A mathematical model to investigate the effects of misfire and cyclic variations on crankshaft speed fluctuations in internal combustion engines

Constructive improvement of mobile energy means, in particular their main unit - the internal combustion engine, is directed on: maintenance of differentiation of size of parameters of functioning of mechanisms of systems depending on variability of conditions and modes of operation of cars; increase of technical resource at use of cars on purpose in the set operating conditions. The existing methods and tools for diagnosing vehicle engines do not fully determine their current technical condition, which requires the development of mathematical models to automate the process of diagnosing their components and parts was found іn the analysis of literature sources. The object of diagnosis is a diesel internal combustion engine of the YaMZ-238 family, which is part of the power unit of most vehicles. Mathematical model of automation of the process of diagnosing internal combustion engines of the YaMZ-238 family is presents in the article. Replacing real technical devices with their idealized models allows the widespread use of various mathematical methods. In this case, the internal combustion engine of the YaMZ-238 family, as the object of diagnosis, is presented in the form of a «black box», the input and output parameters of which have a finite set of values. In general, the mathematical model is a system of functional relationships between each diagnostic signal and structural parameters. For internal combustion engines of the YaMZ-238 family, a diagnostic matrix has been compiled, which includes a list of faults and signs of faults. It is determined that the process of diagnosis based on the model of the diagnostic object is possible if the inverse transformation of the number of signs of malfunctions into the number of structural parameters (malfunctions) of the object was unambiguous. The proposed mathematical model of automation of the process of diagnosing internal combustion engines of the family YaMZ-238 will detect faults of components and parts depending on their characteristics.

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Cylinder sleeve of the internal combustion engine. Mathematical model of the deformation process

Journal of Physics Conference Series ◽

10.1088/1742-6596/2131/2/022072 ◽

2021 ◽

Vol 2131 (2) ◽

pp. 022072

Author(s):

E Gubin ◽

S Andriushchenko ◽

K Mochalin

Keyword(s):

Mathematical Model ◽

Internal Combustion Engine ◽

Deformation Process ◽

Internal Combustion Engines ◽

Combustion Engine ◽

Internal Combustion ◽

Combustion Engines ◽

Two Stage ◽

Cylinder Sleeve ◽

Neutral Section

Abstract During the operation of internal combustion engines, deformation of the cylinder sleeve is possible, which causes its premature wear during the operation of the “piston ring – sleeve” pair. Imagine the sleeve as a two-stage hollow cylinder with forces applied to it, which cause deflection in the section. It can be assumed that if the greatest deformation of the cylinder is in the section of the application of forces, then with distance from this place it will decrease. At some distance from the point of application of forces, the deflection of the sleeve will be equal to zero. It is required to simulate a mathematical formula that would make it possible to evaluate the possibility of estimating the value depending on the basic geometric dimensions of the cylinder sleeve. A mathematical model of the deformation process of a hollow two-stage sleeve of an internal combustion engine has been developed, an analytical dependence has been obtained for the value of the “neutral” section depending on the main geometrical dimensions of the cylinder sleeve of the engine, a rather extensive analysis of the influence of various parameters on the value of the “neutral” section has been carried out.

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MODELLING OF INTERNAL COMBUSTION ENGINES’ EMISSION THROUGH THE USE OF TRAFFIC FLOW MATHEMATICAL MODELS

Transport ◽

10.3846/16484142.2011.621978 ◽

2011 ◽

Vol 26 (3) ◽

pp. 271-278 ◽

Cited By ~ 4

Author(s):

Raimundas Junevičius ◽

Marijonas Bogdevičius ◽

Ádám Török

Keyword(s):

Mathematical Model ◽

Traffic Flow ◽

Internal Combustion Engines ◽

Internal Combustion ◽

Flow Speed ◽

Model Description ◽

Regression Equations ◽

Combustion Engines ◽

Traffic Flows ◽

The Mathematical Model

Road traffic flows on a straight road segment are modelled in this article. The mathematical model of traffic flows has been constructed by using the method of lumped parameters. CO2, CO, CH, NOx, PM regression equations of internal combustion engines’ (ICE) emission has been developed. The accuracy of regression equations is 0.98÷0.99. The article presents assumptions for constructing the mathematical model, description of the mathematical model and gives simulation results. Traffic flow parameters, such as traffic flow concentration and traffic flow speed are presented as modelling results. ICE emission depending on the concentration and traffic flow speed are presented as well.

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Torsional Response of Internal Combustion Engines

Journal of Engineering for Industry ◽

10.1115/1.3438349 ◽

1974 ◽

Vol 96 (2) ◽

pp. 441-449 ◽

Cited By ~ 7

Author(s):

R. L. Eshleman

Keyword(s):

Mathematical Model ◽

Internal Combustion Engines ◽

Gasoline Engine ◽

Digital Simulation ◽

Internal Combustion ◽

Fourier Series Expansion ◽

Mode Shapes ◽

Combustion Engines ◽

Torsional Response ◽

Lumped Masses

A digital simulation technique for determining the torsional response of internal combustion engines subject to constant and pulsating end item torques is described herein. A refined mathematical model of the engine and end item power shafts is utilized to determine their natural frequencies, mode shapes, torsional motions and stresses using a digital computer. The mathematical model is composed of a finite number of elements which simulate lengths of continuous, massive, elastic shaft with end attached lumped masses and springs. Forcing functions, obtained by Fourier series expansion of the engine pressure-crank angle curve, are applied at the lumped masses. The technique is applied to a small gasoline engine attached to a reciprocating compressor and to a large Diesel engine with a constant torque end item.

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