Modeling of Equivalence Ratio Effects on Particulate Formation in a Spark-Ignition Engine under Premixed Conditions

2014 ◽  
Author(s):  
Qi Jiao ◽  
Rolf D. Reitz
Keyword(s):  
Equivalence Ratio ◽  
Spark Ignition ◽  
Spark Ignition Engine

First and Second Law Analyses of a Spark-Ignition Engine Using Either Isooctane or Hydrogen: An Initial Assessment

2006 ◽  
Author(s):  
Jerald A. Caton
Keyword(s):  
Nitric Oxide ◽  
Thermal Efficiency ◽  
Equivalence Ratio ◽  
Performance Metrics ◽  
Combustion Process ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Second Law ◽  
Cycle Simulation ◽  
Nitric Oxide Emissions

The use of either hydrogen or isooctane for a spark-ignition engine was examined using a thermodynamic cycle simulation including the second law of thermodynamics. The engine studied was a 5.7 liter, automotive engine operating from idle to wide open throttle. The hydrogen or isooctane was assumed premixed with the air. Two features of hydrogen combustion that were included in the study were the higher flame speeds (shorter burn durations) and the wider lean flammability limits (lean equivalence ratios). Three cases were considered for the use of hydrogen: (1) standard burn duration and an equivalence ratio of 1.0, (2) a shorter burn duration and an equivalence ratio of 1.0, and (3) a shorter burn duration and variable, lean equivalence ratios. The results included thermal efficiencies, other performance metrics, second law parameters, and nitric oxide emissions. In general, for the cases with an equivalence of 1.0, the brake thermal efficiency was slightly lower for the hydrogen cases due to the higher temperatures and higher heat losses. For the variable, lean equivalence ratio cases, the thermal efficiency was higher for the hydrogen case relative to the isooctane case. Due to the higher temperatures, the hydrogen cases had over 50% higher nitric oxide emissions compared to the isooctane case at the base conditions. In addition, the second law analyses indicated that the destruction of availability during the combustion process was lower for the base hydrogen case (11.2%) relative to the isooctane case (21.1%).

scholarly journals ANN Modelling of Propane-Powered 4-Stroke Spark Ignition Engine

2017 ◽  
Vol 11 (10) ◽  
pp. 1
Author(s):  
Jehad A. A. Yamin
Keyword(s):  
Experimental Data ◽  
Compression Ratio ◽  
Thermal Efficiency ◽  
Equivalence Ratio ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Ann Model ◽  
Spark Plug ◽  
Parametric Studies

An ANN model was developed by the authors and tested against experimental data available for an engine as supplied in the manual by the manufacturers. The model was found to perform excellently well by showing similar trends of performance for this engine as well as other engines for which the necessary data was available. This model was then used to perform some parametric studies to improve the performance of an engine using LPG (mainly Propane C3H8) as a fuel. This paper presents discussion on some of the parameters that affect the engine’s thermal efficiency with suggestions to improve it. The effect of equivalence ratio, compression ratio and spark plug location at different speeds on the thermal efficiency have been studied. Based on the engine and the range of variables studied it was found that the best spark plug location was 0.395 for all equivalence ratios studied at CR = 9.

Optimizing local charge stratification in a lean-burn spark ignition engine

1997 ◽  
Vol 211 (2) ◽  
pp. 145-154 ◽  
Author(s):  
C Arcoumanis ◽  
D. R. Hull ◽  
J. H. Whitelaw
Keyword(s):  
Equivalence Ratio ◽  
Peak Pressure ◽  
Spark Ignition ◽  
Flame Speed ◽  
Spark Ignition Engine ◽  
Local Injection ◽  
Combustion Pressure ◽  
Rich Mixture ◽  
Fuel Ratio ◽  
Homogeneous Charge

Gas pressure and local gas velocities have been measured in a single-cylinder spark ignition engine operating at low load and 1000 r/min and the results have characterized the extent to which combustion was enhanced by the injection of a small quantity of a mixture of propane vapour and air towards the spark plug in an otherwise quiescent chamber filled with a homogeneous lean propane/air charge. The effects of the locally generated mean flow/turbulence and equivalence ratio on combustion were examined separately by first injecting a mixture of equivalence ratio identical to that of the homogeneous charge and then a slightly rich mixture into homogeneous charges of lower equivalence ratios. The results show the advantageous effect of jet-induced local turbulence for overall air—fuel ratios between 17 and 24 with a maximum gain in peak pressure of 55 per cent at an air—fuel ratio of 20. The local injection of a rich mixture, in addition to increasing the gain in peak pressure from 30 to 50 per cent at an air—fuel ratio of 24, has extended the lean limit of the engine to 29. The timing of ignition relative to the end of injection, which varied as a function of the injection pressure, was found to have a strong effect on the peak combustion pressure so that, for example, a reduction of 8°(CA) in the time between the spark and the end of injection resulted in a 25 per cent reduction in combustion pressure at an air—fuel ratio of 22. The average flame speed was increased by local injection at all equivalence ratios; for example, a value of 7 m/s was obtained with local injection at an equivalence ratio of 0.7 which is equivalent to the flame speed measured with a homogeneous charge at the much higher equivalence ratio of 0.9.

scholarly journals Application of the Sectional Method to Investigate Particle Number and Soot Mass in Ethanol and Gasoline Fueled Premixed Spark Ignition Engines

2020 ◽  
Vol 197 ◽  
pp. 06009
Author(s):  
Valentina Pessina ◽  
Marco Del Pecchia ◽  
Sebastiano Breda ◽  
Luca Dalseno ◽  
Massimo Borghi
Keyword(s):  
Equivalence Ratio ◽  
Particle Number ◽  
Numerical Models ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Gasoline Direct Injection ◽  
Experimental Measurements ◽  
Pure Ethanol ◽  
Soot Mass ◽  
Wide Range

Emission modelling is still a timely topic in the engine research community. Soot emission reduction has gained its spotlight among the pollutants-related issues mainly due to the renewed interest in Gasoline Direct Injection. The conjunction of experimental measurements and numerical investigations provides an effective tool to cope with the constant evolution of the emission regulations. Thus, numerical models must be validated over a wide range of engine operating points and fuels. To this aim, the Sectional Method was applied to investigate Particulate Matter and Particle Number produced during combustion in a premixed spark ignition engine using 3D-CFD. Soot-related quantities were investigated for different values of equivalence ratio (from 1.0 up to 1.5) as well as for different fuels. Three different fuel types were examined: a commercial nonoxygenated American gasoline (TIER-2), a commercial Chinese gasoline (CHINA-6) with ethanol 10 %vol and pure Ethanol (E100). A detailed chemistry-based tabulated approach was exploited to compute a dedicated soot library, for each of the analyzed fuels, by means of 0D chemical kinetic simulations using a constant pressure reactor approach. Numerical results were compared to a database of experimental measurements collected from literature. The sooting tendency threshold dependency on equivalence ratio was also investigated and the results showed that the ethanol is the less sooting among the examined fuels, while the non-oxygenated gasoline exhibited the highest soot mass and Particle Number. This paper provides a CFD-based benchmark for soot mass and Particle Number for three fuel types with largely different chemical nature.

LPG Fueled Engine Under Kuwait Summer Climate

2002 ◽  
Author(s):  
Fuad N. Alasfour ◽  
Hassan K. Abdulraheem
Keyword(s):  
Co2 Emissions ◽  
Air Temperature ◽  
Equivalence Ratio ◽  
Engine Performance ◽  
Mechanical Efficiency ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Liquefied Petroleum Gas ◽  
Summer Climate ◽  
Brake Power

The purpose of this research is to investigate the effect of using LPG (liquefied petroleum gas) fuel on the performance of spark ignition engine under summer climate. A Hydra single-cylinder, spark ignition, water cooled engine was tested under elevated inlet air temperature. The effect of preheating inlet air from 25 to 60 °C to simulate Kuwait summer climate was investigated. Engine performance and the level of CO and CO2 emissions were measured experimentally using a gaseous Hydra research engine. The engine was fueled with local, commercial LPG. Several parameters were varied during the experimental work: fuel/air equivalence ratio, engine load and engine speed. The goal of this research was to investigate and simulate the effect of elevated inlet air temperature on the performance of car engine during summer season in Kuwait. The local LPG fuel is composed of 25% propane, 23% Iso-butane and 52% n-butane. Results show that the engine performance curves (brake power, brake specific fuel consumption and mechanical efficiency) have lower performance effect when inlet air temperature preheated from 25 to 60 °C, where the engine brake power dropped by 8% at equivalence ratio of 0.8. Carbon monoxide emission increased as inlet air preheated except at fuel air equivalence ratio less than 0.78. The present research provides a quantitative comparison of engine performance and CO and CO2 emissions between engine running at ambient and elevated inlet air temperature. Although there is a slight drop in the engine performance with heated inlet air, there is good reduction in the level of CO2.

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