scholarly journals Estimating efficiency of forecasting technical conditions of ship propulsion systems

2021 ◽  
Vol 2021 (4) ◽  
pp. 27-33
Author(s):  
Guriy Alekseevich Kushner ◽  
Victor Andreevich Mamontov
Keyword(s):  
Service Life ◽  
Operating Conditions ◽  
Technical State ◽  
Extrapolation Method ◽  
Normal Operation ◽  
Propeller Shaft ◽  
Shaft Line ◽  
Operating Modes ◽  
Forecasting System ◽  
Vibration Parameters

The article considers an approach to assessing the effectiveness of the most common methods of predicting the technical conditions and failure with reference to the ship shafting. There have been analyzed the main factors in operation of the ship shaft line, which cause the change in its technical state. It has been found that a special feature of some loads acting on the propeller shaft is their stochastic or changing nature over time, which hampers predicting the technical state of the shafting and its units. The features of stochastic and extrapolation forecasting methods have been analyzed. The possibility of using statistical methods in conditions of mass standard production of shafting units with a relatively short regulated service life is estimated. An extrapolation method is proposed for predicting the maximum permissible clearance of stern tube bearings. The case of accumulating samples of measuring results of the propeller shaft sagging in the given time intervals is considered, the approximating functions are constructed. The criteria for the reliability of the results of extrapolation methods for predicting the wear of stern tube bearings are determined. There have been developed the proposals for adapting the causal method as an alternative to the extrapolation method. A schematic diagram of a system for the ship shafting failure predicting has been developed using the registration and analysis of vibration parameters, which serves as the basis for constructing a regression model of damage accumulation. The proposed forecasting system allows studying the actual operating conditions of the shafting, defining the actual external loads and the regularities of their occurrence, measuring deformations and stresses, and determining quantitative indicators of the reliability of the shafting during normal operation and special operating modes, for example, with vibration resonance. The theoretical basis of the algorithm for calculating and registering loads affecting the service life of shafts is proposed.

scholarly journals USING OF THE MATHEMATICAL APPARATUS REGRESSION ANALYSIS TO UNIFY THE CALCULATING METHODOLOGY FOR THE T-64B TANK'S OVERHAUL LIFE

2021 ◽  
Vol 5 (3) ◽  
pp. 151-157
Author(s):  
Helen Makogon ◽  
Volodymyr Chalapko ◽  
Serhiy Guba ◽  
Vladyslav Staryshenko ◽  
Viktor Moskalenko ◽  
...  
Keyword(s):  
Life Cycle ◽  
Service Life ◽  
Training Group ◽  
Regression Equation ◽  
Operating Conditions ◽  
Analytical Dependence ◽  
Normal Operation ◽  
Mathematical Apparatus ◽  
Repair Service ◽  
Combat Training

The subject matter of the article is the life cycle of a T-64B tank sample during the period from normal operation in a combat training group to resource consumption and carrying out average and capital repairs. The goal of the study is to develop a model of dependence of inter-repair service life of the T-64B tank sample on the machine operating conditions and, on its basis, a methodology for controlling the parameters of individual assemblies and systems of the tank sample during its life cycle. The tasks to be solved are: to analyze the results of statistical records of tank system failures and damages number and identify the predicates set affect the inter-repair service life of the machine depending on conditions of its tasks for the intended purposes; to create the regression equation for getting the unified analytical dependence of inter-repair service life of the T-64B tank sample in the period from normal operation in training and combat group to service life and overhaul; to investigate specific influence of reliability indices on the machine's service life. General scientific and special methods of scientific knowledge are used. The method of hierarchy analysis, mathematical apparatus of probability theory and multidimensional statistical analysis were used. The following results are obtained. A set of predicates influence the inter-repair service life of the machine depending on conditions of its tasks for the intended purposes fulfillment has been determined. A regression equation has been drawn up to obtain a unified analytical dependence of the overhaul life of a T-64B tank sample during the period from normal operation in a combat training group to the development of a resource and carrying out of intermediate and complete overhauls were drawn up. Engineering solutions have been proposed to implement a methodology for monitoring the parameters of individual units and systems of the tank sample during its life cycle, namely integrated real-time monitoring of oil condition and recording of engine operating hours under various load conditions. Conclusions. The space of features characterizes the conditions of the tank sample tasks for its intended purposes, includes service life, crew training, operation, seasonality of the unit’s performed tasks nature, machine  operating time since the last service and range of the vehicle before the next overhaul. The analytical relationship between the individual factors determining the conditions under which the T-64B tank sample performs its tasks for the intended purposes and the machine's service life consumption as a dependent variable can be determined in the form of a regression equation. Differentiated control of the parameters of individual assembly units and systems of the tank sample plays a leading role in ensuring the combat readiness and efficiency of the use of aging samples of weapons, insures personnel against possible accidents and catastrophes, sudden failures.

scholarly journals Degradation of Lithium-Ion Batteries in an Electric Transport Complex

Energies ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 8072
Author(s):  
Nickolay I. Shchurov ◽  
Sergey I. Dedov ◽  
Boris V. Malozyomov ◽  
Alexander A. Shtang ◽  
Nikita V. Martyushev ◽  
...  
Keyword(s):  
Service Life ◽  
Lithium Ion Batteries ◽  
Residual Life ◽  
Technical Problem ◽  
Lithium Ion ◽  
Operating Conditions ◽  
Battery Management ◽  
Electric Transport ◽  
Operating Modes ◽  
Number Of Cycles

The article provides an overview and comparative analysis of various types of batteries, including the most modern type—lithium-ion batteries. Currently, lithium-ion batteries (LIB) are widely used in electrical complexes and systems, including as a traction battery for electric vehicles. Increasing the service life of the storage devices used today is an important scientific and technical problem due to their rapid wear and tear and high cost. This article discusses the main approaches and methods for researching the LIB resource. First of all, a detailed analysis of the causes of degradation was carried out and the processes occurring in lithium-ion batteries during charging, discharging, resting and difficult operating conditions were established. Then, the main factors influencing the service life are determined: charging and discharging currents, self-discharge current, temperature, number of cycles, discharge depth, operating range of charge level, etc. when simulating a real motion process. The work considers the battery management systems (BMS) that take into account and compensate for the influence of the factors considered. In the conclusion, the positive and negative characteristics of the presented methods of scientific research of the residual life of LIB are given and recommendations are given for the choice of practical solutions to engineers and designers of batteries. The work also analyzed various operating cycles of electric transport, including heavy forced modes, extreme operating modes (when the amount of discharge and discharge of batteries is greater than the nominal value) and their effect on the degradation of lithium-ion batteries.

Distributed Modeling Of Building Systems Through Cyber-Physical Integration

2019 ◽  
pp. 12-17
Keyword(s):  
Data Structure ◽  
Operating Conditions ◽  
Physical Models ◽  
Distributed Model ◽  
Physical Processes ◽  
Distributed Modeling ◽  
Distributed Models ◽  
Operating Modes ◽  
Building Systems ◽  
Important Practical Application

This article describes the proposed approaches to creating distributed models that can, with given accuracy under given restrictions, replace classical physical models for construction objects. The ability to implement the proposed approaches is a consequence of the cyber-physical integration of building systems. The principles of forming the data structure of designed objects and distributed models, which make it possible to uniquely identify the elements and increase the level of detail of such a model, are presented. The data structure diagram of distributed modeling includes, among other things, the level of formation and transmission of signals about physical processes inside cyber-physical building systems. An enlarged algorithm for creating the structure of the distributed model which describes the process of developing a data structure, formalizing requirements for the parameters of a design object and its operating modes (including normal operating conditions and extreme conditions, including natural disasters) and selecting objects for a complete group that provides distributed modeling is presented. The article formulates the main approaches to the implementation of an important practical application of the cyber-physical integration of building systems - the possibility of forming distributed physical models of designed construction objects and the directions of further research are outlined.

Viability of turbine blade material with a long service life

2019 ◽  
pp. 28-35
Author(s):  
O. B. Berdnik ◽  
I. N. Tsareva ◽  
M. K. Chegurov
Keyword(s):  
Heat Treatment ◽  
Service Life ◽  
Yield Strength ◽  
Mechanical Characteristics ◽  
Operating Time ◽  
Structural Features ◽  
Operating Conditions ◽  
Standard Methods ◽  
Experimental Values ◽  
Plasticity Coefficient

This article deals with structural features and characteristic changes that affect the mechanical characteristics after different service life in real conditions using the example of the blades of the 4th stage of turbine GTE-45-3 with an operating time of 13,000 to 100,000 hours. To study the change in the state of the material under different operating conditions, determine the degree of influence of heat treatment on the regeneration of the microstructure, and restore the mechanical characteristics of the alloy after different periods of operation, non-standard methods were used: relaxation tests on miniature samples to determine the physical yield strength and microplasticity limit and quantitative evaluation of the plasticity coefficient of the material from experimental values of hardness, which allow us to identify the changes occurring in the microvolumes of the material and predict the performance of the product as a whole.

scholarly journals Octane Index Applicability over the Pressure-Temperature Domain

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 607
Author(s):  
Tommy R. Powell ◽  
James P. Szybist ◽  
Flavio Dal Forno Chuahy ◽  
Scott J. Curran ◽  
John Mengwasser ◽  
...  
Keyword(s):  
High Efficiency ◽  
National Laboratory ◽  
Operating Conditions ◽  
Dominant Factor ◽  
Compression Ignition ◽  
Oak Ridge ◽  
Operating Modes ◽  
Wide Range ◽  
Thermodynamic Conditions ◽  
Si Engines

Modern boosted spark-ignition (SI) engines and emerging advanced compression ignition (ACI) engines operate under conditions that deviate substantially from the conditions of conventional autoignition metrics, namely the research and motor octane numbers (RON and MON). The octane index (OI) is an emerging autoignition metric based on RON and MON which was developed to better describe fuel knock resistance over a broader range of engine conditions. Prior research at Oak Ridge National Laboratory (ORNL) identified that OI performs reasonably well under stoichiometric boosted conditions, but inconsistencies exist in the ability of OI to predict autoignition behavior under ACI strategies. Instead, the autoignition behavior under ACI operation was found to correlate more closely to fuel composition, suggesting fuel chemistry differences that are insensitive to the conditions of the RON and MON tests may become the dominant factor under these high efficiency operating conditions. This investigation builds on earlier work to study autoignition behavior over six pressure-temperature (PT) trajectories that correspond to a wide range of operating conditions, including boosted SI operation, partial fuel stratification (PFS), and spark-assisted compression ignition (SACI). A total of 12 different fuels were investigated, including the Co-Optima core fuels and five fuels that represent refinery-relevant blending streams. It was found that, for the ACI operating modes investigated here, the low temperature reactions dominate reactivity, similar to boosted SI operating conditions because their PT trajectories lay close to the RON trajectory. Additionally, the OI metric was found to adequately predict autoignition resistance over the PT domain, for the ACI conditions investigated here, and for fuels from different chemical families. This finding is in contrast with the prior study using a different type of ACI operation with different thermodynamic conditions, specifically a significantly higher temperature at the start of compression, illustrating that fuel response depends highly on the ACI strategy being used.

scholarly journals Analysis of vibrodiagnostics methods in the technical state study of designed multimedia mobile scenes

2019 ◽  
Vol 302 ◽  
pp. 01011
Author(s):  
Marcin Łukasiewicz ◽  
Michał Liss ◽  
Natalia Dluhunovych
Keyword(s):  
Modal Analysis ◽  
Diagnostic Tests ◽  
Research Process ◽  
Technical Condition ◽  
Technical State ◽  
Normal Operation ◽  
Design Stage ◽  
Analysis Methods ◽  
State Study ◽  
Diagnostic Research

The paper presents the possibilities of using vibroacoustic methods in the study of the technical condition of designed multimedia mobile scenes. In particular, the possibility of implementing modal analysis methods in modelling and diagnostic research process has been presented. The use of virtual methods enables diagnostic tests both at the design stage and at the stage of normal operation, whereas modal methods help to explain the nature of the work of the element under investigation.

scholarly journals Predicting the influence of the non-sinusoidal network mode on power transformers

2019 ◽  
Vol 114 ◽  
pp. 04005
Author(s):  
Ngo Van Cuong ◽  
Lidiia I. Kovernikova
Keyword(s):  
Service Life ◽  
Electric Power ◽  
Power Quality ◽  
Electrical Equipment ◽  
Operating Conditions ◽  
Transformer Oil ◽  
Power Transformers ◽  
Electrical Network ◽  
Electrical Networks ◽  
Current Harmonics

The parameters of electrical network modes often do not meet the requirements of Russian GOST 32144-2013 and the guidelines of Vietnam. In the actual operating conditions while there is the non-sinusoidal mode in electrical networks voltage and current harmonics are present. Harmonics result in overheating and damage of power transformers since they cause additional active power losses. Additional losses lead to the additional heat release, accelerating the process of insulating paper, transformer oil and magnetic structure deterioration consequently shortening the service life of a power transformer. In this regard there arises a need to develop certain scientific methods that would help demonstrate that low power quality, for instance could lead to a decrease in the electrical equipment service life. Currently we see a development of automated systems for continuous monitoring of power quality indices and mode parameters of electrical networks. These systems could be supplemented by characteristics calculating programs that give out a warning upon detection of the adverse influence of voltage and current harmonics on various electrical equipment of both electric power providers and electric power consumers. A software program presented in the article may be used to predict the influence of voltage and current harmonics on power transformers.

Time-domain extrapolation method for tractor drive shaft loads in stationary operating conditions

2021 ◽  
Vol 210 ◽  
pp. 143-155
Author(s):  
Zihan Yang ◽  
Zhenghe Song ◽  
Xueyan Zhao ◽  
Xingxiang Zhou
Keyword(s):  
Time Domain ◽  
Operating Conditions ◽  
Drive Shaft ◽  
Extrapolation Method

Experimental testing of open pit dump trucks in operating conditions

2020 ◽  
pp. 530-542
Author(s):  
A. G. Zhuravlev ◽  
M. V. Isakov
Keyword(s):  
Power Plants ◽  
Experimental Testing ◽  
Operating Conditions ◽  
Open Pit ◽  
Dump Truck ◽  
Experimental Measurements ◽  
Complex Data ◽  
Special Unit ◽  
Operating Modes ◽  
Dump Trucks

The high importance of optimizing the operation of quarry transport is confirmed by the leading share of its costs in the total cost of mining. The current direction of optimization is the development and implementation of digital technologies for processing complex data on the parameters of transport vehicles. The solution of the above issues should be based on the results of scientific research on the collection and processing of information. Developed a set of techniques to perform experimental measurements of working parameters of mining dump trucks as part of a special unit experiments, and long monitoring measurements. A set of equipment for performing experimental measurements, as well as its installation on a dump truck is presented. The data of experimental measurements and a methodical approach to their analysis are presented. In particular, it shows the identification of operating modes of the power plant and the construction of the load diagram, the identification of elements of the transport cycle, etc. The approach to substantiation of innovative designs of power plants adapted to the conditions of a particular quarry is shown on the example of calculated schedules of energy consumption and reserve of recovery of braking energy. The proposed hardware-methodical complex is a research model for the development of methods for automated data collection and processing in the formation of elements of digital mining production.

IMPROVEMENT OF THE PROCESS OF OPERATION OF THE GUIDE MOVING CROSSBARS OF HYDRAULIC PRESSES

2020 ◽  
Author(s):  
K.O. Kobzev ◽  
◽  
S.A. Vyalov ◽  
E.S. Bozhko ◽  
I.A. Zolotuhina ◽  
...  
Keyword(s):  
Service Life ◽  
Hydraulic Press ◽  
Operating Conditions ◽  
The Press ◽  
Technical Solutions

This article deals with the problem of operating conditions of guide moving crossbars of hydraulic presses. Based on the study of hydraulic press operation processes, the need to develop and implement measures to ensure reliable and trouble-free operation of the press was identified. The conclusion justifies the idea that if these technical solutions are implemented, the service life of hydraulic presses will increase

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