The impact of maintenance frequency on the service life of internal combustion engines

The service life of thermal engines in transportation and transport-technology machinery determines the efficiency of a wide range of technological operations. Therefore, ensuring high-quality maintenance, considering the operating conditions and intensity of use, is a critical task. This research focuses on analyzing ten years of experience with internal combustion engines in transport divisions of oil and gas production companies. Using the YaMZ-238 engine as an example, it is shown that one of the primary reasons for the reduced mileage before overhaul is untimely maintenance, where the coefficient of variation in maintenance frequency exceeds 0.5. Reducing this value to 0.1 increases the integrated operational reliability and the technical readiness rate of the vehicle fleet by 15 per cent. Consequently, the potential reliability of the engines can be realized through a comprehensive set of measures designed to improve the organization of the maintenance system within the transport divisions of oil and gas production companies

Optimization of the rolling stock service life at transport enterprises

The operation of the rolling stock at transport enterprises is connected with the influence of many factors, and due to their analysis, it is possible to determine the optimal service life of rolling stock to increase the economic efficiency of transport processes. The scientific novelty of the research is represented by the results of experimental data statistical processing that can be used to count the studied patterns models’ parameters for various vehicles and for empirical equations for predicting operating costs based on actual data are established. The practical significance of the obtained results lies in the improvement of technical and economic methods for optimizing the service life of rolling stock based on open information without carrying out resource tests and long-term observations. This makes it possible to assess the operating costs with a high degree of reliability, reasonably form preferences in vehicle configuration and rationally determine the period of effective use, taking into account the type of fuel and the dynamics of changes in the secondary market residual value

The anatomy, physiology, functional significance and evolution of specialized hearing organs of gerbilline rodents

Middle and inner ear anatomy correlates with neurophysiological responses to a wide range of sound frequencies for species of the Gerbillinae representing generalized, intermediate, and specialized anatomical conditions. Neurophysiological data were recorded from 81 specimens of 13 species representing six genera. Anatomical parameters involved in the process of hearing were correlated with the neurophysiological data to assess the effects of different degrees of anatomical specialization on hearing. The 13 species tested in this manner have graphic curves of auditory sensitivity of remarkably similar disposition over the frequencies tested and to those published for Kangaroo Rats. Ears with anatomical specializations show greater auditory sensitivity. The natural history of the Gerbillinae, particularly the kinds of predators, degree of predation, and habitat is reviewed and utilized to interpret the significance of the degree of auditory specialization in the forms studied and to evaluate the prevailing hypothesis that these specializations enhance the ability of these rodents to survive in open desert situations by detecting and evading predators. The middle ear anatomy of five additional genera and species was also studied. Thus, data on the entire spectrum of gerbilline middle ear morphology provide an evolutionary sequence. Certain anatomical parameters of the organ of Corti show a degree of specialization parallel to that of features of the middle ear. The morphological changes and possible functional roles of these features are considered. A very high correlation exists for degree of specialization and aridity of habitat, thus specialization increases with increasing aridity. This increased specialization may result from more effective predation in open xeric environments. Auditory acuity for a wide range of low frequency sounds augmented by auditory specialization is hence more advantageous here. There does not appear to be selection for hearing at particular frequencies in this range. The peaks of greatest auditory sensitivity appear to correspond to the resonant frequencies of the different components of the middle ear transformer and cavity.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/50256/1/1051380103_ftp.pd

Applying the Heaviside step function to simulate the changes of temperature in automotive batteries

Abstract Discharged batteries do not provide the specified voltage in the car’s power supply system during parking, which can cause malfunctions of electrical equipment and an increase in the quiescent current in the on-board network, due to incorrect operation of electronic control units responsible for the operation of self-diagnosis systems, anti-theft alarm, multi-media, maintaining a thermal state, etc. Therefore, to ensure a reliable start of the ICE and the proper operation of the electrical equipment of a car at low temperatures, it is required to maintain the battery in a charged state. Vehicle generator is selected taking into account the nominal capacity of the battery, power and operating modes of electrical consumers, which excludes the battery operation with a low level of charge. However, when operating cars in large cities in winter, the battery charge level decreases. Deterioration of the battery charging characteristics, increased power consumption of additional equipment and low speed of movement of cars in the city with frequent stops at intersections are the reasons for the decrease in the efficiency of the battery charge. In such conditions, the battery can be discharged not only by starting the ICE and turning on consumers in the parking lot, but also when the ICE is idling and at low crankshaft speeds while driving on city routes and during rush hours. Considering that the operational characteristics of the battery change significantly with decreasing temperature, studies aimed at establishing and predicting the battery temperature during operation are relevant.</jats:p

IMPROVING THE EFFICIENCY OF WINTER STUDDED TIRES OPERATION

The aim of the study is to increase the efficiency of vehicle operation by establishing patterns of change in the performance properties of winter tires and improving, on this basis, methods for adjusting the frequency of their replacement. The research methodology is based on the application of a systematic approach, a number of private methods of the experimental-theoretical level and proven methods of processing experimental data. As a result of the analysis of key factors, the relevance of the application of repair technology for studding car tires has been substantiated. Experimental studies on measuring the braking distance and acceleration time have confirmed the need for prompt diagnostics of the residual number of studs on car tires. It was found that the efficiency of the tire as the actual number of studs decreases non-linearly and depends largely on the type of road surface used. The scientific novelty of the performed research is the regularities of braking and acceleration properties of cars operated on various road surfaces in winter conditions, taking into account the technical condition of studded tires. The practical significance of such stands is to increase the demand for this service by reducing costs and significantly reducing labor costs associated with assessing the performance of winter tires. Technological operations using portable stands can be combined with periodic maintenance or carried out with a seasonal tire change both at service stations and in motor transport companies. Further research is aimed at collecting, analyzing and systematizing data to establish the parameters of mathematical models of the most popular standard sizes of automobile winter tires, which will allow scaling the technology and reducing its cost due to mass use. Thus, the results of the on-line diagnostics of tires can be used by car owners when making timely decisions about replacement or repair, which significantly increases traffic safety and reduces the cost of operation, since if the integrity of the tread is preserved, the restoration of winter tires with repair studs almost completely restores the original properties that determine numerical values of efficiency indicators at significantly lower costs in comparison with buying a set of new tires.</jats:p

OPTIMIZATION OF THE ROLLING STOCK SERVICE LIFE AT TRANSPORT ENTERPRISES

The operation of the rolling stock at transport enterprises is connected with the influence of many factors, and due to their analysis, it is possible to determine the optimal service life of rolling stock to increase the economic efficiency of transport processes. The scientific novelty of the research is represented by the results of experimental data statistical processing that can be used to count the studied patterns models’ parameters for various vehicles and for empirical equations for predicting operating costs based on actual data are established. The practical significance of the obtained results lies in the improvement of technical and economic methods for optimizing the service life of rolling stock based on open information without carrying out resource tests and long-term observations. This makes it possible to assess the operating costs with a high degree of reliability, reasonably form preferences in vehicle configuration and rationally determine the period of effective use, taking into account the type of fuel and the dynamics of changes in the secondary market residual value.</jats:p