Systematic Reduction of Detailed Chemical Reaction Mechanisms for Engine Applications

2016 ◽  
Author(s):  
Lars Seidel ◽  
Corinna Netzer ◽  
Martin Hilbig ◽  
Fabian Mauss ◽  
Christian Klauer ◽  
...  
Keyword(s):  
Reaction Mechanism ◽  
Internal Combustion Engines ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Combustion Engines ◽  
Reactor Model ◽  
Mechanism Reduction ◽  
Rating Method ◽  
Chemical Reaction Mechanisms

In this work we apply a sequence of concepts for mechanism reduction on one reaction mechanism including novel quality control. We introduce a moment based accuracy rating method for species profiles. The concept is used for a necessity based mechanism reduction utilizing 0D reactors. Thereafter a stochastic reactor model (SRM) for internal combustion engines is applied to control the quality of the reduced reaction mechanism during the expansion phase of the engine. This phase is sensitive on engine out emissions, and is often not considered in mechanism reduction work. The proposed process allows to compile highly reduced reaction schemes for CFD application for internal combustion engine simulations. It is demonstrated that the resulting reduced mechanisms predict combustion and emission formation in engines with accuracies comparable to the original detailed scheme.

Systematic Reduction of Detailed Chemical Reaction Mechanisms for Engine Applications

2017 ◽  
Vol 139 (9) ◽  
Author(s):  
Lars Seidel ◽  
Corinna Netzer ◽  
Martin Hilbig ◽  
Fabian Mauss ◽  
Christian Klauer ◽  
...  
Keyword(s):  
Reaction Mechanism ◽  
Internal Combustion Engines ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Combustion Engines ◽  
Reactor Model ◽  
Mechanism Reduction ◽  
Rating Method ◽  
Chemical Reaction Mechanisms

In this work, we apply a sequence of concepts for mechanism reduction on one reaction mechanism including novel quality control. We introduce a moment-based accuracy rating method for species profiles. The concept is used for a necessity-based mechanism reduction utilizing 0D reactors. Thereafter a stochastic reactor model for internal combustion engines is applied to control the quality of the reduced reaction mechanism during the expansion phase of the engine. This phase is sensitive on engine out emissions, and is often not considered in mechanism reduction work. The proposed process allows to compile highly reduced reaction schemes for computational fluid dynamics application for internal combustion engine simulations. It is demonstrated that the resulting reduced mechanisms predict combustion and emission formation in engines with accuracies comparable to the original detailed scheme.

scholarly journals Improvement of the technology for controlling the parameters of the lubricating system of the D-245 diesel engine

2020 ◽  
pp. 163-171
Author(s):  
S.V. Timokhin ◽  
◽  
Yu.V. Rodionov ◽  
I.I. Kurbakov ◽  
◽  
...  
Keyword(s):  
Diesel Engine ◽  
Internal Combustion Engine ◽  
Cylinder Head ◽  
Internal Combustion Engines ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Engine Oil ◽  
Combustion Engines ◽  
Lubrication System

А significant factor affecting the reliability of the internal combustion engine and its technical and Economic indicators is the efficiency of the lubrication system. When the standard oil supply is applied, semiliquid friction occurs between the contacting parts, in which the parts are not completely separated by a layer of oil. However, with this friction, the required durability of components and parts with heat removal is guaranteed. The performance of the engine lubrication system is determined by the state of its elements (coarse and fine filters, oil radiator and pump, valves), as well as the quality of oil, its level in the internal combustion engine crankcase and temperature. In domestic internal combustion engines, the minimum oil level in the crankcase is controlled, but in operation there are situations when the oil level exceeds its maximum permissible value. This situation occurs when coolant or fuel enters the lubrication system. Coolant can get into the oil if the cylinder head gaskets, sleeve o-rings, or cracks in the cylinder head and block are broken. Top-Livo can enter the oil through worn and damaged parts of the fuel equipment (gas pump diaphragm, fuel pump plunger pairs, etc.). These liquids sharply degrade the quality of the oil and increase the wear of internal combustion engine parts, and the standard singlelevel indicator will not give the driver operational information about the malfunction. In connection with the above, the purpose of this work is to improve the technology for monitoring the technical condition of the internal combustion engine lubrication system on the example of the d-245 diesel engine and its modifications, which are widely used in GAZ (GAZ-3309), ZIL (ZIL-5301), MAZ (MAZ Zubrenok), PAZ buses (PAZ-3205), MTZ tractors (MTZ — 100, 892, 1020), agricultural and construction equipment.by developing and implementing a built — in device for monitoring the minimum and maximum oil levels in the crankcase, as well as its temperature. The scientific novelty of the work is due to the use of new circuit and technical solutions, as well as the original algorithm of the sensor operation developed by the authors, based on the use of switching laws of reed switches with normally closed and normally open contacts, the operation of which is spaced over time and controlled oil levels. Block diagram of the proposed device comprises a multifunction sensor level and oil temperature, including sensors of the mi-minimum and increased levels of engine oil in the crankcase of the engine and its temperature, the operation mode switch signal cooling temperature-edusei fluid and engine oil, the first and second voltage сomparators, indicator lights, buzzer, switch power supply, voltage regulator and regular temperature sensor coolant. The use of the developed device significantly increases the reliability and convenience of monitoring one of the most important indicators of internal combustion engines-the oil level in the crankcase, which will avoid significant engine damage. As a result of further research, it is planned to develop the device design, conduct laboratory studies of the developed multifunctional sensor in order to determine the dependence of its resistance on the temperature at the normal level of engine oil in the measuring flask, as well as determine the actual values of the developed sensor response heights at the lower and upper levels.

scholarly journals Electronic Study Guides for Applied Bachelor’s Degree Programs

2019 ◽  
Vol 28 (4) ◽  
pp. 134-141 ◽  
Author(s):  
D. V. Maltsev ◽  
E. M. Genson ◽  
D. S. Repetskiy
Keyword(s):  
Internal Combustion Engines ◽  
Field Experiments ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Bachelor's Degree ◽  
Remote Access ◽  
Degree Programs ◽  
Combustion Engines ◽  
Study Guides

The development of electronic study guides (ESG) for Bachelor’s disciplines enables to reduce procurement costs for print library collections. Posting of ESGs on the University Internet resources will provide their accessibility and usability, so the subject is topical. The article analyzes the experience of developing electronic study guides for the disciplines of basic professional bachelor’s degree programs in various universities and reviews the literature on this subject. The main features that distinguish ESG from paper teaching materials are the following: multimedia presentation of information, interactivity, dynamic content. In addition, remote interaction between a teacher and students in forums or video conferences is possible, depending on the format of the ESG. Furthermore, ESG allows one to remotely monitor the completeness and timeliness of the study of certain topics of the discipline, unlike other types of educational and methodological support. The implementation of the ESG makes it possible to maintain control in two forms: internal and external. There are also such criteria for assessing the quality of ESG as: proportion in ensuring the total volume of discipline, proportion in ensuring the self-directed student work, quality of design, the effectiveness of multimedia, adaptability, level of remote access. The result of the analysis was the development of requirements for the ESG design for the discipline «Structure and calculation of engines». This discipline includes the basics of structure and calculation elements and systems of internal combustion engines and the processes occurring in them. In Perm National Research Polytechnic University, according to the curriculum, the discipline is studied for 2 semesters; the labor intensity is 7 credits. Classroom lessons consist of lectures, laboratory and practical classes, additionally, coursework was provided. The difficulty of organizing and maintaining a laboratory in working condition is due to high labor and material costs for fuels and lubricants, electricity, forced-air ventilation, maintenance and repair of internal combustion engines, etc. In this regard, it is relevant to use simulation methods and create virtual laboratory benches to determine the characteristics of the internal combustion engine. These benches may be considered as an alternative to field experiments and stands. As a result of the generalization experience, it was possible to draw up general requirements to the structure and content of the ESG and to provide recommendations on the development of ESGs taking into account the specifics of applied bachelor’s programs.

Computationally Efficient Simulation of Multi-Component Fuel Combustion Using a Sparse Analytical Jacobian Chemistry Solver and High-Dimensional Clustering

2013 ◽  
Author(s):  
Federico Perini ◽  
Anand Krishnasamy ◽  
Youngchul Ra ◽  
Rolf D. Reitz
Keyword(s):  
Reaction Mechanism ◽  
Chemical Kinetics ◽  
Internal Combustion Engines ◽  
Combustion Engine ◽  
Engine Performance ◽  
Internal Combustion ◽  
Point Of View ◽  
High Dimensional ◽  
Computational Point ◽  
Fuel Surrogates

The need for more efficient and environmentally sustainable internal combustion engines is driving research towards the need to consider more realistic models for both fuel physics and chemistry. As far as compression ignition engines are concerned, phenomenological or lumped fuel models are unreliable to capture spray and combustion strategies outside of their validation domains — typically, high-pressure injection and high-temperature combustion. Furthermore, the development of variable-reactivity combustion strategies also creates the need to model comprehensively different hydrocarbon families even in single fuel surrogates. From the computational point of view, challenges to achieving practical simulation times arise from the dimensions of the reaction mechanism, that can be of hundreds species even if hydrocarbon families are lumped into representative compounds, and thus modeled with non-elementary, skeletal reaction pathways. In this case, it is also impossible to pursue further mechanism reductions to lower dimensions. CPU times for integrating chemical kinetics in internal combustion engine simulations ultimately scale with the number of cells in the grid, and with the cube number of species in the reaction mechanism. In the present work, two approaches to reduce the demands of engine simulations with detailed chemistry are presented. The first one addresses the demands due to the solution of the chemistry ODE system, and features the adoption of SpeedCHEM, a newly developed chemistry package that solves chemical kinetics using sparse analytical Jacobians. The second one aims to reduce the number of chemistry calculations by binning the CFD cells of the engine grid into a subset of clusters, where chemistry is solved and then mapped back to the original domain. In particular, a high-dimensional representation of the chemical state space is adopted for keeping track of the different fuel components, and a newly developed bounding-box-constrained k-means algorithm is used to subdivide the cells into reactively homogeneous clusters. The approaches have been tested on a number of simulations featuring multi-component diesel fuel surrogates, and different engine grids. The results show that significant CPU time reductions, of about one order of magnitude, can be achieved without loss of accuracy in both engine performance and emissions predictions, prompting for their applicability to more refined or full-sized engine grids.

scholarly journals Assessment of thermodynamic cycle of internal combustion engine in terms of rightsizing

2019 ◽  
Vol 178 (3) ◽  
pp. 182-186
Author(s):  
Zbigniew SROKA ◽  
Maciej DWORACZYŃSKI
Keyword(s):  
Internal Combustion Engine ◽  
Internal Combustion Engines ◽  
Combustion Engine ◽  
Combustion Process ◽  
Thermodynamic Cycle ◽  
Internal Combustion ◽  
Research Problem ◽  
Combustion Engines ◽  
Operating Characteristics ◽  
Swept Volume

The modification of the downsizing trend of internal combustion engines towards rightsizing is a new challenge for constructors. The change in the displacement volume of internal combustion engines accompanying the rightsizing idea may in fact mean a reduction or increase of the defining swept volume change factors and thus may affect the change in the operating characteristics as a result of changes in combustion process parameters - a research problem described in this publication. Incidents of changes in the displacement volume were considered along with the change of the compression space and at the change of the geometric degree of compression. The new form of the mathematical dependence describing the efficiency of the thermodynamic cycle makes it possible to evaluate the opera-tion indicators of the internal combustion engine along with the implementation of the rightsizing idea. The work demonstrated the in-variance of cycle efficiency with different forms of rightsizing.

FEATURES OF MEASURING THE CAMSHAFT OF INTERNAL COMBUSTION ENGINES

2021 ◽  
Vol 4 (30) ◽  
pp. 99-105
Author(s):  
A. V. Summanen ◽  
◽  
S. V. Ugolkov ◽  
Keyword(s):  
Internal Combustion Engine ◽  
Internal Combustion Engines ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Technical Condition ◽  
Combustion Engines

This article discusses the issues of assessing the technical condition of the camshaft, internal combustion engine. The necessary parameters for assessing the technical condition of the engine camshaft have been determined. How and how to measure and calculate this or that parameter is presented in detail. Methods for calculating the parameters are presented. A scheme and method for measuring neck wear, determining the height of the cam, determining the beating of the central journal of the camshaft are proposed. The main defects of the camshafts are presented. The issues of the influence of these parameters on the operability of the camshaft and the internal combustion engine as a whole are considered.

Possibility of using gas lubricant in the cylinders of internal combustion engines of transport vehicles

2021 ◽  
pp. 13-20
Author(s):  
Keyword(s):  
Internal Combustion Engine ◽  
Bearing Capacity ◽  
Power Plants ◽  
Internal Combustion Engines ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Combustion Engines ◽  
Engine Piston ◽  
Suspension Stiffness ◽  
Gas Layer

The prospects of using the gas-static suspension of the internal combustion engine piston in transport vehicles and power plants are considered. The diagram of the piston and the method for calculating the stiffness and bearing capacity of the gas layer surrounding the piston are presented, as well as the results of experiments that showed the relevance of this method. The possibility of gas and static centering of the engine piston is confirmed. Keywords: internal combustion engine, piston, gasstatic suspension, stiffness, bearing capacity, gas medium. [email protected]

Calculation of Acoustic Efficiency of Exhaust Silencers for Automotive Internal Combustion Engines

2021 ◽  
pp. 41-47
Author(s):  
Vladimir Tupov ◽  
O. Matasova
Keyword(s):  
Acoustic Waves ◽  
Internal Combustion Engines ◽  
Combustion Engine ◽  
Control Point ◽  
Plane Waves ◽  
Exhaust System ◽  
Internal Combustion ◽  
Combustion Engines ◽  
Exhaust Noise ◽  
Insertion Losses

Insertion losses as the main characteristic that mathematically describes the acoustic efficiency of a noise silencer has been considered. This characteristic shows the reduction of noise generated by its source, in particular by the internal combustion engine’s exhaust system, at the control point as a silencer use result. Has been presented a mathematical description of the insertion losses, and have been considered parameters necessary for calculating this characteristic. Has been demonstrated the analytical dependence of impedance for the sound emission by the exhaust system’s end hole from the coefficient of acoustic waves reflection by this hole. The performed analysis of the widely used formulas for calculating the coefficient of sound reflection by the end hole has showed their insufficient accuracy for project designs performing. Have been proposed calculation dependences providing high accuracy for calculations of the reflection coefficient modulus, and the attached length of the channel end hole without a flange in the entire range of the existence of plane waves in it. It has been shown that the end correction of this hole at ka = 0 is 0.6127, and not 0.6133, as it was mistakenly believed until now in world acoustics. Has been proposed a method for calculation the exhaust noise source internal impedance. This method more accurately, in comparison with the already known ones, describes the acoustic processes in the internal combustion engine’s exhaust manifold, thanks to increases the accuracy of calculation the silencer acoustic efficiency, that allows develop the silencer at the early stages of the design of an automotive internal combustion engine.

A Novel Way of Manipulating and Optimizing CAM Profiles for Internal Combustion Engines

2007 ◽  
Author(s):  
Satheesh Makkapati ◽  
Kim Ku ◽  
Steve Poe
Keyword(s):  
Internal Combustion Engines ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Combustion Engines ◽  
Computationally Efficient ◽  
Trade Offs ◽  
Cam Profile ◽  
Computer Codes ◽  
Tool Optimization ◽  
Automated Tool

Generating an optimum cam profile for an internal combustion engine application is usually a very involved process. This is because of the challenge faced by the engine engineers to perform several trade-offs between fuel economy, performance, durability and emissions. Typically, the trade offs are worked out using several computer codes and with the involvement of a cross-functional team of engineers. Hence, there is a need to develop a tool that can encapsulate the various computer codes and can manipulate the cam profile with ease. With the existence of such an automated tool, optimization of the cam profile can be achieved with a specified trade-off between the several metrics identified above. This paper describes the development of such a tool, and discusses the ingredients that make it flexible and computationally efficient. Results from the use of this tool are documented in this paper as well.

Performance study of the hypocycloid gear mechanism for internal combustion engine applications

2019 ◽  
pp. 146808741989358 ◽  
Author(s):  
Mostafa A ElBahloul ◽  
ELsayed S Aziz ◽  
Constantin Chassapis
Keyword(s):  
Internal Combustion Engine ◽  
Thermodynamic Model ◽  
Internal Combustion Engines ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Combustion Engines ◽  
Otto Cycle ◽  
Engine Efficiency ◽  
Gear Mechanism ◽  
Crank Mechanism

Fuel conversion efficiency is one of the main concerns in the field of internal combustion engine systems. Although the Otto cycle delivers the maximum efficiency possible in theory, the kinematics of the slider–crank mechanism of the conventional internal combustion engines makes it difficult to reach this level of efficiency in practice. This study proposes using the unique hypocycloid gear mechanism instead of the conventional slider–crank mechanism for the internal combustion engines to increase engine efficiency and minimize frictional power losses. The hypocycloid gear mechanism engine’s kinematics provides the means for the piston-rod assembly to reciprocate in a straight-line motion along the cylinder axis besides achieving a nonlinear rate of piston movement. As a result, this characteristic allows for a true constant-volume combustion, which in turn would lead to higher work output. An in-cylinder gas volume change model of the hypocycloid gear mechanism engine was developed and incorporated into the thermodynamic model for the internal combustion engine cycle. The thermodynamic model of the hypocycloid gear mechanism engine was developed and simulated using MATLAB/Simulink software. A comparison between the conventional engine and the hypocycloid gear mechanism engine in terms of engine performance characteristics showed the enhancements achieved using hypocycloid gear mechanism for internal combustion engine applications. The hypocycloid gear mechanism engine analysis results indicated higher engine efficiency approaching that of the Otto cycle.

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