Reconstructing Cylinder Pressure of a Spark-Ignition Engine for Heat Transfer and Heat Release Analyses

2004 ◽  
Author(s):  
Pin Zeng ◽  
Robert G. Prucka ◽  
Zoran S. Filipi ◽  
Dennis N. Assanis
Keyword(s):  
Heat Transfer ◽  
Heat Release ◽  
Engine Speed ◽  
Gasoline Engine ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Cylinder Pressure ◽  
Spark Timing ◽  
Heavy Duty Diesel Engine ◽  
Heavy Duty Diesel

This paper proposes a technique for reconstructing the cylinder pressure traces of a spark-ignition engine based on three inputs: spark-timing, speed and load. This method is an extension of previous work for reconstructing cylinder pressure in a heavy-duty diesel engine [1]. The previous study utilized only two inputs for cylinder pressure reconstruction, e.g. engine speed and load, hence implying optimal combustion phasing. The new method adds one more input to allow reconstruction of pressure traces from cycles with combustion phasing altered based on emissions or knock constraints. The method was applied to a 4-cylinder, 2.4-liter DaimlerChrysler gasoline engine. Comparisons between measured and reconstructed cylinder pressure traces demonstrate that the method is applicable over the majority of the gasoline engine operating range. Reconstructed cylinder pressure traces have also been used to carry out engine heat transfer and heat release analyses. Problems associated with the application of this method to gasoline engine are also discussed.

Effects of Different LPG Fuel Systems on Performances of Variable Compression Ratio Single Cylinder Engine

2002 ◽  
Author(s):  
G. H. Choi ◽  
J. H. Kim ◽  
Christian Homeyer
Keyword(s):  
Liquid Phase ◽  
Heat Release ◽  
Compression Ratio ◽  
Power Output ◽  
Alternative Fuels ◽  
Gasoline Engine ◽  
Cylinder Pressure ◽  
Maximum Heat ◽  
Spark Timing ◽  
Test Engine

Since the early 20th century, most ground vehicles are driven with gasoline and diesel. The degradation of the environment affects human on earth unless the quality of the air is improved. One of the alternative fuels, LPG, is potentially capable of lowering vehicular emissions when compared to gasoline or diesel. There is a penalty in power output resulting from the use of LPG because the engine can induce less amount of air with Mixer system comparing with gasoline engine. Currently, the liquid-phase LPG is injected into the intake port of the engine, the fuel vaporizes enroute to the combustion chamber. Therefore, the performance and combustion processes of the tested engine are investigated with different LPG fuel systems. The test engine was developed and named heavy-duty VACRE. The test engine for this work operates 1400rpm with MBT conditions. The major conclusions of the work include; 1) The power output of LPi system with liquid-phase is approximately 17% higher than that of vapor-phase Mixer system due to increases of volumetric efficiency. And the MBT spark timing of LPi system is approximately 25% more advanced than that of Mixer system at λ value 1.0; 2) The LPi system shows both the maximum heat release rate and the cumulative heat release to be approximately 20% higher than the Mixer system; 3) Maximum cylinder pressure decrease with increase of compression ratio and a point of maximum cylinder pressure is delayed with high compression ratio.

Mathematical analysis of spark ignition engine operation via the combination of the first and second laws of thermodynamics

2008 ◽  
Vol 464 (2100) ◽  
pp. 3107-3128 ◽  
Author(s):  
İsmet Sezer ◽  
Atilla Bilgin
Keyword(s):  
Equivalence Ratio ◽  
Engine Speed ◽  
Exergy Analysis ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Second Law ◽  
Operational Parameters ◽  
Engine Operation ◽  
Availability Analysis ◽  
Spark Timing

This study aims at the theoretical exergetic evaluation of spark ignition engine operation. For this purpose, a two-zone quasi-dimensional cycle model was installed, not considering the complex calculation of fluid motions. The cycle simulation consists of compression, combustion and expansion processes. The combustion phase is simulated as a turbulent flame propagation process. Intake and exhaust processes are also computed by a simple approximation method. The results of the model were compared with experimental data to demonstrate the validation of the model. Principles of the second law are applied to the model to perform the exergy (or availability) analysis. In the exergy analysis, the effects of various operational parameters, i.e. fuel–air equivalence ratio, engine speed and spark timing on exergetic terms have been investigated. The results of exergy analysis show that variations of operational parameters examined have considerably affected the exergy transfers, irreversibilities and efficiencies. For instance, an increase in equivalence ratio causes an increase in irreversibilities, while it decreases the first and also the second law efficiencies. The irreversibilities have minimum values for the specified engine speed and optimum spark timing, while the first and second law efficiencies reach a maximum at the same engine speed and optimum spark timing.

Closed Loop, Knock Adaptive Spark Timing Control Based on Cylinder Pressure

1979 ◽  
Vol 101 (1) ◽  
pp. 64-69 ◽  
Author(s):  
R. J. Hosey ◽  
J. D. Powell
Keyword(s):  
Engine Speed ◽  
Closed Loop ◽  
Fuel Efficiency ◽  
Combustion Process ◽  
Spark Ignition Engine ◽  
Cylinder Pressure ◽  
Timing Control ◽  
Spark Timing ◽  
Engine Knock ◽  
Reduction Of Emissions

One of the important inputs to a spark ignition engine which affects nearly all engine outputs is spark advance. Spark advance not only affects fuel efficiency and exhaust emissions but is also a factor in the tendency for detonation or engine knock. Increasing pressure for reduction of emissions and better fuel economy is making effective spark advance control more important. The desire for improved efficiency is complicated by the increased use of low octane, lead-free gasoline which is an influence toward conservative, inefficient engine designs for reduction of engine knock. Conventional spark advance systems control on parameters which are inputs to the combustion process, such as manifold vacuum and engine speed. This paper describes a microprocessor based spark timing controller based on measurements of cylinder pressure history, a parameter which is a result of the combustion process. To feedback element is an experimental piezoelectric pressure transducer of an inexpensive design which would be suitable for mass production. Results are presented showing that this feedback controller is able to control spark advance to 1 percent of optimum even over fuel-air ratio changes of 40 percent. The controller also effectively controls engine knock to levels which are not harmful.

Combustion Characteristics of Spark Ignition Engine Fuelled by LPG

2001 ◽  
Author(s):  
M. S. Shehata
Keyword(s):  
Engine Speed ◽  
Cooling Water ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Maximum Efficiency ◽  
Cylinder Pressure ◽  
Gas Temperature ◽  
Ignition Timing ◽  
Increase With Increase ◽  
Crank Angle

Abstract Experimental studies have been carried out for investigating engine performance parameters, cylinder pressure, emissions and engine thermal balance of spark ignition engine (S.I.E.) using either gasoline or Liquefied Petroleum Gases (LPG) as a fuel at maximum brake torque (MBT) ignition timing. MBT ignition timing for LPG is found to be 2 to 10 degrees crank angle more advance than for gasoline. Maximum cylinder pressure locations for gasoline and LPG are shifted towards top dead center (TDC) with increase engine speed. At low engine speed, maximum cylinder pressure for gasoline fuel is higher than for LPG fuel. At high engine speeds maximum cylinder pressure for LPG is nearly the same as for gasoline. Maximum pressure for ignition timing 35 crank angle (CA) before top dead center (BTDC) is greater than for 45 and 25 CA respectively. Engine produces more brake power with gasoline than with LPG. Engine brake thermal efficiency (ηbth) and volumetric efficiency (ηv) with LPG is less than for gasoline. When S.I.E converted from gasoline to LPG the loss in maximum power is nearly 14% and the loss in maximum efficiency is nearly 8%. UHC and CO concentrations for LPG are nearly one-tenth of that produced by gasoline at the same ignition timing and the same engine speed. For low engine speed exhaust and oil temperatures for gasoline and LPG increase with increase engine speed but for high engine speed exhaust and oil temperature decreases with increase engine speed. For gasoline and LPG cooling water temperature decreases with increase engine speed. Lubricating oil and cooling water temperatures for gasoline and LPG increase with increase ignition timing BTDC but exhaust gas temperature decreases with increase ignition timing. LPG has higher exhausted gas temperature than gasoline but gasoline has higher oil temperature than LPG. At different ignition timing exhaust loss for LPG is greater than for gasoline but cooling water loss for gasoline is greater than for LPG.

Regulated and unregulated emissions from a spark-ignition engine fuelled with low-blend ethanol–gasoline mixtures

2011 ◽  
Vol 226 (4) ◽  
pp. 517-528 ◽  
Author(s):  
F-J Liu ◽  
P Liu ◽  
Z Zhu ◽  
Y-J Wei ◽  
S-H Liu
Keyword(s):  
Engine Speed ◽  
Gasoline Engine ◽  
Spark Ignition ◽  
Operating Conditions ◽  
Spark Ignition Engine ◽  
Exhaust Temperature ◽  
Fuel Blends ◽  
Before And After ◽  
Unregulated Emissions ◽  
Ethanol Fraction

The effects of ethanol addition to gasoline on the exhaust emissions (including regulated and unregulated emissions) and the conversion efficiencies of the three-way catalyst (TWC) were investigated in a three-cylinder spark-ignition (SI) gasoline engine. Three typical fuel blends – commercial 93# (Research Octane Number) gasoline (E0), E10, and E20 (with 0 per cent, 10 per cent, and 20 per cent ethanol in the blends by volume) – were used in the experiment. Unregulated emissions were measured by gas chromatography with a pulsed discharge helium ionization detector. Experimental results show that the regulated emissions of hydrocarbon, carbon monoxide, and nitrogen oxides decreased before and after the TWC with the increase of ethanol fraction in the fuel blends. However, the unregulated emissions of ethanol, acetaldehyde, and formaldehyde increased with the increase of ethanol fraction and decreased with increased engine speed and/or torque. Ethanol emission was not detected when fuelled with gasoline (E0). Ethanol emission was intensively influenced by the exhaust temperature and disappeared when the exhaust temperature was higher than 900 K for E10 and E20 operation. Acetaldehyde emission definitely comes from the oxidation of ethanol; the engine speed and load have opposite effects on acetaldehyde emission. Both ethanol and acetaldehyde can be converted effectively by the TWC. More formaldehyde was emitted at higher engine speed and lower load operating conditions.

Multiple Combustion Stages Inside a Heavy-Duty Diesel Engine Retrofitted to Natural-Gas Spark-Ignition Operation

2020 ◽  
Vol 142 (2) ◽  
Author(s):  
Jinlong Liu ◽  
Cosmin Emil Dumitrescu
Keyword(s):  
Natural Gas ◽  
Heat Release ◽  
Spark Ignition ◽  
Operating Conditions ◽  
Intake Manifold ◽  
Lean Burn ◽  
Spark Timing ◽  
Before And After ◽  
Heavy Duty Diesel ◽  
The One

Abstract Converting existing diesel engines to natural-gas (NG) spark-ignition (SI) operation can reduce the dependence on oil imports and increase energy security. NG-dedicated conversion can be achieved by the addition of a gas injector in the intake manifold and of a spark plug in place of the diesel injector. Previous studies indicated that lean-burn NG inside the traditional diesel chamber (i.e., a bowl-in-piston geometry) is a two-stage combustion (i.e., a fast burn inside the bowl followed by a slower burn inside the squish). However, a triple-peak apparent heat release rate (AHRR) was seen at specific operating conditions (e.g., advanced spark timing (ST) at medium load and engine speed), suggesting that one of the two combustion stages may separate again. Specifically, the burn inside the squish region divided in two events before and after top dead center (TDC). This was due to the different flow motion inside the squish during the compression stroke compared to the one in the expansion stroke, which affected the combustion environments. The result was the apparition of two close peaks in pressure trace, which suggest larger gradients in pressure and temperature than at a more delayed ST. In addition, the phasing and magnitude of three peaks of the heat release changed cycle-to-cycle. As an advanced ST is the usual strategy used in lean-burn SI combustion, understanding phenomena such as the one presented here can be important for reducing engine-out emissions and increase engine efficiency.

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