scholarly journals Experimental assessment of new insulation coatings for lean burn spark-ignited engines

2020 ◽  
Vol 75 ◽  
pp. 11 ◽  
Author(s):  
Jérôme Chérel ◽  
Jean-Marc Zaccardi ◽  
Bernard Bouteiller ◽  
Alain Allimant
Keyword(s):  
Heat Conductivity ◽  
Internal Combustion Engines ◽  
Thermal Environment ◽  
Positive Impact ◽  
Atmospheric Plasma ◽  
Lean Burn ◽  
Single Cylinder ◽  
Gasoline Engines ◽  
Single Cylinder Engine ◽  
Temperature Swing

Clean and highly efficient internal combustion engines will still be necessary in the future to meet the ambitious CO2 emissions reduction targets set for light-duty vehicles. The maximal efficiency of stoichiometric Spark-Ignited (SI) gasoline engines has been steadily increasing in recent years but remains limited by the important relative share of cooling losses. Low heat rejection engines using ceramic barrier coatings have been presented in the past but smart insulation coatings are gaining a renewed interest as a more promising way to further increase the engine maximal thermal efficiency. This article is highlighting some important effects of smart insulation coatings developed for lean-burn spark-ignited gasoline engines. Five different coatings with low heat conductivity and capacity are applied on aluminum engine parts with the atmospheric plasma spray technique and are tested with two different engines. The laser induced phosphorescence technique is firstly used in an optical single cylinder engine to quantify the thermal performance of these coatings in terms of temperature swing during combustion. A maximal increase in the piston surface temperature of around 100 °C is measured at low load, confirming thus the expected impact of the low heat conductivity and capacity, and suggesting thus a positive impact on fuel consumption. Thanks to the tests performed with a similar metal single cylinder engine, it is shown that the unburned hydrocarbon emissions can significantly increase by up to 25% if the open porosity on top of the coating is not properly sealed, while the surface roughness has no impact on these emissions. When applied on both the piston and the cylinder head, the optimized coating displays some distinct effects on the maximal heat release rate and NOx emissions, indicating that the thermal environment inside the combustion chamber is modified during combustion. Thanks to the temperature swing between cold and hot engine phases the volumetric efficiency can also be kept constant. However, no increase in efficiency can be measured with this optimized coating which suggests that the heat balance is not affected only by the reduction in the temperature differential between the walls and the gas.

scholarly journals Comparative study on combustion characteristics of lean premixed CH4/air mixtures in RCM using spark ignition and turbulent jet ignition in terms of orifices angular position change

2019 ◽  
Vol 176 (1) ◽  
pp. 36-41 ◽  
Author(s):  
Wojciech BUESCHKE ◽  
Maciej SKOWRON ◽  
Krzysztof WISŁOCKI ◽  
Filip SZWAJCA
Keyword(s):  
Internal Combustion Engines ◽  
Positive Impact ◽  
Angular Position ◽  
Turbulent Jet ◽  
Combustion Stability ◽  
Optical Observations ◽  
Charge Movement ◽  
Position Change ◽  
Lean Burn ◽  
The Impact

The increase in ignitability consist a main aim of implementation of the turbulent jet ignition (TJI) in relation to the combustion of diluted charges. Such an ignition system has been introduced to the lean-burn CNG engine in the scope of GasOn-Project (Gas Only Internal Combustion Engines). In this study the impact of TJI application on the main combustion indexes has been investigated using RCM and analyzed on the bases of the indicating and optical observations data. The images have been recorded using LaVision HSS5 camera and post-processed with Davis software. Second part of the study based on indicating measurements consist the analysis of combustion regarding the variation in the geometry of pre-chamber nozzles. It has been noted, that combustion with TJI indicates signi- ficantly bigger flame luminescence and simultaneously – faster flame front development, than the combustion initiated with conventional SI. The positive impact of nozzles angular position on engine operational data has been found in the static charge movement conditions, regarding the combustion stability.

Sensitivity Analysis of the Air Flow inside a Single Cylinder Engine for Different Turbulence Models Using CFD

2014 ◽  
Vol 1016 ◽  
pp. 624-629
Author(s):  
Felipe Grossi L. Amorim ◽  
Jean Helder M. Ribeiro ◽  
Marília Gabriela J. Vaz ◽  
Ramon Molina Valle
Keyword(s):  
Internal Combustion Engines ◽  
Turbulence Models ◽  
Internal Combustion ◽  
Combustion Engines ◽  
Single Cylinder ◽  
Greenhouse Gases Emissions ◽  
Single Cylinder Engine ◽  
Computational Resources ◽  
Experimental Pressure

Theincrease of greenhouse gases emissions makes necessary to improve the comprehension of the Internal Combustion Engines operation. One of the factors that affect the combustion in these engines is the turbulence, since it can raise the quality of the fuel-air mixture inside the combustion chamber. However, when modeling internal combustion engines using CFD, the turbulence model choice is always a relevant problem. The present paper analyzes the results for three different turbulence models (k-ε Realizable, RNG k-ε and Menter k-ω SST) ina single-cylinder engine geometry, comparing numerical and experimental pressure data. For this experiment, the k-ε models obtained more trustable results than the k-ω SST, using less computational resources. The models achieved good results for eddy recirculation inside de cylinder and in regions of free shear flow at the valve openings, which makes possible to observe the correlation between parameters such as tumble and turbulent kinetic energy.

Direct use of biomass powder in internal combustion engines

2019 ◽  
Vol 3 (10) ◽  
pp. 2763-2770 ◽  
Author(s):  
L. Stover ◽  
B. Piriou ◽  
C. Caillol ◽  
P. Higelin ◽  
C. Proust ◽  
...  
Keyword(s):  
Internal Combustion Engines ◽  
Internal Combustion ◽  
Combustion Engines ◽  
Single Cylinder ◽  
Single Cylinder Engine ◽  
Direct Use ◽  
Engine Concept

A first general assessment of the biomass dust-fuelled engine concept by testing four biomass powders in a single-cylinder engine.

scholarly journals Monitoreo de Condición en Motores de Combustión Interna Monocilíndricos con Base en Adquisición y Procesamiento de Señales Experimentales

2018 ◽  
Vol 3 (1) ◽  
pp. 736
Author(s):  
Daniela Torres M ◽  
Héctor F. Quintero R ◽  
Juan F. López L ◽  
Álvaro A. Orozco G
Keyword(s):  
Condition Monitoring ◽  
Signal Analysis ◽  
Internal Combustion Engines ◽  
Vibration Signal ◽  
Internal Combustion ◽  
Signal Acquisition ◽  
Combustion Engines ◽  
Cylinder Pressure ◽  
Single Cylinder ◽  
Single Cylinder Engine

In recent years, condition monitoring based on signal analysis has become a valuable tool for the diagnosis of internal combustion engines. In this paper the experimental design for the ICE monitoring condition, based on signal analysis, is presented. The experimental configuration was development for the analysis of signals from ICE in order to monitor their condition. The conduced case study consists on the monitoring condition of a single-cylinder engine, operating under regular conditions and different speeds. The instrumentation, the adquisition systems as well as the signals analysis are also presented. The adquired signals were: engine block vibration, in-cylinder pressure and crankshaft speed. The mentioned signals were analyzed and processed by FFT and Rigid Regression. It was possible to obtain the frequency spectrum of the vibration signal and reconstruct the in-cylinder pressure of the single-cylinder engine. The presented configuration can be taken as a basis for the evaluation of others engines and for improving the schemes of monitoring condition.Keywords: Internal combustion engines, condition monitoring, signal acquisition, signal processing.

A phenomenological model for the description of unburned hydrocarbons emission in ultra-lean engines

2021 ◽  
pp. 146808742110050
Author(s):  
Enrica Malfi ◽  
Vincenzo De Bellis ◽  
Fabio Bozza ◽  
Alberto Cafari ◽  
Gennaro Caputo ◽  
...  
Keyword(s):  
Natural Gas ◽  
Internal Combustion Engines ◽  
Pollutant Emissions ◽  
Average Error ◽  
Combustion Engines ◽  
Nitric Oxides ◽  
Lean Burn ◽  
Fuel Charge ◽  
Unburned Hydrocarbons ◽  
Model Reliability

The adoption of lean-burn concepts for internal combustion engines working with a homogenous air/fuel charge is under development as a path to simultaneously improve thermal efficiency, fuel consumption, nitric oxides, and carbon monoxide emissions. This technology may lead to a relevant emission of unburned hydrocarbons (uHC) compared to a stoichiometric engine. The uHC sources are various and the relative importance varies according to fuel characteristics, engine operating point, and some geometrical details of the combustion chamber. This concern becomes even more relevant in the case of engines supplied with natural gas since the methane has a global warming potential much greater than the other major pollutant emissions. In this work, a simulation model describing the main mechanisms for uHC formation is proposed. The model describes uHC production from crevices and flame wall quenching, also considering the post-oxidation. The uHC model is implemented in commercial software (GT-Power) under the form of “user routine”. It is validated with reference to two large bore engines, whose bores are 31 and 46 cm (engines named accordingly W31 and W46). Both engines are fueled with natural gas and operated with lean mixtures (λ > 2), but with different ignition modalities (pre-chamber device or dual fuel mode). The engines under study are preliminarily schematized in the 1D simulation tool. The consistency of 1D engine schematizations is verified against the experimental data of BMEP, air flow rate, and turbocharger rotational speed over a load sweep. Then, the uHC model is validated against the engine-out measurements. The averaged uHC predictions highlight an average error of 7% and 10 % for W31 and W46 engines, respectively. The uHC model reliability is evidenced by the lack of need for a case-dependent adjustment of its tuning constants, also in presence of relevant variations of both engine load and ring pack design.

A Transient Single Cylinder Test System for Engine Research and Control Development

2005 ◽  
Author(s):  
John L. Lahti ◽  
Matthew W. Snyder ◽  
John J. Moskwa
Keyword(s):  
Test System ◽  
Intake Manifold ◽  
Test Accuracy ◽  
Test Configuration ◽  
Single Cylinder ◽  
Cylinder Test ◽  
Single Cylinder Engine ◽  
Wide Range ◽  
Reduce Development Time ◽  
High Bandwidth

A transient test system was developed for a single cylinder research engine that greatly improves test accuracy by allowing the single cylinder to operate as though it were part of a multi-cylinder engine. The system contains two unique test components: a high bandwidth transient hydrostatic dynamometer, and an intake airflow simulator. The high bandwidth dynamometer is used to produce a speed trajectory for the single cylinder engine that is equivalent to that produced by a multi-cylinder engine. The dynamometer has high torque capacity and low inertia allowing it to simulate the speed ripple of a multi-cylinder engine while the single cylinder engine is firing. Hardware in loop models of the drivetrain and other components can be used to test the engine as though it were part of a complete vehicle, allowing standardized emissions tests to be run. The intake airflow simulator is a specialized intake manifold that uses solenoid air valves and a vacuum pump to draw air from the manifold plenum in a manner that simulates flow to other engine cylinders, which are not present in the single cylinder test configuration. By regulating this flow from the intake manifold, the pressure in the manifold and the flow through the induction system are nearly identical to that of the multi-cylinder application. The intake airflow simulator allows the intake runner wave dynamics to be more representative of the intended multi-cylinder application because the appropriate pressure trajectory is maintained in the intake manifold plenum throughout the engine cycle. The system is ideally suited for engine control development because an actual engine cylinder is used along with a test system capable of generating a wide range of transient test conditions. The ability to perform transient tests with a single cylinder engine may open up new areas of research exploring combustion and flow under transient conditions. The system can also be used for testing the engine under conditions such as cylinder deactivation, fuel cut-off, and engine restart. The improved rotational dynamics and improved intake manifold dynamics of the test system allow the single cylinder engine to be used for control development and emissions testing early in the engine development process. This can reduce development time and cost because it allows hardware problems to be identified before building more expensive multi-cylinder engines.

Laser-Spark Ignition Testing in a Natural Gas-Fueled Single-Cylinder Engine

2004 ◽  
Author(s):  
Michael McMillian ◽  
Steven Richardson ◽  
Steven D. Woodruff ◽  
Dustin McIntyre
Keyword(s):  
Natural Gas ◽  
Spark Ignition ◽  
Single Cylinder ◽  
Single Cylinder Engine ◽  
Laser Spark ◽  
Gas Fueled ◽  
Laser Spark Ignition

Tumble Flow Measurements Using Three Different Methods and Its Effects on Fuel Economy and Emissions

2006 ◽  
Author(s):  
Myoungjin Kim ◽  
Sihun Lee ◽  
Wootae Kim
Keyword(s):  
Fuel Economy ◽  
High Performance ◽  
Gasoline Engine ◽  
Exhaust Emissions ◽  
Combustion Stability ◽  
Lean Burn ◽  
Flow Measurements ◽  
Part Load ◽  
Gasoline Engines ◽  
Dynamometer Test

In-cylinder flows such as tumble and swirl have an important role on the engine combustion efficiencies and emission formations. In particular, the tumble flow, which is dominant in-cylinder flow in current high performance gasoline engines, has an important effect on the fuel consumptions and exhaust emissions under part load conditions. Therefore, it is important to know the effect of the tumble ratio on the part load performance and optimize the tumble ratio of a gasoline engine for better fuel economy and exhaust emissions. First step in optimizing a tumble flow is to measure a tumble ratio accurately. In this research the tumble flow was measured, compared and correlated using three different measurement methods: steady flow rig, 2-Dimensional PIV, and 3-Dimensional PTV. Engine dynamometer test was performed to find out the effect of the tumble ratio on the part load performance. Dynamometer test results of high tumble ratio engine showed faster combustion speed, retarded MBT timing, higher exhaust emissions, and a better lean burn combustion stability. Lean limit of the baseline engine was expanded from A/F=18:1 to A/F=21:1 by increasing a tumble ratio using MTV.

Optimization of Mode Switching Timing Control for a Lean-Burn Gasoline Engine With a Prototype Passive SCR System

2018 ◽  
Author(s):  
Dakota Strange ◽  
Pingen Chen ◽  
Vitaly Y. Prikhodko ◽  
James E. Parks
Keyword(s):  
Gasoline Engine ◽  
Nox Reduction ◽  
Cost Effective ◽  
Nox Storage ◽  
Mode Switching ◽  
Timing Control ◽  
Lean Burn ◽  
Gasoline Engines ◽  
Effective Manner ◽  
Passive Scr

Passive selective catalytic reduction (SCR) has emerged as a promising NOx reduction technology for highly-efficient lean-burn gasoline engines to meet stringent NOx emission regulation in a cost-effective manner. In this study, a prototype passive SCR which includes an upstream three-way catalyst (TWC) with added NOx storage component, and a downstream urealess SCR catalyst, was investigated. Engine experiments were conducted to investigate and quantify the dynamic NOx storage/release behaviors as well as dynamic NH3 generation behavior on the new TWC with added NOx storage component. Then, the lean/rich mode-switching timing control was optimized to minimize the fuel penalty associated with passive SCR operation. Simulation results show that, compared to the baseline mode-switching timing control, the optimized control can reduce the passive SCR-related fuel penalty by 6.7%. Such an optimized mode-switching timing control strategy is rather instrumental in realizing significant fuel efficiency benefits for lean-burn gasoline engines coupled with cost-effective passive SCR systems.

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