IMPROVING THE ACCURACY OF DETERMINING THE FREQUENCY

2021 ◽  
Vol 73 (2) ◽  
pp. 23-31
Author(s):  
L.O. SAVIN ◽  
Keyword(s):  
Internal Combustion Engines ◽  
Internal Combustion ◽  
Road Transport ◽  
Technical Condition ◽  
Operating Conditions ◽  
Combustion Engines ◽  
Optimal Frequency ◽  
Average Operating

The paper substantiates a method for increasing the accuracy of determining the optimal fre-quency of maintenance of one of the most important units of automotive equipment operating in various climatic and road transport conditions - its engines, and also presents circuit proposals for the implementation of this method. The proposed approach makes it possible to significantly increase the accuracy of determining the optimal frequency of maintenance of internal combustion engines by taking into account their real technical condition when operating in different (different from the average) operating conditions. The article provides typical examples of calculating the determination of the optimal frequency of maintenance of automotive equipment, and also estimates the gain achieved when using the approach proposed in the work.

scholarly journals The influence of centrial forces on crankshaft bearing lubrication is in emergency modes of the engine of the car

2021 ◽  
Vol 12 (2) ◽  
pp. 112-121
Author(s):  
Oleksandr Khrulev ◽  
◽  
Olexii Saraiev ◽  
Iryna Saraieva ◽  
◽  
...  
Keyword(s):  
Internal Combustion Engines ◽  
Operating Mode ◽  
Internal Combustion ◽  
Technical Condition ◽  
Operating Conditions ◽  
Combustion Engines ◽  
Connecting Rod ◽  
Oil Supply ◽  
Technical Expert ◽  
The Difference

The analysis of the crankshaft bearing condition of the automotive internal combustion engines in the case of insufficiency and breakage of oil supply to them is carried out. It is noted that this fault is one of the most common causes of damage to rubbing pairs in operation. At the same time, the different groups of bearings are often damaged, which cannot be explained within the framework of existing models of plain bearing lubrication. The objective of the work is to develop a mathematical model of oil supply to connecting rod bearings in emergency mode, taking into account the characteristic features of the bearing design. The model also, depending on the nature of the damage, should help to determine and explain the causes of bearing failures if they occur in different modes when operating conditions are broken. A computational model has been developed that makes it possible to assess the effect of design differences in the features of oil supply and the action of the centrifugal forces during crankshaft rotation on the oil column in the lubrication hole where oil is supplied to the conrod bearing. Calculations of the change in time of the oil supply pressure to the connecting rod bearings for the various designs of the crankshaft lubrication holes have been performed. It is shown that, depending on the operating mode of the engine and its design, the oil pressure in front of the connecting rod bearings does not disappear immediately after oil supply failure to crankshaft. Moreover, the lower the crankshaft speed is, the longer the lubrication of the conrod bearings will continue. The calculation results are confirmed by the data of the expert studies of the engine technical condition, in which the crankshaft was wedged in the damaged main bearings was found in the absence of serious damage to the connecting rod ones. It has been found that such features of the damage correspond to an rapid breakage of the oil supply to the crankshaft in the case of such operational damage as the oil pump and pressure reducing valve failure, the oil filter seal and oil pan destruction, etc. The developed model explains the difference in lubrication conditions and in the damage feature to the main and connecting rod bearings in the emergency cases of the oil supply breakage, which are observed during operation, and helps to clarify the failure causes. This makes it possible to use the model and the obtained data when providing auto technical expert studies of the failure causes of automobile internal combustion engines This makes it possible to use the model and the obtained data when providing auto technical expert studies of the failure causes of automobile internal combustion engines when the operating conditions are broken.

scholarly journals The use of thermography in the diagnosis of ship piston internal combustion engines

2018 ◽  
Vol 182 ◽  
pp. 01027
Author(s):  
Jan Monieta
Keyword(s):  
Infrared Thermography ◽  
Internal Combustion Engines ◽  
Experimental Studies ◽  
Internal Combustion ◽  
Technical Condition ◽  
Operating Conditions ◽  
Combustion Engines ◽  
Destructive Testing ◽  
Fault State ◽  
Floating Objects

The intensity of infrared radiation emitted by objects depends mainly on their temperature. One of the diagnostic signals may be the temperature field. In infrared thermography, this quantity is used as an indicator of the technical condition of marine objects. The article presents an overview of the use of infrared thermography for the diagnosis mainly of marine piston floating objects and various types of reciprocating internal combustion engines as well as examples of own research results. A general introduction to infrared thermography and common procedures for temperature measurement and non-destructive testing are presented. Experimental research was carried out both in laboratory conditions and in the operating conditions of sea-going vessels. Experimental studies consisted of the presentation of photographs of the same objects made in visible light and the use of infrared thermography. The same objects were also compared, but for different cylinders of the tested internal combustion engines as well as for the up state and fault state. The characteristics of the temperature values at selected points were taken depending on the engine load along with the approximation mathematical models of these dependencies.

scholarly journals Selected Tribological Properties of A390.0 Alloy

2017 ◽  
Vol 17 (4) ◽  
pp. 175-178 ◽  
Author(s):  
R. Wieszała ◽  
J. Piątkowski
Keyword(s):  
Internal Combustion Engines ◽  
Internal Combustion ◽  
Operating Conditions ◽  
Combustion Engines ◽  
New Materials ◽  
Surface Distribution ◽  
Distribution Of Elements ◽  
Piston System ◽  
Pin On Disc

AbstractEmergence of new designs for internal combustion engines resulted in a necessity to search for new materials which will rise to excessive technological requirements under operating conditions of modern internal combustion engines of up to 150 kW. Focusing only on material properties, theoretically existing alloys should meet presents requirements. More importantly, existing materials are well fitted to the entire crank-piston system. Thus, there is a need for a more thorough examination of these materials. The paper presents studies on determination of coefficient of friction μ and wear for the A390.0 alloy modified with AlTi5B master alloy combined with EN GJL-350 cast iron. The characteristics of a T-11 tribological tester (pin on disc) used for the tests, as well as the methodology of the tribological tests, were described. Also, the analysis of the surface distribution of elements for the pin and the disc was presented. The studies were realized in order to find whether the analyzed alloy meets the excessive requirements for the materials intended for pistons of modern internal combustion engines. The results show that the A390.0 alloy can only be applied to a load of 1.4 MPa. Above this value was observed destructive wear, which results in the inability to use it in modern internal combustion engines.

scholarly journals Exhaust Gas Temperature Measurements in Diagnostics of Turbocharged Marine Internal Combustion Engines Part I Standard Measurements

2015 ◽  
Vol 22 (1) ◽  
pp. 47-54 ◽  
Author(s):  
Zbigniew Korczewski
Keyword(s):  
Internal Combustion Engines ◽  
Internal Combustion ◽  
Technical Condition ◽  
Temperature Measurements ◽  
Injection System ◽  
Exhaust Gas ◽  
Combustion Engines ◽  
Gas Temperature ◽  
Measuring Signal ◽  
Exhaust Gas Temperature

Abstract The article discusses the problem of diagnostic informativeness of exhaust gas temperature measurements in turbocharged marine internal combustion engines. Theoretical principles of the process of exhaust gas flow in turbocharger inlet channels are analysed in its dynamic and energetic aspects. Diagnostic parameters are defined which enable to formulate general evaluation of technical condition of the engine based on standard online measurements of the exhaust gas temperature. A proposal is made to extend the parametric methods of diagnosing workspaces in turbocharged marine engines by analysing time-histories of enthalpy changes of the exhaust gas flowing to the turbocompressor turbine. Such a time-history can be worked out based on dynamic measurements of the exhaust gas temperature, performed using a specially designed sheathed thermocouple. The first part of the article discusses possibilities to perform diagnostic inference about technical condition of a marine engine with pulse turbocharging system based on standard measurements of exhaust gas temperature in characteristic control cross-sections of its thermal and flow system. Selected metrological issues of online exhaust gas temperature measurements in those engines are discusses in detail, with special attention being focused on the observed disturbances and thermodynamic interpretation of the recorded measuring signal. Diagnostic informativeness of the exhaust gas temperature measurements performed in steady-state conditions of engine operation is analysed in the context of possible evaluations of technical condition of the engine workspaces, the injection system, and the fuel delivery process.

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.

scholarly journals A zonal approach for estimating pressure ratio at compressor extreme off-design conditions

2018 ◽  
Vol 20 (4) ◽  
pp. 393-404 ◽  
Author(s):  
José Galindo ◽  
Roberto Navarro ◽  
Luis Miguel García-Cuevas ◽  
Daniel Tarí ◽  
Hadi Tartoussi ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
High Speed ◽  
Internal Combustion Engines ◽  
Pressure Ratio ◽  
Internal Combustion ◽  
Operating Conditions ◽  
Combustion Engines ◽  
One Dimensional ◽  
Performance Map

Zero-dimensional/one-dimensional computational fluid dynamics codes are used to simulate the performance of complete internal combustion engines. In such codes, the operation of a turbocharger compressor is usually addressed employing its performance map. However, simulation of engine transients may drive the compressor to work at operating conditions outside the region provided by the manufacturer map. Therefore, a method is required to extrapolate the performance map to extended off-design conditions. This work examines several extrapolating methods at the different off-design regions, namely, low-pressure ratio zone, low-speed zone and high-speed zone. The accuracy of the methods is assessed with the aid of compressor extreme off-design measurements. In this way, the best method is selected for each region and the manufacturer map is used in design conditions, resulting in a zonal extrapolating approach aiming to preserve accuracy. The transitions between extrapolated zones are corrected, avoiding discontinuities and instabilities.

A Novel Electromechanical Solution for Cam-Switching in High Performance Internal Combustion Engines

2020 ◽  
Vol 142 (7) ◽  
Author(s):  
Andrea De Martin ◽  
Giovanni Jacazio ◽  
Massimo Sorli
Keyword(s):  
High Performance ◽  
Internal Combustion Engines ◽  
Internal Combustion ◽  
Operating Conditions ◽  
Valve Lift ◽  
Combustion Engines ◽  
Critical Aspect ◽  
Conceptual Design Phase ◽  
Common Strategy ◽  
Switch System

Abstract The variation of the valve lift is a fairly common strategy currently adopted in several in-service internal combustion engines to optimize their performance depending on the operating conditions of the vehicle. The most critical aspect to consider during the conceptual design phase of a cam switch system is the extremely narrow window of opportunity to perform the cam change, which duration is defined by the time during which the corresponding valve lift is null. To meet this requirement and ensure safe, repeatable movements, a novel architecture based on the combination of a new electromechanical actuator and its dedicated control system is presented. The architecture is at first introduced with reference to the numerous examples available in the literature, and hence mathematically described. The dynamic model of the system derived from the presented equation is then used to study the performance of the presented solution and define its control strategy. Results are finally presented and discussed.

Behavior Prediction Model in Gas Fueled Spark Ignition Internal Combustion Engines Turbocharged for Genset Application

2013 ◽  
Author(s):  
Jorge Duarte Forero ◽  
German Amador Diaz ◽  
Fabio Blanco Castillo ◽  
Lesme Corredor Martinez ◽  
Ricardo Vasquez Padilla
Keyword(s):  
Equivalence Ratio ◽  
Internal Combustion Engines ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Spark Ignition ◽  
Operating Conditions ◽  
Inlet Temperature ◽  
Combustion Engines ◽  
Gaseous Fuels ◽  
Methane Number

In this paper, a mathematical model is performed in order to analyze the effect of the methane number (MN) on knock tendency when spark ignition internal combustion engine operate with gaseous fuels produced from different thermochemical processes. The model was validated with experimental data reported in literature and the results were satisfactory. A general correlation for estimating the autoignition time of gaseous fuels in function of cylinder temperature, and pressure, equivalence ratio and methane number of the fuel was carried out. Livengood and Wu correlation is used to predict autoignition in function of the crank angle. This criterium is a way to predict the autoignition tendency of a fuel/air mixture under engine conditions and consider the ignition delay. A chemical equilibrium model which considers 98 chemical species was used in this research in order to simulate the combustion of the gaseous fuels at differents engine operating conditions. The effect of spark advance, equivalence ratio, methane number (MN), charge (inlet pressure) and inlet temperature (manifold temperature) on engine knocking is evaluated. This work, explore the feasibility of using syngas with low methane number as fuel for commercial internal combustion engines.

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