scholarly journals Experimental Research of Fibrous Materials for Two-Stage Filtration of the Intake Air of Internal Combustion Engines

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7166
Author(s):  
Tadeusz Dziubak ◽  
Leszek Bąkała ◽  
Sebastian Dominik Dziubak ◽  
Kamil Sybilski ◽  
Michał Tomaszewski

Pollutant properties in intake air to internal combustion engines were analyzed. Mineral dust particles’ influence on accelerated engine components’ wear was discussed. Dust concentration values in the air under various operating conditions in trucks and special vehicles were presented. The idea and necessity for using two-stage filters, operating in a “multi-cyclone–porous partition” system for vehicles operated in dusty air conditions, are presented. Information from the literature information has been presented, showing that impurities in small grain sizes reduce fiber bed absorbency. It has been shown that such a phenomenon occurs during filter material operation, located directly behind the inertial filter (multi-cyclone), which off-road vehicles are equipped with. It results in a greater pressure drop intensity increase and a shorter proper filter operation period. It has been shown that filter material selection for the motor vehicle air filter requires knowledge of the mass of stopped dust per filtration unit area (dust absorption coefficient km) determined for a given permissible resistance value Δpfdop. It has been shown that there is no information on absorption coefficient values for filter materials operating in a two-stage “multi-cyclone–porous partition” separation system. Original methodology and conditions for determining dust absorption coefficient (km) of a separation partition, operating under the conditions of two-stage filtration, were presented. The following characteristics were tested: separation efficiency, filtration performance, and pressure drop characteristics of three different filtration partitions. These were A (cellulose), B (cellulose and polyester), and C (cellulose, polyester, and nanofibers layer), working individually and in a two-stage system—behind the cyclone. Granulometric dust composition dosed into the cyclone and cyclone downstream was determined. During tests, conditions corresponding to air filter’s actual operating conditions, including separation speed and dust concentration in the air, were maintained. For the pressure drop values, the dust absorption coefficient (km) values of three different filtration partitions (A, B, and C), working individually and in a two-stage system—behind the cyclone—were determined experimentally.

2021 ◽  
Vol 12 (2) ◽  
pp. 112-121
Author(s):  
Oleksandr Khrulev ◽  
◽  
Olexii Saraiev ◽  
Iryna Saraieva ◽  
◽  
...  

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.


2018 ◽  
Vol 182 ◽  
pp. 01027
Author(s):  
Jan Monieta

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.


2018 ◽  
Vol 20 (4) ◽  
pp. 393-404 ◽  
Author(s):  
José Galindo ◽  
Roberto Navarro ◽  
Luis Miguel García-Cuevas ◽  
Daniel Tarí ◽  
Hadi Tartoussi ◽  
...  

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.


2020 ◽  
Vol 142 (7) ◽  
Author(s):  
Andrea De Martin ◽  
Giovanni Jacazio ◽  
Massimo Sorli

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.


2013 ◽  
Author(s):  
Jorge Duarte Forero ◽  
German Amador Diaz ◽  
Fabio Blanco Castillo ◽  
Lesme Corredor Martinez ◽  
Ricardo Vasquez Padilla

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.


1991 ◽  
Vol 113 (4) ◽  
pp. 511-513 ◽  
Author(s):  
S. A. Klein

Comparisons of the compression ratios, efficiencies, and work of the ideal Otto and Diesel cycles are presented at conditions that yield maximum work per cycle. The compression ratios that maximize the work of the Diesel cycle are found always to be higher than those for the Otto cycle at the same operating conditions, although the thermal efficiencies are nearly identical. The compression ratios that maximize the work of the Otto and Diesel cycles compare well with the compression ratios employed in corresponding production engines.


Author(s):  
Dmytro Borysiuk ◽  
Viacheslav Zelinskyi ◽  
Igor Tverdokhlib ◽  
Yurii Polievoda

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.


2021 ◽  
Author(s):  
Sicong Wu ◽  
Saumil S. Patel ◽  
Muhsin M. Ameen

Abstract Modern internal combustion engines (ICE) operate at the ragged edge of stable operation characterized by high cycle-to-cycle variations (CCV). A key scientific challenge for ICE is the understanding, modeling, and control of CCV in engine performance, which can contribute to partial burns, misfire, and knock. The objective of the current study is to use high-fidelity numerical simulations to improve the understanding of the causes of CCV. Nek5000, a leading high-order spectral element, open source code, is used to simulate the turbulent flow in the engine combustion chamber. Multi-cycle, wall-resolved large-eddy simulations (LES) are performed for the General Motors (GM), Transparent Combustion Chamber (TCC-III) optical engine under motored operating conditions. The mean and root-mean-square (r.m.s.) of the in-cylinder flow fields at various piston positions are validated using PIV measurements during the intake and compression strokes. The large-scale flow structures, including the swirl and tumble flow patterns, are analyzed in detail and the causes for cyclic variabilities in these flow features are explained. The energy distribution across the different scales of the flow are quantified using one-dimensional energy spectra, and the effect of the tumble breakdown process on the energy distribution is examined. The insights from the current study can help us develop improved engine designs with reduced cyclic variabilities in the in-cylinder flow leading to enhanced engine performance.


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