scholarly journals Improvement of maintenance and repair system of internal combustion engines of automotive equipment

2021 ◽  
Vol 341 ◽  
pp. 00062
Author(s):  
Leonid Savin ◽  
Alexander Stetsenko ◽  
Vladimir Panyushkin
Keyword(s):  
Internal Combustion Engines ◽  
Road Transport ◽  
Operating Conditions ◽  
Time Interval ◽  
Repair System ◽  
Time To Failure ◽  
Operation Performance ◽  
Deterministic Models ◽  
Reliability Indicators ◽  
Time Drift

The paper analyzes the operating conditions of road transport affecting its reliability. It is concluded that it is necessary to develop scientifically based strategies flexible of AE maintenance based on predicting the failure moment by extrapolating the process of time drift of the informative parameters of the AE at the interval of its intended use. To solve this problem, we propose an approach based on the use of quasi-deterministic models of the time drift of the AE parameters, which allow to obtain analytical expressions for the main reliability indicators -density of the distribution time to failure and the probability of failure -free operation at a given time interval. On the basis of these indicators of reliability in operation, performance indicators have been formed allowing determining of the optimal maintenance frequency. In the final part of the article, the author proposes an algorithm and a methodology that allows organizing flexible strategies for AE maintenance, considering special conditions of its operation.

scholarly journals TECHNICAL DIRECTIONS OF MAINTENANCE OF WORKING CAPACITY OF ARMOURED VEHICLES OF THE NATIONAL GUARD OF UKRAINE

2021 ◽  
Vol 1 (37) ◽  
pp. 89-95
Author(s):  
I. Shasha ◽  
Keyword(s):  
National Guard ◽  
Road Transport ◽  
Operating Conditions ◽  
Repair System ◽  
System State ◽  
Working Capacity ◽  
Territorial Defence ◽  
Maintenance And Repair ◽  
Special Operations ◽  
Design And Manufacture

Maintenance of armoured vehicles in modern conditions has a significant impact on the effectiveness of combat missions. In particular, the timeliness of delivery of personnel and necessary cargo can be a critical parameter for the success of tasks in emergencies of man-made and natural origin, riots, participation in special operations for searching for and neutralizing armed criminals, eliminating illegal armed groups or performing territorial defence tasks. A complex characteristic of any technical system is its efficiency as a measure of the feasibility of solutions adapted to operating conditions. Assessing the effectiveness of armoured vehicles is associated with the need to predict performance, which directly depends on the application of modern technical areas to maintain the required level of performance. The efficiency of the system - the ability to perform its functions with a certain level of quality during the established period of operation. The efficiency of the system is determined by the set of its properties, laid down in the design and manufacture and maintained during operation. In this work, the criterion of effectiveness is to maintain the efficiency of armoured vehicles at the required level in service and combat use in a variety of road, transport and atmospheric-climatic operating conditions. Strategies and tactics for maintaining armoured vehicles performance at the required level are considered. The specificity of the operation of armoured vehicles is that it is used in different, sometimes very difficult conditions. Therefore, an individual approach is required, an adaptive maintenance and repair system state of armoured vehicles. The most expedient for armoured vehicles is a balanced combination of all levels of regulation of the systems of organization of maintenance and repair.

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 Theoretical Approach to Estimating the Probabilities of Trouble-free Operation of Transport and Production Systems and Supply Chains Based on Their Logical Structural Schemes of Reliability

2020 ◽  
pp. 290-304
Author(s):  
Vktor Aulin ◽  
◽  
Dmytro Holub ◽  
Sergiy Lisenko ◽  
Andriy Grinkiv ◽  
...  
Keyword(s):  
Transport System ◽  
Cross Sections ◽  
Structural Reliability ◽  
Production Systems ◽  
Road Transport ◽  
Probability Of Failure ◽  
Reliability Estimation ◽  
Transport Systems ◽  
Time To Failure ◽  
Reliability Indicators

The purpose of the work is to develop a method of estimating the probability of failure-free operation of transport systems on the basis of their logical structural diagrams of reliability, which makes it possible to evaluate their dependence on the level of probability and the number of elements and to predict and prevent failure of a chain or system as a whole. The theoretical substantiation of reliability estimation of functioning of transport systems using logical structural schemes of reliability is given and it is revealed that their construction is based on the analysis of consequences of failures of individual elements. Properties of elements and systems for their working and inoperable states are highlighted. The formulas for calculating the probability of failure-free operation and failure of the chain or the transport system as a whole, as well as their time to failure. The dependence of the probability of failure-free operation of the transport system on the level of probability and the number of its elements is shown. Cases of serial and parallel connection of elements in the transport system chain are considered. Methods of calculation of structural reliability schemes are presented and formulas are used for estimating the probability of trouble-free operation of technical and transport systems, as well as the probability of their failures. Dependencies of reliability indicators on number of elements are constructed. It shows the reliability estimation of bridged structural diagrams using the methods of minimum paths, minimum cross sections, transformation of the connection of elements "triangle" - "asterisk", a key element. It is found that complex technical and transport systems have a large number of elements, and therefore the reliability of such systems depends not only on the reliability of the individual elements, but also on the nature of the connections between them. Carrying out the reliability analysis of transport systems is possible with the help of their structural functional circuits of reliability and unlike physical circuits that reproduce physical connections between elements, logical reliability circuits are built to show what combinations of failures of individual elements of the system lead to failure of a circuit or system in general. Thus, the construction of logical reliability schemes is based on the analysis of the consequences of the causes of failures of individual elements, which can later be used in the development of theoretical bases for improving the reliability of the functioning of road transport systems.

Experimental Evaluation of Turbo-Matching Appropriateness of B60J67, B60J68, A58N70 and A58N72 Turbo-Chargers for a Commercial Vehicle Engine

2018 ◽  
Vol 6 (11) ◽  
pp. 71
Author(s):  
Badal Dev Roy ◽  
R. Saravanan
Keyword(s):  
Internal Combustion Engines ◽  
Perfect Match ◽  
Engine Performance ◽  
Operating Conditions ◽  
Data Logger ◽  
Negative Effects ◽  
Road Test ◽  
The Road ◽  
A Charge ◽  
All Speeds

The Turbocharger is a charge booster for internal combustion engines to ensure best engine performance at all speeds and road conditions especially at the higher load.  Random selection of turbocharger may lead to negative effects like surge and choke in the breathing of the engine. Appropriate selection or match of the turbocharger (Turbomatching) is a tedious task and expensive. But perfect match gives many distinguished advantages and it is a one time task per the engine kind. This study focuses to match the turbocharger to desired engine by simulation and on road test. The objective of work is to find the appropriateness of matching of turbochargers with trim 67 (B60J67), trim 68 (B60J68),  trim 70 (A58N70) and trim 72 (A58N72) for the TATA 497 TCIC -BS III engine. In the road-test (data-logger method) the road routes like highway and slope up were considered for evaluation. The operating conditions with respect various speeds, routes and simulated outputs were compared with the help of compressor map.

ASSESSMENT OF THE RELIABILITY OF VACUUM PRECISION PIEZOELECTRIC RESONATORS ACCORDING TO THE RESULTS OF THE ACCUMULATION AND COMPILATION OF THEIR LIFE CYCLE

2018 ◽  
pp. 65-71 ◽  
Author(s):  
I. V. Arkhipova
Keyword(s):  
Life Cycle ◽  
Reliability Theory ◽  
Time To Failure ◽  
Bayesian Theorem ◽  
Piezoelectric Resonators ◽  
Reliability Indicators ◽  
Performance Requirements ◽  
Methodical Basis ◽  
New Ideas ◽  
Generalization Of Data

Within the framework of this article the question of reliability evaluation of resonators with strict performance requirements for resistance to external factors is considered. Due to the increase in requirements for these products in terms of gamma-percentile time to failure and gamma-percentile storageability time, there is a need to develop new ideas and methods of reliability theory. As a methodical basis for generalization of data of their life cycle the approach on the basis of Bayesian theorem is offered. Based on the results of generalization of the statistics of resonator tests for various types of climatic influences and reliability tests, as well as the results of their use in the electronic equipment have been identified their main reliability indicators.

scholarly journals A Comparative Study of Biofuels and Fischer–Tropsch Diesel Blends on the Engine Combustion Performance for Reducing Exhaust Gaseous and Particulate Emissions

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1538
Author(s):  
Felipe Andrade Torres ◽  
Omid Doustdar ◽  
Jose Martin Herreros ◽  
Runzhao Li ◽  
Robert Poku ◽  
...  
Keyword(s):  
Diesel Fuel ◽  
Alternative Fuels ◽  
Internal Combustion Engines ◽  
Road Transport ◽  
Oxidation Catalyst ◽  
Transport Sector ◽  
Particulate Emissions ◽  
Gaseous Emissions ◽  
Fischer Tropsch ◽  
Engine Combustion

The worldwide consumption of fossil hydrocarbons in the road transport sector in 2020 corresponded to roughly half of the overall consumption. However, biofuels have been discreetly contributing to mitigate gaseous emissions and participating in sustainable development, and thus leading to the extending of the commercial utilization of internal combustion engines. In this scenario, the present work aims at exploring the effects of alternative fuels containing a blend of 15% ethanol and 35% biodiesel with a 50% fossil diesel (E15D50B35) or 50% Fischer–Tropsch (F-T) diesel (E15FTD50B35) on the engine combustion, exhaust emissions (CO, HC, and NOx), particulate emissions characteristics as well as the performance of an aftertreatment system of a common rail diesel engine. It was found that one of the blends (E15FTD50B35) showed more than 30% reduction in PM concentration number, more than 25% reduction in mean particle size, and more than 85% reduction in total PM mass with respect to conventional diesel fuel. Additionally, it was found that the E15FTD50B35 blend reduces gaseous emissions of total hydrocarbons (THC) by more than 25% and NO by 3.8%. The oxidation catalyst was effective in carbonaceous emissions reduction, despite the catalyst light-off being slightly delayed in comparison to diesel fuel blends.

Investigating realistic anode off-gas combustion in SOFC/ICE hybrid systems: mini review and experimental evaluation

2021 ◽  
pp. 146808742110583
Author(s):  
Ioannis Nikiforakis ◽  
Zhongnan Ran ◽  
Michael Sprengel ◽  
John Brackett ◽  
Guy Babbit ◽  
...  
Keyword(s):  
Thermal Efficiency ◽  
Internal Combustion Engines ◽  
Engine Performance ◽  
High Energy ◽  
Operating Conditions ◽  
Compression Ignition ◽  
Case Scenario ◽  
Gas Combustion ◽  
Thermodynamic Conditions ◽  
Decentralized Energy

Solid oxide fuel cells (SOFCs) have been deployed in hybrid decentralized energy systems, in which they are directly coupled to internal combustion engines (ICEs). Prior research indicated that the anode tailgas exiting the SOFC stack should be additionally exploited due to its high energy value, with typical ICE operation favoring hybridization due to matching thermodynamic conditions during operation. Consequently, extensive research has been performed, in which engines are positioned downstream the SOFC subsystem, operating in several modes of combustion, with the most prevalent being homogeneous compression ignition (HCCI) and spark ignition (SI). Experiments were performed in a 3-cylinder ICE operating in the latter modus operandi, where the anode tailgas was assimilated by mixing syngas (H2: 33.9%, CO: 15.6%, CO2: 50.5%) with three different water vapor flowrates in the engine’s intake. While increased vapor content significantly undermined engine performance, brake thermal efficiency (BTE) surpassed 34% in the best case scenario, which outperformed the majority of engines operating under similar operating conditions, as determined from the conducted literature review. Nevertheless, the best performing application was identified operating under HCCI, in which diesel reformates assimilating SOFC anode tailgas, fueled a heavy duty ICE (17:1), and gross indicated thermal efficiency ([Formula: see text]) of 48.8% was achieved, with the same engine exhibiting identical performance when operating in reactivity-controlled compression ignition (RCCI). Overall, emissions in terms of NOx and CO were minimal, especially in SI engines, while unburned hydrocarbons (UHC) were non-existent due to the absence of hydrocarbons in the assessed reformates.

Life Prediction of Directionally Solidified Air Cooled HPT Gas Turbine Blade Used in a Supersonic Aircraft Using FEM

2013 ◽  
Author(s):  
S. Esakki Muthu ◽  
S. Dileep ◽  
S. Saji Kumar ◽  
D. K. Girish
Keyword(s):  
Gas Turbine ◽  
Turbine Blade ◽  
Operating Conditions ◽  
Test Facility ◽  
Time To Failure ◽  
Generation Process ◽  
Gas Turbine Blade ◽  
Directionally Solidified ◽  
Life Estimation ◽  
Supersonic Aircraft

Life estimation of Directionally Solidified (DS) MARM-247 HPT gas turbine blade used in a turbofan engine of a supersonic aircraft is presented. These blades were drafted into the engine as a replacement for the polycrystal (NIMONIC) blades since a more efficient, reliable and durable material with high strength and temperature resistance was required to further enhance the life of the turbine blade and the efficiency of the power generation process. The supersonic aircraft is having a repeated mission cycle of a fast acceleration from idle, a 1hr cruise at Mach 1.5 and a fast deceleration to idle. The mission cycle which is a repetition of acceleration, cruise and deceleration cycles can produce wide variety of complex loading conditions which can result in HCF, LCF and creep damage of the turbine blade. Empirical equation of the universal slope developed by Manson was used to estimate the damage component due to LCF. The cumulative stresses and strains due to creep as a function of time was determined using Time hardening rule. Creep data for MARM-247 was correlated using LMP to predict the lives to 1% of creep strain at worst possible combination of temperature and stress value. Damage due to creep per mission cycle was determined using Life fraction Rule proposed by Robinson and Taira. The vibration characteristics of the turbine blade were predicted using Modal analysis. Campbell diagram was plotted to ascertain whether any nozzle passing frequency fall within the working range of the blade. Harmonic analysis was carried out to evaluate the magnitude of the alternating stresses resulting from the blade vibrations at resonance during the acceleration and deceleration cycle. HCF life of the turbine blade was assessed using Goodman diagram. The total damage of the turbine blade per mission cycle due to the above loading was assumed as the combination of the individual damage due to fatigue and creep. Time to failure under combined creep and fatigue damage was estimated using linear damage rule. Non linear features of FEA tool ANSYS12.0 was exploited to calculate the stress distribution, creep, plastic and the total strain encountered by the turbine blade as a function of mission cycle time. The loading spectrum associated with the mission cycle which includes the temperature, gas pressure and the speed profiles were obtained from a sophisticated engine ground test facility which was configured to simulate actual engine operating conditions. The proposed method of cyclic life estimation using FEM was validated by performing various component and engine level tests. A good agreement was observed between the calculated and observed blade lives.

Double Scroll Turbine for Automotive Applications: Engine Operating Point Versus Dynamic Blade Stress From Forced Response Vibration

2018 ◽  
Author(s):  
David Hemberger ◽  
Roberto De Santis ◽  
Dietmar Filsinger
Keyword(s):  
Pulse Energy ◽  
Internal Combustion Engines ◽  
Forced Response ◽  
Operating Conditions ◽  
Blade Vibration ◽  
Structural Dynamic ◽  
Vibration Excitation ◽  
Engine Combustion ◽  
Operating Points ◽  
Combustion Cycle

As a means of meeting ever increasing emissions and fuel economy demands car manufacturers are using aggressive engine downsizing. To maintain the power output of the engine turbocharging is typically used. Compared to Mono scroll turbines, with a multi-entry system the individual volute sizing can be better matched to the single mass flow pulse from the engine cylinders. The exhaust pulse energy can be better utilised by the turbocharger turbine improving turbocharger response. Additionally the interaction of the engine exhaust pulses can be better avoided, improving the scavenging of the engine. Besides the thermodynamic advantages, the multi-entry turbine represents a challenge to the structural dynamic design of the turbine. A higher number of turbine wheel resonance points can be expected during operation. In addition, the increased use of exhaust pulse energy leads to a distinct accentuation of the blade vibration excitation. Using validated engine models, the interaction of the multi-entry turbine with the engine has been analyzed and various operating points, which may be critical for the blade vibration excitation, have been classified. These operating points deliver the input variables for unsteady computational flow dynamics (CFD) analyses. From these calculations unsteady blade forces were derived providing the necessary boundary conditions for the structural dynamic analyses by spatially and temporally high-resolved absolute pressures on the turbine surface. Goal of the investigation is to identify critical operating conditions. Important is also to investigate the effect of a scroll connection valve on blade excitation. The investigations utilize validated tools that were introduced and successfully applied to several turbine types in a series of publications over recent years. It can be stated that the engine operating condition and the admission type significantly influence the forced response reaction of the blade to the different excitation orders (EO). In case of equal admission even (or multiples of two) EOs generate the largest dynamic blade stress as can be expected due to the two turbine inlet segments. This reaction also increases with the engine speed. In the case of unequal admission, the odd EOs produce the largest forced response reaction. The maximum dynamic blade stress occurs in the region where the scroll connection is just closed. Above all, the scroll connection valve influences the Beta value and thus the basic behavior — unequal or equal admission. It has been possible to reconstruct the forced response behavior of the turbine blade within an engine combustion cycle. For the first time it could be shown for a double scroll application that there is a significant dynamic blade stress change dependent on the engine crankshaft angle. Certainly, due to the inertia of the mass and damping (mass, structure, flow), the blade will not exactly follow the predicted course. However, it is clear that the transient processes within an engine combustion cycle will affect the dynamic blade stress. This applies to the turbine wheels investigated in the work at hand with low damping, high eigenfrequencies and the considered internal combustion engines — as they are typically used in the passenger car sector.

scholarly journals ON IMPROVEMENT OF ENVIRONMENTAL INDICATORS OF THE KHARKIV MOTORWAY SECTION

2021 ◽  
Vol 6 (166) ◽  
pp. 196-203
Author(s):  
E. Lezhneva ◽  
I. Lynnyk ◽  
K. Vakulenko ◽  
N. Sokolova
Keyword(s):  
Noise Level ◽  
Internal Combustion Engines ◽  
Road Transport ◽  
Environmental Indicators ◽  
Sound Waves ◽  
Solar Panels ◽  
Residential Areas ◽  
Noise Levels ◽  
Large Cities ◽  
Main Area

Nowadays, on the territory of large cities, there is an increase in emissions of harmful substances into the atmosphere. The reasons for this are manifold: violation of design technological regimes, outdated equipment, an increase in the volume of road transport. The constantly growing intensity of traffic flows is annually accompanied by an increase in the anthropogenic load on the population of modern cities. With the increase in the number of vehicles on the streets of large cities, the world community has identified noise as one of the main factors that worsen the standard of living of people. To assess the noise pollution of the environment by road transport, a typical area of the urban area in the Kharkiv micro district was chosen. The study consisted of four main stages: Stage I – assessment of the road condition and environmental situation in the courtyards of the micro district; Stage II – assessment of acoustic pollution of the main area; Stage III – assessment of the concentration of pollutants; Stage IV – measures to reduce the level of environmental hazard. The study revealed that residential areas around Gagarin Avenue are prone to high noise levels and high concentrations of pollutants in the air. So, Gagarin Avenue is in the zone of acoustic discomfort (noise level 80 dBA), which exceeds the permissible noise level, while the degree of man-made impact on the environment during road operation is 1000 UAH / hour for every 100 people. Based on the results of calculations of the concentrations of pollutants from vehicles along Gagarin Avenue, it was found that for almost all substances their concentrations exceed the MPC by more than 3 times. Analysis of the experience of European countries in the use of noise protection screens with integrated solar panels allowed us to propose a model of noise protection barrier with integrated solar panels, which can be used to protect the urban environment from noise, sound waves and exhaust chemicals. gases from internal combustion engines. It has been established that the placement of a combined noise protection screen will reduce the noise level by about 8–15 dBA. Noise load maps were built in the main area before and after the implementation of the environmental measure. The results of the study will make it possible to introduce administrative and legislative measures to ensure regulatory noise levels for residential areas adjacent to highways and environmental safety when organizing traffic on the streets of large cities.

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