◽  
Si Engine

A New Physics-Based Misfire Detection Technique for a SI Engine

2013 ◽  
Author(s):  
M. Boudaghi Kh. N. ◽  
M. Shahbakhti ◽  
S. A. Jazayeri
Keyword(s):  
Steady State ◽  
Engine Speed ◽  
New Physics ◽  
New Technique ◽  
Si Engine ◽  
Engine Model ◽  
Compensation Factor ◽  
Wide Range ◽  
Percent Accuracy ◽  
Misfire Detection

Control and detection of misfire is an essential part of on-board diagnosis of modern SI engines. This study proposes a novel model-based technique for misfire detection of a multi-cylinder SI engine. The new technique uses a dynamic engine model to determine mean output power, which is then used to calculate a new parameter for misfire detection. The new parameter directly relates to combustion period and is sensitive to the engine speed fluctuations caused by misfire. The new technique only requires measured engine speed data and it is computationally viable for use in a typical ECU. The new technique is evaluated experimentally on a 4-cylinder 1.6-liter SI engine. Three types of misfires are studied including single, continues, and multiple events. The steady-state and transient experiments were done for a wide range of engine speeds and engine loads, using a vehicle chassis dynamometer and on-road vehicle testing. The validation results show the new technique is capable to detect all the three types of misfire with up to 97 percent accuracy during steady-state conditions. The new technique is augmented with a compensation factor to improve the accuracy of the technique for transient operations. The resulting technique is shown to be capable of detecting misfire during both transient and steady-state engine conditions.

Misfire Detection of Spark Ignition Engines Using a New Technique Based on Mean Output Power

2015 ◽  
Vol 137 (9) ◽  
Author(s):  
M. Boudaghi ◽  
M. Shahbakhti ◽  
S. A. Jazayeri
Keyword(s):  
Steady State ◽  
Output Power ◽  
Engine Speed ◽  
Control Unit ◽  
Spark Ignition ◽  
New Technique ◽  
Si Engine ◽  
Engine Model ◽  
Wide Range ◽  
Misfire Detection

Control and detection of misfire are an essential part of on-board diagnosis (OBD) of modern spark ignition (SI) engines. This study proposes a novel model-based technique for misfire detection for a multicylinder SI engine. The new technique uses a dynamic engine model to determine mean output power, which is then used to calculate a new parameter for misfire detection. The new parameter directly relates to combustion period and is sensitive to engine speed fluctuations caused by misfire. The new technique requires only measured engine speed data and is computationally viable for use in a typical engine control unit (ECU). The new technique is evaluated experimentally on a four-cylinder 1.6-l SI engine. Three types of misfire are studied including single, continuous, and multiple-event. The steady-state and transient experiments were done for a wide range of engine speeds and engine loads, using a vehicle chassis dynamometer and on-road vehicle testing. The validation results show that the new technique is able to detect all three types of misfire with up to 94% accuracy during steady-state conditions. The new technique is augmented with a compensation factor to improve the accuracy of the technique for transient operations. The resulting technique is shown to be capable of detecting misfire during both transient and steady-state engine conditions.

Numerical Simulations of a Hydrogen-Enriched Methane Fueled Spark Ignition Engine

2004 ◽  
Author(s):  
V. Matham ◽  
K. Majmudar ◽  
K. Aung
Keyword(s):  
Numerical Simulations ◽  
Alternative Fuels ◽  
Engine Speed ◽  
Current Model ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Ignition Timing ◽  
Si Engine ◽  
Gaseous Fuels ◽  
Si Engines

The use of alternative fuels such as natural gas (methane) in spark-ignition (SI) engines is beneficial to the environment as it reduces emissions of pollutants such as NOx from these engines with slight penalty on the performance. This paper investigated the use of methane and hydrogen/methane mixtures in an SI engine by numerical simulations. The numerical simulations were based on the models of finite heat release, cylinder heat transfer, pumping losses, and friction losses. Simulations were carried out to evaluate the effects of compression ratio, equivalence ratio, ignition timing, and engine speed on the performance of the SI engine. The results showed that the current model could satisfactorily predict the performance of an SI engine fueled by gaseous fuels.

Energy and Exergy Based Analyses of a Multi-Fuelled SI Engine

2013 ◽  
Author(s):  
M. Z. Haq ◽  
A. Morshed
Keyword(s):  
Alternative Fuels ◽  
Engine Speed ◽  
Burning Velocity ◽  
Spark Ignition Engine ◽  
Si Engine ◽  
Engine Cylinder ◽  
Energy And Exergy ◽  
Si Engines ◽  
Exergy Analyses ◽  
Wiebe Function

The paper presents energy and exergy based analyses of a single cylinder, four-stroke, spark ignition engine fuelled by six different fuels namely iso-octane, methane, hydrogen, methanol, ethanol and n-butanol. Wiebe function is used to predict realistic burn rates. Since the Wiebe function parameters are generally optimized for conventional fuels, the current study modifies them for different alternative fuels using available burning velocity data. Heat losses throughout the cycle have been predicted by empirical correlations. Analyses are carried out to quantify energy and exergy of the premixed fuel-air mixture inside the engine cylinder at various phases of the cycle and some results obtained from the study are validated against data available in literature. Both energy and exergy destructions are found to be dependent on the fuels and engine operating parameters. Results show that at 1000 rpm, about 34–39% of energy contained in the fuel is converted into useful work and this quantity is found to increase with engine speed. Exergies associated with exhaust are found significantly lower than the corresponding energy values for all fuels. The present study highlights the necessity of both energy and exergy analyses to probe and identify the sources of work potential losses in SI engines in various phases of the cycle.

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