scholarly journals Optimizing the Shape of a Compression-Ignition Engine Combustion Chamber by Using Simulation Tests

2019 ◽  
Vol 26 (3) ◽  
pp. 138-146
Author(s):  
Ireneusz Pielecha ◽  
Jerzy Merkisz
Keyword(s):  
Combustion Chamber ◽  
High Speed ◽  
Internal Combustion Engines ◽  
Combustion Process ◽  
Operating Conditions ◽  
Multidimensional Data ◽  
Compression Ignition ◽  
System Quality ◽  
Compression Ignition Engine ◽  
Engine Combustion

Abstract Modern solutions used in compression-ignition internal combustion engines are quite similar to each other. The use of high-pressure, direct fuel injection results in high combustion rates with controlled exhaust emissions. One of the combustion system quality criteria is to obtain adequately high thermodynamic indicators of the combustion process, which are obtained through, among others, the right combustion chamber geometry. Its shape influences the fuel atomization process, turbulence of fuel dose, evaporation and the combustion process. Optimizing the combustion chamber shape is one of the decisive factors proving the correct execution of the combustion process. This article presents the methodology of choosing the combustion chamber shape (changes of three selected combustion chamber dimensions) by using the optimization methods. Generating multidimensional data while maintaining the correlation structure was performed by using the Latin hypercube method. Chamber optimization was carried out by using the Nelder-Mead method. The combustion chamber shape was optimized for three engine load values (determined by the average indicated pressure) at selected engine operating conditions. The presented method of engine combustion chamber optimization can be used in low and high speed diesel propulsion engines (especially in maritime transport applications).

Parametric Study of Ignition and Combustion Characteristics From a Gasoline Compression Ignition Engine Using Two Different Reactivity Fuels

2016 ◽  
Author(s):  
Khanh Cung ◽  
Toby Rockstroh ◽  
Stephen Ciatti ◽  
William Cannella ◽  
S. Scott Goldsborough
Keyword(s):  
High Speed ◽  
Injection Pressure ◽  
Operating Conditions ◽  
Combustion Stability ◽  
Injection Timing ◽  
Strong Impact ◽  
Boost Pressure ◽  
Compression Ignition ◽  
Compression Ignition Engine ◽  
Ignition And Combustion

Unlike homogeneous charge compression ignition (HCCI) that has the complexity in controlling the start of combustion event, partially premixed combustion (PPC) provides the flexibility of defining the ignition timing and combustion phasing with respect to the time of injection. In PPC, the stratification of the charge can be influenced by a variety of methods such as number of injections (single or multiple injections), injection pressure, injection timing (early to near TDC injection), intake boost pressure, or combination of several factors. The current study investigates the effect of these factors when testing two gasoline-like fuels of different reactivity (defined by Research Octane Number or RON) in a 1.9-L inline 4-cylinder diesel engine. From the collection of engine data, a full factorial analysis was created in order to identify the factors that most influence the outcomes such as the location of ignition, combustion phasing, combustion stability, and emissions. Furthermore, the interaction effect of combinations of two factors or more was discussed with the implication of fuel reactivity under current operating conditions. The analysis was done at both low (1000 RPM) and high speed (2000 RPM). It was found that the boost pressure and air/fuel ratio have strong impact on ignition and combustion phasing. Finally, injection-timing sweeps were conducted whereby the ignition (CA10) of the two fuels with significantly different reactivity were matched by controlling the boost pressure while maintaining a constant lambda (air/fuel equivalence ratio).

Characterization of Tumble Motion in SI Engines: A New Parameter

2002 ◽  
Author(s):  
Pramod S. Mehta ◽  
M. Achuth
Keyword(s):  
Life Span ◽  
Combustion Chamber ◽  
Flow Analysis ◽  
Combustion Process ◽  
Operating Conditions ◽  
Mean Flow ◽  
Detailed Mechanism ◽  
Engine Combustion ◽  
Si Engines

A well-timed turbulence due to tumble in SI engines is found to be of substantial benefit to the engine combustion process. A mean flow analysis of tumble motion in conjunction with k-ε turbulence model has been developed to provide a detailed mechanism for turbulence enhancement due to tumble. Considering that the tumble phenomenon is highly geometry dependant, an attempt is made to relate tumble-generated turbulence to the parameters relating to intake conditions and combustion chamber geometry. Finally, a new parameter ‘vortex life span’ has been proposed to characterize tumble and its turbulence, which globally encompasses intake and combustion chamber related features. The sensitivity of this parameter is demonstrated at various operating conditions. It is found that the ‘vortex life span’ has an inverse relationship with commonly measured BDC tumble ratio and is more sensitive to the chamber geometry effects.

scholarly journals Simulation of Combustion Process of Diesel and Ethanol Fuel in Reactivity Controlled Compression Ignition Engine

CFD letters ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 1-11
Author(s):  
Fatin Farhanah Zulkurnai ◽  
Wan Mohd Faizal Wan Mahmood ◽  
Norhidayah Mat Taib ◽  
Mohd Radzi Abu Mansor
Keyword(s):  
Diesel Engine ◽  
High Speed ◽  
Combustion Process ◽  
Good Control ◽  
Injection Timing ◽  
Compression Ignition ◽  
Low Carbon ◽  
Compression Ignition Engine ◽  
Reactivity Controlled Compression Ignition ◽  
Complete Combustion

Reactivity controlled compression ignition (RCCI) engine give advantages over conventional diesel engine with the promising engine power and good control on NOx and soot emission. The trend of the RCCI concept is still new and Is very important to control the ignition in order to control the combustion progress and emission. The objective of this study is to provide data on the combustion characteristics and emission of diesel as high reactive, and ethanol as the low reactive fuel in the RCCI engine. The engine speed and injection timing were varied. Simulation work was conducted by using the Converge CFD software based on the Yanmar TF90 diesel engine parameter. Results show that operating the engine at low speed resulting in better engine performance and low carbon emissions due to the sufficient oxygen contents. For the high-speed engine, advancing the injection timing improves the fuel and air reactivity and steeper the equivalence ratio gradient, which result in a complete combustion process.

scholarly journals EFFECT OF CNG IN A FUEL DOSE ON THE COMBUSTION PROCESS OF A COMPRESSION-IGNITION ENGINE

Transport ◽  
2015 ◽  
Vol 30 (2) ◽  
pp. 162-171 ◽  
Author(s):  
Maciej Mikulski ◽  
Sławomir Wierzbicki
Keyword(s):  
Natural Gas ◽  
Combustion Chamber ◽  
Alternative Fuels ◽  
Combustion Process ◽  
Diesel Oil ◽  
Dual Fuel ◽  
Compression Ignition ◽  
Compression Ignition Engine ◽  
Compression Ignition Engines ◽  
Main Component

Currently, one of the major trends in the research of contemporary combustion engines involves the potential use of alternative fuels. Considerable attention has been devoted to methane, which is the main component of Natural Gas (NG) and can also be obtained by purification of biogas. In compression-ignition engines fired with methane or Compressed Natural Gas (CNG), it is necessary to apply a dual-fuel feeding system. This paper presents the effect of the proportion of CNG in a fuel dose on the process of combustion. The recorded time series of pressure in a combustion chamber was used to determine the repeatability of the combustion process and the change of fuel compression-ignition delay in the combustion chamber. It has been showed that NG does not burn completely in a dual-fuel engine. The best conditions for combustion are ensured with higher concentrations of gaseous fuel. NG ignition does not take place simultaneously with diesel oil ignition. Moreover, if a divided dose of diesel is injected, NG ignition probably takes place at two points, as diesel oil.

Evaluation of control-oriented flame propagation models for production control of a spark-assisted compression ignition engine

2021 ◽  
pp. 095440702110208
Author(s):  
Dennis Robertson ◽  
Robert Prucka
Keyword(s):  
Flame Propagation ◽  
Internal Combustion Engines ◽  
Production Control ◽  
Combustion Process ◽  
Data Driven ◽  
Efficient Production ◽  
Compression Ignition ◽  
Compression Ignition Engine ◽  
Advanced Combustion ◽  
Crank Angle

The drive to improve internal combustion engines has led to efficiency objectives that exceed the capability of conventional combustion strategies. As a result, advanced combustion modes are more attractive for production. These advanced combustion strategies typically add sensors, actuators, and degrees of freedom to the combustion process. Spark-assisted compression ignition (SACI) is an efficient production-viable advanced combustion strategy characterized by spark-ignited flame propagation that triggers autoignition in the remaining unburned gas. Modeling this complex combustion process for control demands a careful selection of model structure to maximize predictive accuracy within computational constraints. This work comprehensively evaluates a physics-based and a data-driven model. The physics-based model produces a burn duration by computing laminar flame speed as a function of test point conditions. The crank-angle domain is intentionally excluded to reduce computational expense. The data-driven model is an artificial neural network (ANN). The candidate models are compared to a one-dimensional engine model validated to experimental SACI engine data. Though both models capture the trends in burn rates, the ANN model has a root-mean square error (RMSE) of 1.4 CAD, significantly lower than the 10.4 CAD RMSE of the physics-based model. The exclusion of the crank-angle domain results in insufficient detail for the physics-based model, while the ANN can tolerate this exclusion.

scholarly journals Diagnosing of misfire events in compression-ignition engines with the help of vibroacoustic methods in the aspect of OBD system application in diesel locomotives

2008 ◽  
Vol 132 (1) ◽  
pp. 3-16
Author(s):  
Jerzy MERKISZ ◽  
Marek WALIGÓRSKI
Keyword(s):  
Internal Combustion Engines ◽  
Combustion Engine ◽  
High Reliability ◽  
Direct Injection ◽  
Combustion Process ◽  
Vibration Signal ◽  
Internal Combustion ◽  
Compression Ignition ◽  
Compression Ignition Engine ◽  
Railway Traction

The article concerns the possibilities of use of the method being able to assess of the combustion process and its lack in internal combustion engines of railway traction vehicles, that bases on the use of vibration signal parameters. The paper includes the results of research conducted on the engine test bench with a single cylinder research and compression-ignition engine with direct injection, and tests for the engine of a diesel locomotive in the exploitation condition. Possibility of the vibration signal estimators application to the assessment of a combustion process lack in an internal combustion engine and a high reliability of combustion process diagnostics basing on the above method have been proved.

scholarly journals Experimental Analysis of Engine Performance and Exhaust Pollutant on a Single-Cylinder Diesel Engine Operated Using Moringa Oleifera Biodiesel

2021 ◽  
Vol 11 (15) ◽  
pp. 7071
Author(s):  
Manzoore Elahi M. Soudagar ◽  
Haris Mehmood Khan ◽  
T. M. Yunus Khan ◽  
Luqman Razzaq ◽  
Tahir Asif ◽  
...  
Keyword(s):  
High Speed ◽  
Moringa Oleifera ◽  
Engine Performance ◽  
Operating Conditions ◽  
Compression Ignition ◽  
Compression Ignition Engine ◽  
Performance And Emission ◽  
High Speed Diesel ◽  
Moringa Oleifera Oil ◽  
Smoke Opacity

In this investigation, biodiesel was produced from Moringa oleifera oil through a transesterification process at operating conditions including a reaction temperature of 60 °C, catalyst concentration of 1% wt., reaction time of 2 h, stirring speed of 1000 rpm and methanol to oil ratio of 8.50:1. Biodiesel blends, B10 and B20, were tested in a compression ignition engine, and the performance and emission characteristics were analyzed and compared with high-speed diesel. The engine was operated at full load conditions with engine speeds varying from 1000 rpm to 2400 rpm. All the performance and exhaust pollutants results were collected and analyzed. It was found that MOB10 produced lower BP (7.44%), BSFC (7.51%), and CO2 (7.7%). The MOB10 also reduced smoke opacity (24%) and HC (10.27%). Compared to diesel, MOB10 also increased CO (2.5%) and NOx (9%) emissions.

scholarly journals The swirl ratio influence on combustion process and heat transfer in the opposed piston compression-ignition engine

2017 ◽  
Vol 170 (3) ◽  
pp. 3-7
Author(s):  
Tytus TULWIN ◽  
Mirosław WENDEKER ◽  
Zbigniew CZYŻ
Keyword(s):  
Combustion Chamber ◽  
Gas Flow ◽  
Fuel Injection ◽  
Combustion Process ◽  
Compression Ignition ◽  
Axially Symmetric ◽  
Piston Engine ◽  
Compression Ignition Engine ◽  
Automotive Engine ◽  
Combustion Gases

In order to maximise engine heat efficiency an engines charge flow must be properly designed -especially its swirl and tumble ratio. A two-stroke compression-ignition opposed piston engine reacts to engine swirl differently compared to a standard automotive engine with axially symmetric combustion chamber. In order to facilitate direct fuel injection, high-pressure injectors must be positioned from the side of combustion chamber. Depending on the combustion chamber geometry the swirling gases impact greatly how the injection stream is formed. If the deformation is too high the high temperature combustion gases can hit the piston surface or get into gaps between the pistons. This greatly affects the heat lost to the pistons and raises their local temperature. More atomised injection stream is more prone to swirling gas flow due to its reduced droplet size and momentum. The paper presents simulation results and analyses for different intake process induced swirl ratios and different types of combustion chambers in an experimental aviation opposed piston engine.

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