Model Of Working Process Research Articles

IMPLEMENTATION OF HIGHLY EFFICIENT THERMODYNAMIC CYCLES IN TWO-STROKE SOLID-FUEL PISTON INTERNAL COMBUSTION ENGINES OF SHIP PURPOSE

An analysis of global fuel resources indicates that the most common fossil fuels on earth are solid fuels. Experts believe that while maintaining the current pace of their use, coal reserves will be enough for at least another 400...450 years. The low price of this type of fuel makes their use an attractive prospect for use as engine fuel for internal combustion engines. Attempts to create engines capable of working on solid fuels have been made throughout the entire period of the ICE's existence, starting with the work of R. Diesel to create its rational engine. However, throughout this period, the main efforts of specialists were aimed at adapting existing types of piston engines operating on liquid or gaseous fuels for the use of coal fuel in the form of fine dust directly supplied to the working cylinder, or injected into the combustion chamber in composition of a fuel or water-coal suspension. The first attempt to develop an engine that was specially created for the use of solid fuels and which would maximize the advantages of their state of aggregation was the work of the American engineer Joseph C. Firey, who proposed a design with in-cylinder gasification of solid fuel. Subsequently, the authors have improved this method by organizing a forced purge of a layer of solid fuel in the process of supplying heat to the working medium. The authors have developed and implemented a numerical model of this engine working process, using which a number of studies were carried out aimed at finding new approaches to the organization of working processes in solid-fuel engines with layered combustion, which allow the maximum use of the features of preparing an air charge for combustion and a controlled heat supply process to increase the thermodynamic efficiency of the workflow. This article is devoted to the discussion of the results of this study.

Анализ энергетических характеристик безмасляного спирального вакуумного насоса

This paper presents an analysis of the indicator power of an oil-free scroll vacuum pump based on the indicator diagrams obtained through high-speed pressure sensors. These values are compared with the results of calculations using a mathematical model of the pump working process. It is shown that the divergence of the calculated results and experimental values does not exceed 4%, which confirms the adequacy of the developed mathematical model. The total power of the scroll pump exceeds the indicator power by more than 2 times due to the friction losses between the face seals and disks of the reciprocal scroll elements, friction losses in the stuffing box seals and rolling bearings, as well as due to the coefficient of efficiency of the motor. The influence of the radial clearance between the scroll elements on the power consumption is considered. It is shown that at low pressures nearing the ultimate pressure, the power increases with the increased clearance, while at inlet pressures exceeding 40 kPa it decreases. The performed analysis can be used for selecting the optimal geometrical parameters of the scroll elements and increasing power efficiency of the pump depending on specific operating conditions.

Analysis and Optimisation of Thermo-Mechanical Coupling Load of Cylinder Head Considering Fluid-Structure Interaction for a Marine High-Power Diesel Engine

A one-dimensional model of the diesel engine working process was established, and thermal boundary conditions of gases contacting with a cylinder head were determined by comparing them with the results of a routine test. A fluid-structure interaction model between the cooling water and cylinder head passages was established in which boundary conditions of cooling water were obtained by computational fluid dynamics analysis. Simultaneously, considering the pressure mechanical load in the cylinder, temperature and the stress distribution of the cylinder head were analysed by the model with a thermo-mechanical coupling load. The model was validated using the temperature hardness plug method. Four parameters of intake valve opening, exhaust valve opening, fuel supply beginning, and compression ratio were selected as influencing factors, and the thermo-mechanical coupling load of the cylinder head was optimised by the Taguchi and analysis of variance method subsequently. The study indicates that the error of the calculation model for the cylinder head’s thermal-mechanical coupling load is within ±1.5%, and the proportion of the thermal stress in the cylinder head thermal-mechanical coupling stress is above 90%. The fuel supply beginning has the greatest influence on the thermal load of the cylinder head. Based on the optimisation methods within the required power range, the maximum temperature and maximum thermo-structural coupling stress of the cylinder head are decreased by about 10.05 K and 7.13 MPa in the nose bridge area, respectively.

The evolution of founder identity as an authenticity work process

Research has shown founders' identities have a significant impact on their ventures. Yet, the process through which founder identity evolves and takes shape remains relatively unexplained. This paper explores the evolution of founder identity through a qualitative study of first-time sustainable entrepreneurs, and their stakeholders, over a three years period. Our analysis revealed the importance of personal identity, the aspect of the self that defines a person as a unique individual based largely on values and beliefs. We found that first-time founders sought to align their personal identity with their evolving founder identity over time. Based on these findings we theorize a process model of founder authenticity work, defined as the activities founders engage in to feel and seem authentic while engaged in entrepreneurial action. This study thus details the significance of personal identity as a guidepost for founder identity evolution, complementing extant founder identity studies focused on role and social identities. In addition, our analysis enriches the current conceptualization of authenticity in entrepreneurship research by linking it to validation of personal identity and highlighting its negotiated nature in the evolution of authentic founder identities.

МЕТОД ПРОЕКТИРОВАНИЯ ЭЛЕКТРОГИДРАВЛИЧЕСКИХ ПРЕОБРАЗОВАТЕЛЕЙ АВИАЦИОННЫХ ДВИГАТЕЛЕЙ

The main trends in the use of aircraft engines actuators, that convert electrical commands into mechanical and hydraulic, are presented. Examples of the use of modern engine control systems are described, in which hydraulic cylinders are used to move the actuators. The hydraulic commands for moving hydraulic cylinders are formed by electro-hydraulic converters. A significant increase in the modern engines mechanization complexity required an increase in the reliability of electro-hydraulic converters and the level of static and dynamic characteristics. The necessity of introducing a new generation of electro-hydraulic converters into the control systems of domestic aircraft engines is discussed. The analysis of the list and method of determining indicators using which it is advisable to control the balanced conformity of the design to the technical requirements at the design stage is carried out. A model-oriented approach to the design of electro-hydraulic converters is described. The structure of a universal model of the working process of an electro-hydraulic converter is proposed. A feature of the model is the predominant use of the geometric parameters of the elements and properties of materials as initial data. The main constituent elements of the working process model are the models: an electromechanical converter with an elastic part, a preliminary stage, orifices, volumes of compressible fluid and attached masses. The main parameters of the actuator, external parameters (defined in the technical requirements for the whole product) and internal parameters (characteristics of the hotel units) of electro-hydraulic converters are highlighted. The analysis of the dependence of external and internal parameters and the parameters of the actuator. The design method of electro-hydraulic converters is given. A key feature of the method is the use of a workflow model at almost all stages of design. To form a balanced combination of parameters of the electro-hydraulic converter in the structure of the method, it is proposed to use the objective function, which includes the internal parameters of the electro-hydraulic converter.

A Zero-Dimensional Mixing Controlled Combustion Model for Real Time Performance Simulation of Marine Two-Stroke Diesel Engines

The paper presents a performance prediction model of marine low-speed two-stroke diesel engines based on an advanced MCC (mixture controlled combustion) model coupled with a fuel injection model. Considering the time of real calculation, the so-called “concentrated exhausting gas” scavenging model and the working process model are used in the present work, and improved by introducing the ratio of pure combustion product over the total gas mass in the cylinder as an expression of the working medium components. The reaction rate model in the zero-dimensional MCC model is improved by introducing the fraction of combustion product in the fuel spray, and the relationship between the combustion model and scavenging quality is established. Meanwhile, the combustion model was simplified in the diffusion combustion phases and integrated with the fuel injection model in order to respond to the change of injection profile and injection timing. A large-scale low-speed marine diesel engine was used for a simulation. The results of the whole model are consistent with experimental data and the speed of calculation is fast enough for real time simulation of low speed and medium speed diesel engines. The prediction model can be used in the design and calibration of the electronic control system and performance optimization of the marine two-stroke diesel engine.

Математическая модель процесса работы конусного раскатчика

Тиллоев Кудратулло Зувайдуллоевич, аспирант кафедры «Колёсные и гусеничные машины», Южно-Уральский государственный университет, г. Челябинск, kudratullo.tilloev@bk.ru. K.Z. Tilloev, kudratullo.tilloev@bk.ru South Ural State University, Chelyabinsk, Russian Federation

Model of Processes of the Al25/30 Marine Engine and its Verification

Abstract The work presents a model of the marine diesel engine working process. The research object was the AL25/30 engine. The model consists of partial models of the combustion process in the engine cylinders, the heat exchange process, flows through air and exhaust channels, heat exchange in the intercooler and friction in mechanical components of the engine. The model includes a description of the processes taking place in the turbocharger also. The input data to the model and the verification data were the results of direct measurements on the research facility. The verification showed errors in the calculation of air and exhaust gas parameters not exceeding 11%. The paper also presents an analysis of the results of fast-changing parameters, including combustion pressure in engine cylinders and pressures in individual gas channels. The designed model allows the analysis of the research facility operation and enables its further development towards the assessment of toxic compounds emission to the atmosphere.

Analysis on the heat-recuperable hybrid cycle for micro swing engine with a non-isometric multi-chamber structure

With low efficiency and insufficient power, the conventional micro swing engine has not been available for portable power source. Therefore a novel hybrid thermodynamic cycle with heat recuperation ability, which is suitable for the micro swing engine, is proposed to overcome the above defects, whose thermodynamic characteristics are investigated in details, indicating a great improvement for the engine performance. Firstly, the micro swing engine is modified to be a three-arm engine with a non-isometric multi-chamber structure. Driven by the hybrid cycle, the engine body and a specially designed spiral recuperator work together successfully in theory. Thus, the entire efficiency is increased by heat recovery from hot exhaust and restriction of structural heat leakage. In consideration of flow leakage effect, simulation models of the steady working process of the engine in hybrid cycle are established. Numerical results reveal that, thermal performance of the hybrid cycle has an obvious advantage over the single thermal cycle. Moreover, the hybrid cycle is composed of two single four-stroke cycles and two two-stroke cycles. The two adjacent cylinders, between whom the flow leakage happens, are with different cycles, and hence distinct thermal performances. Finally, with the application of this heat recovery process, the efficiency of the four-stroke cylinders is improved relatively by 45.31% and the total engine efficiency is increased by 14.09%. Effectiveness and practicability of the hybrid cycle with heat recuperation are demonstrated theoretically, which is of great significance for the progress in micro heat engine field.

Fast and slow thinking: Electrophysiological evidence for early conflict sensitivity

Popular dual process models have characterized reasoning as an interplay between fast, intuitive (System 1) and slow, deliberate (System 2) processes, but the precise nature of the interaction between the two systems is much debated. Here we relied on the temporal resolution of electroencephalogram (EEG) recordings to decide between different models. We adopted base-rate problems in which an intuitively cued stereotypical response was either congruent or incongruent with the correct response that was cued by the base-rates. Results showed that solving problems in which the base-rates and stereotypical description cued conflicting responses resulted in an increased centro-parietal N2 and frontal P3. This early conflict sensitivity suggests that the critical base-rates can be processed fast without slow and deliberate System 2 reflection. Findings validate prior EEG work and support recent hybrid dual process models in which the fast System 1 is processing both heuristic belief-based responses (e.g., stereotypes) and elementary logico-mathematical principles (e.g., base-rates).

Análise bibliográfica das iniciativas de prevenção da lesão por pressão em adultos internados em Unidade de Terapia Intensiva

Este estudo possui como objetivo realizar uma análise das iniciativas de prevenção das lesões por pressão em adultos internados em Unidades de Terapia Intensiva, as quais foram publicadas em literatura científica da área de Enfermagem. Trata-se de uma revisão bibliográfica integrativa, a partir de coleta de dados de 12 artigos em bases virtuais nacionais e internacionais dos últimos 10 anos. Dentre as iniciativas de prevenção da lesão por pressão evidenciou-se que a maior parte encontra-se na área de segurança do paciente, principalmente com a aplicação das escalas de Braden, Glasgow e o protocolo internacional relativo a meta 6 da Segurança do Paciente, orientado pela Organização Mundial de Saúde. Identificou-se um número ainda reduzido de estudos que demonstrem outras iniciativas de prevenção deste tipo de lesão, além da aplicação de escalas e protocolos de classificação e prevenção do referido evento adverso. Em artigos mais recentes, a partir de 2013, se encontram descritas ações educativas e de modelagem de processo de trabalho, que levam a adoção de uma cultura de segurança do paciente e estabeleçam um indicador de qualidade ao serviço de saúde como também do grau de cuidado da equipe de enfermagem.

Female Faculty's Involvement in Work Processes in Saudi Arabia

The purpose of this study was to examine the role of gender as a potential determinant of involvement in higher education institutions in Saudi Arabia. This study focuses on four specific categories of involvement: power, rewards, information, and knowledge. It utilized Edward Lawler's model of high involvement work processes to measure the involvement among female faculty in the University of Dammam, Saudi Arabia. Edward Lawler's model is one of the first and widely cited models on employee involvement. This study further investigates the relation between the faculty's demographic variables (academic rank, college cluster, years of experience, and nationality) and their involvement. A survey research design was utilized to better address the purpose of this study. The sample consisted of 135 female faculty members. The findings show a moderate level of involvement among the respondents. Of the individual practices of involvement, power was the most wide-spread practice, with a mean rating of 3.72 and a standard deviation of .786, based on the five-point scale. Regarding the demographic variables, only college cluster was found to be significantly related to females' involvement. The implications of this study could be used to further support involvement policies and practices among female faculty members in Saudi Arabia.

High-Altitude Matching Characteristic of Regulated Two-Stage Turbocharger With Diesel Engine

To improve engine power at high altitude, the regulated two-stage turbocharger (RTST) which was applied to different altitudes was developed by the authors. The working process model of heavy-duty common-rail diesel engine matched with RTST was built to study the regulating characteristic of variable geometry turbocharger (VGT) vane and both turbine bypass valves and also matching performance of RTST with engine at different altitudes. The control scheme of RTST at different altitudes and engine operating conditions was first put forward, and the optimal opening maps of VGT vane and both turbine bypass valves at different altitudes and engine operating conditions were obtained. The results show that the optimal openings of VGT vane and both turbine bypass valves decrease with increase of altitude, and the optimal opening range of VGT vane becomes narrower with increase of altitude. The operating points of both high-pressure (HP) and low-pressure (LP) compressors locate at high-efficiency region of each compressor map, respectively, and compressor efficiency exceeds 70% at altitude of 5500 m. The total boost pressure ratio increases with altitude and reaches the maximum value of 5.1 at altitude of 5500 m. Compared with single-stage turbocharged engine, the rated power, maximum torque, and torques at lower engine speed at altitude of 5500 m increase by 48.2%, 51%, and 65–121% separately, and the minimum fuel consumption decreases by 12.6%.

Building information modeling (BIM) collaboration from the structural engineering perspective

Collaboration is essential for protecting investments and increasing the competitiveness of the construction industry. This study presents the possibility of information interoperability from the structural engineering perspective and aims to maximize the building information model (BIM) collaboration to improve both the work efficiency and quality of structures. In particular, this study analyzes and reviews the possibility of information interoperability in BIM between the structure, construction, architecture, and work-process models by considering the structural engineering perspective in the collaboration. To achieve information interoperability, Open BIM is used as the principal method, and an application-programming interface (API) is used as a secondary method. The level of development (LOD) information interoperability is limited to LOD 300. The analyses and reviews discuss the possibility of practical applications of information interoperability between models in BIM from the structural engineering perspective. Furthermore, an increase in the work efficiency and structural quality is pursued through the BIM collaboration.

The concept of creating universal systems for the environmental certification of transport diesels based on mini- and microtunnels

Purpose. Creation of a scientific and practical basis for the development on the basis of mini and micro tunnels of universal low-cost systems for the environmental certification of transport diesel engines in terms of the mass emission of particulate matter with exhaust gases. Methods. Analysis and synthesis of information when studying the systems of ecological certification of diesel engines, physical and mathematical modeling, experimental research of working processes, technical characteristics and efficiency indicators of tunnels. Results. The technical characteristics of mini and micro-tunnels as control systems for mass emissions of diesel particulate matter are considered. The concept of the creation of universal mini- and microtunnels is proposed based on the principles of increasing their compactness, dynamism, management efficiency and accuracy. Conclusions. The results of theoretical and experimental researches and developments on increasing the universality of mini- and microtunnels are presented: mathematical models of work processes, resulting errors and performance indicators of tunnel; new isokinetic and compensation methods for controlling exhaust gas samples; prototypes of a minitunnule with an isokinetic sampler MT-1, microtunnels MKT-1 and MKT-2; test benches for studies of thermal processes in tunnels, isokinetic and compensation sampling regimes; results experimental development of certification procedures for measuring emissions of particulate matter from automotive, tractor and diesel locomotives.

Dynamic model of the inertial hydrodifferential transformer working process of the rotating moment in various automatic machine drives

Dynamic model of the inertial hydrodifferential transformer working process of the rotating moment in various automatic machine drives

Generating Novelty Through Interdependent Routines: A Process Model of Routine Work

We investigate how multiple actors accomplish interdependent routine performances directed at novel intended outcomes and how this affects routine dynamics over time. We report findings from a longitudinal ethnographic study in an automotive company where actors developed a new business model around information-based services. By analyzing episodes involving interdependent routines, we develop a process model of routine work and dynamics across routines. We identify three types of routine work (flexing, stretching, and inventing) that generate increasingly novel actions and outcomes. Flexed, stretched, and invented performances create emerging consequences for further actions across routines and surface differences between actors that could lead to breakdowns of routine work. Actors respond to such consequences through iterative and cascading episodes of routine work. We discuss how our findings provide new insights in efforts to create variable routine performances and the consequences of interdependence for routine dynamics.

Articulation of work process models for organizational alignment and informed information system design

Articulating and representing procedural aspects of work in conceptual models is a prerequisite for informed information system (IS) design. Instruments supporting articulation need to establish common ground about the interaction of the collaborating actors. This article proposes a methodology for the articulation of work processes by inexperienced modelers. It consists of phases of articulation and consolidation of case-based models and interactive elaboration toward comprehensive representation of the process via virtual enactment. The resulting models can be directly interpreted by IS. A case study confirms that the methodology meets the identified requirements and identifies areas of improvement.

Determination of transfer functions of the automatic electrohydraulic drive for special process equipment

This article discusses the improvement of special technological equipment due to the development of mathematical models of work processes that occur in the equipment and take into account the particular purpose of the process equipment. The main objective is to construct a mathematical model and obtaining the transfer functions of the electro-hydraulic drive equipment with passport data of standard devices and drive devices. The linearization of the mathematical model is made on the basis of the analysis of dynamic and statistical characteristics of work processes in equipment subject to a number of assumptions. The developed mathematical model and transfer function of the system allows you to perform a stability analysis, assessment of the quality of regulation and correction of dynamic characteristics based on passport data elements of the drive. The research results can be used by engineers involved in the development of automatic control systems of special technological equipment. A mathematical model is proposed in the work enables the development of automatic control system, which will expand the functionality and efficiency of special technological equipment.

A THEORETICAL MODEL OF SOCIO-PSYCHOLOGICAL SUPPORT WORK PROCESSES FOR MANAGEMENT OF PRODUCTION TEAM

В данной статье рассматривается вопрос управления производственным коллективом, в частности разработана теоретическая модель социально-психологической работы по сопровождению процессов управления производственным коллективом. Автором исследования сформулированы цель и задачи социально-психологической работы по управлению производственным коллективом. Разработанная в исследовании теоретическая модель нацелена на определение условий и выявление особенностей эффективного управления предприятием с учетом социально-психологических характеристик его коллектива. Задачами являются: определение основных характеристик производственного коллектива и степени их выраженности, анализ этих характеристик и определение возможностей их трансформации, разработка рекомендаций по ведению социально-психологической работы по воздействию на характеристики коллектива предприятия. Практическое изучение деятельности ряда предприятий показало необходимость совершенствования социально-психологического сопровождения процессов управления производственным коллективом: ввести социальное и психологическое планирование коллектива и развивать практику социологических исследований состояния коллектива, обеспечить сглаживание отношений между работниками и руководством посредством проведения периодических совещаний, созданий условия для обратной связи, поддержания здоровой конкуренции между членами коллектива.