Model Of Working Process Research Articles

THE AIRCRAFT ENGINE PROPELLER MAIN CHARACTERISTICS DETERMINATION IMPROVED METHOD

An improved method of the fixed and variable pitch propeller aerodynamic characteristics determining that based on the vortex theory is presented. It is shown that the design of propellers has it`s peculiarities, it does not take into account a number of factors that affect the propeller operation to one or another degree. This actualized the special purpose unmanned aerial vehicles engines propellers aerodynamic characteristics calculating methodology improvement. Since the use of the propeller profiles performances in the design requires the air compressibility correction introduction already after the selection of the propeller, that complicates the design, therefore the mathematical model of the variable-pitch propeller working process has been improved based on the profile model with the correct consideration of the Mach and Reynolds numbers influence on the aerodynamic characteristics of the air screw. This advantage of the developed airfoil model allows the design and verification of a subsonic propeller for ground and flight operations. Methods of design and verification calculations of propeller blades are presented. Verification of the improved methodology was carried out by comparing calculated data with known experimental data. The reliability of the improved aircraft engine propeller main performances determination methodology is substantiated by the correct application of the numerical and experimental methods of aerodynamics, the consistency of theoretical provisions with experimental data. The satisfactory coincidence of the calculated data obtained by the improved method of the engine propeller main performances determination allowed us to draw a conclusion concerning its efficiency. The improved technique for the main performances of an aircraft engine propeller determination does not require knowledge on the propeller profiles aerodynamic characteristics from which the blade is drawn, since these characteristics are calculated based on known geometric data, taking into account the Mach and Reynolds numbers. This allows you to design and build a subsonic propeller of both fixed pitch and variable pitch.

Working process model development of the gas turbine engine combustor fueling on methanol

The use of methanol as a fuel for aircraft and stationary gas turbine engines (GTE) is a priority direction in engine building. It is well known that when modeling the GTE performances using first-level mathematical models, there is an error in calculating specific fuel consumption, which is caused by the simplified description of the GTE combustor working process. The object of the study is the working process in the GTE combustor fueling on methanol. The peculiarity of the developed mathematical model of the working process of the GTE combustor is the use of enthalpy dependencies on temperature, pressure, and mixture composition. Enthalpy dependencies in this form implicitly account for the effect of thermal dissociation and allow for the correct formulation of the equivalent combustion reaction path. For two components (H2O and CO2), accounting for pressure leads to the fact that at standard temperature and partial pressures exceeding the saturation pressure, these components exist in a liquid state. This situation, with a constant enthalpy increment in the equivalent process of heating the combustion products from the standard temperature to the temperature at the end of adiabatic heat supply, decreases this temperature. Clarification of the temperature at the combustor outlet leads to changes in all calculated combustor performances, including the combustor fuel air ratio. The calculation results of the fuel air ratio are compared with known experimental data of the General Electric CF6-80A engine combustor (USA). The average calculation error of the fuel air ratio does not exceed 4 %. The developed model can be implemented in existing and developing mathematical models of gas turbine engines for temperatures at the end of the combustion process below 2,600 K

Determination of optimal technological parameters of a horizontal mixer of loose compound feeds

The quality of the compound feeds for animals and poultry directly depends not only on the components included in it but also on the type of mixer used. Horizontal mixers as compared to the vertical ones allow for a shorter period of time to obtain high-quality mixtures due to the intensification of the process of material movement by belt working bodies. The aim of the research is to determine optimal technological parameters of a horizontal mixer with a 0.3 m3 mixing chamber with a belt working body. The mixer is designed to produce mixed compound feeds of high uniformity in production lines, workshops or can be used as an independent machine for mixing loose components. The research was carried through multifactorial experiment. As the result, mathematical models of the mixer working process were obtained, two-dimensional cross sections of the response surfaces were built. The obtained mathematical models make it possible at the design stage to identify the dependence of qualitative and energy indicators on factors at the considered levels of variation. According to the results of the multifactorial experiment, it has been established that the best mixing quality of 94.8 % is achieved when the mixing chamber is loaded by 58 % at a speed of rotation of the mixer shaft of 30 min-1, mixing time of 6 minutes with simultaneous supply of the control and the main components. At the same time, the throughput is 0.78 t/h, and the specific energy consumption is 2.04 kWh/t.

A Process Model of Formative Work to Strengthen a Prison Health Surveillance System.

Worldwide, there is a lack of systematically collected health data on people who are incarcerated. Our objective in this paper was to describe a process model of formative work for a project to strengthen health surveillance for people incarcerated under a Canadian prison authority. We have developed project structures and processes, and we are evaluating project partnerships. To inform prison health surveillance foci, we are conducting a review of literature on best practices, a qualitative study to understand stakeholders' needs and priorities, and mapping work to understand available prison health-related data. Developing and implementing prison health surveillance is gradual and developmental, necessitating time to build relationships and obtain approvals. The needs and interests of knowledge users should be prioritized, but there may be challenges to achieving a coherent vision due to feasibility and differing needs and objectives of various stakeholders. Developing collaborative relationships could help bridge this gap.

Fatigue life analysis model of crankshaft under uncertain working conditions based on physical-data collaboration

The uncertainty of working conditions often affects the fatigue life of the crankshaft. In order to study the impact of uncertain working conditions on the fatigue life of the crankshaft, the fatigue life analysis model of crankshaft under uncertain working conditions was established based on the engine working process model, equivalent stress calculation model, fatigue life calculation model and surrogate model. The engine working process model was established based on the filling and empty method to simulate engine performance under different working conditions, and the accuracy of the model is verified by experimental data. The equivalent stress calculation model under uncertain working conditions was established by combining the performance data with the equivalent stress calculation model. Based on the fatigue life curve, the transformation from equivalent stress to fatigue life can be realized, and the fatigue life of crankshaft under uncertain working conditions can be obtained. Finally, the relationship model between working condition and fatigue life was established based on the Kriging surrogate model. Through comparative analysis, the calculation errors of the established equivalent stress calculation model and fatigue life calculation model are 2.6% and 1.9% respectively. This study not only establishes the relationship between fatigue life and working conditions of crankshaft based on physical-data collaboration, but also provides an effective model basis for follow-up crankshaft reliability analysis.

ENHANCED DIAGNOSTIC TECHNIQUES FOR MARINE DIESEL ENGINES: ACHIEVING IMO DECARBONIZATION COMPLIANCE

This paper discusses hardware-based methods for monitoring the operational parameters of marine diesel engines and online mathematical modeling techniques (digital twins) for calculating the emissions of CO2, NOx, soot, and other harmful pollutants. It is demonstrated that measuring and analyzing the engine's vibrational diagrams in parallel with gas pressure diagrams in the cylinders allows the evaluation of the actual fuel injection and gas distribution timings. The obtained data is used to refine the mathematical model of the engine's working process, which determines the engine's indicator parameters and power, as well as the emission of harmful substances that need to be monitored in compliance with current IMO requirements. The authors have accumulated experience in using the discussed hardware-based methods for diagnosing marine engines during operation. The hardware and software methods discussed have been implemented into a real-time system for in-service diagnostics of marine engines. The system is designed based on a modern dual-core controller with high performance and low power consumption, incorporating a high-speed ADC with sufficient capability to monitor the working process with a 0.1-degree crankshaft rotation resolution for all types of marine main and auxiliary engines. The system also utilizes wireless data transmission technology. A contemporary Android/iOS smartphone or tablet serves as the computational and graphical component of the system. This real-time system enables the utilization of all the advantages of parallel pressure and vibroacoustic analysis, including real-time determination of key operating parameters, identification of top dead center position, and evaluation of fuel delivery and gas distribution phases. Additionally, it harnesses the benefits of employing a digital twin—an online mathematical model of the engine cylinder's working process. These solutions will enhance diagnostic quality and, ultimately, improve the operational efficiency of marine engines by reducing operational costs and extending the period of reliable, trouble-free operation.

To regulate or not to regulate: unravelling institutional tussles around the regulation of algorithmic control of digital platforms

Regulating how digital platforms use algorithms to determine and control content displayed to their users is both a controversial topic and an important societal challenge. Existing research acknowledges institutional tussles around regulating how digital platforms use algorithms to determine and control content. However, we lack research showing how the development of regulation unfolds. We build on data from a longitudinal discourse analysis of 410 media articles and 483 policy and industry documents to study two cases of algorithmic control regulation in Australia. The first involves algorithmic control for content display, the second for content moderation. We develop a process model of institutional work towards regulation of algorithmic control. It captures the institutional tussles between governments, digital platforms and third parties as each expresses their perspective on legitimate forms of algorithmic control and shapes the process and outcome of regulation. Building on our model, we discuss the dynamics of regulation development in light of the constellation of actors and their power position in the process. We further consider the regulatory outcome and highlight future research questions that build on our findings.

Development and Research of a Promising Pumpless Liquid Cooling System for Reciprocating Compressors

A new pumpless liquid cooling system for a single-stage two-cylinder reciprocating compressor has been developed from the analysis of work processes and cooling systems of reciprocating compressors, where one piston compresses and moves gas and coolant in the cooling system. The intensification of the coolant movement increases in the machine, which can reduce the temperature of the cylinder–piston group and increase the indicator efficiency and the compressor feed rate. A mathematical model of working processes in a reciprocating compressor and its cooling system has been developed on the basic fundamental laws of conservation of energy, mass and motion. A prototype was developed and tested to obtain new knowledge about the processes in the machine and confirm the assumptions made while developing the mathematical model. After a series of experiments, the influence of cooling on the working processes in a reciprocating compressor, the technical work carried out in each working process, the energy and consumption characteristics of a reciprocating compressor with a developed cooling system were established. There was a validation performed of the developed mathematical model of work processes in the machine and the assumptions made. According to the developed mathematical model of work processes, a numerical experiment was carried out, which established: the coolant flow rate decreases with an increase in discharge pressure and increases with an increase in the crankshaft speed when the discharge pressure changes from 0.4 MPa to 0.8 MPa, a decrease in the indicator isothermal efficiency due to the leakage and non-isothermal nature of the compression process, as well as a decrease in the return work in the process of reverse expansion, leading to a decrease in the indicator isothermal efficiency of more than 15%; due to the equalization of pressures in the gas cavities with an increase in discharge pressure, the coolant consumption is reduced by (15 ± 17)%; with an increase in the angular speed of the crankshaft from 800 rpm to 1500 rpm, the coolant flow rate increases by more than 2.5 times, this increase in coolant flow rate is due to an increase in hydraulic resistance due to an increase in gas velocity; in the range from 1000 to 1200 rpm, a maximum of the indicator isothermal efficiency and compressor feed rate is observed; maximum indicator isothermal efficiency and the supply ratio is observed at a coolant flow rate in the range from 800 mL/min to 900 mL/min.

Proposing a Quality Inspection Process Model Using Advanced Technologies for the Transition to Smart Building Construction

With advancements in new technologies in the industry, efforts have been made to adopt various smart devices during the life cycle of building construction. However, little attention has been paid to developing a work process model to maximize the benefits of smart technologies. While identifying the shortcomings of conventional quality inspection, this study configures a new quality inspection process model in collaboration with smart devices. Based on the proposal, the study developed a new tool that effectively improves the current quality inspection practice. The final goal of this research is to propose a novel inspection process model by developing an Application Programming Interface (API) system using Building Information Model (BIM) software. Additionally, to verify the applicability of the system, this study includes a case study on tile work and confirms the effects of a prototype of the proposed system through an expert survey. The survey results reveal that the proposed system is effective and practical. This research contributes to maximizing the effectiveness of using smart devices and supporting effective application in smart construction.

K-평균 알고리즘을 이용한 스마트팜 농작업별 소요시간에 따른 군집분석

This study attempts to establish a standardized model of smartfarm working process for paprika. First, we classify main works by each production stage and then we evaluate difficulties and lengths of major works by cross-check. Finally we investigate real working hours of each main work in twenty paprika smartfarms. Based on the real data of working hours, we utilize a cluster analysis using the K-means algorithm and Silhouette method in order to categorize paprika smartfarms. The results from the K-means cluster analysis show that sixteen farms were clustered into ten groups. We conclude that each farm was not clearly categorized.

Способ выравнивания мощностей цилиндров многоцилиндрового тепловозного дизеля

Purpose: Labor intensity reduction and equalization accuracy improvement of cylinder powers of a multi-cylinder diesel locomotive on account of application as a diagnostic parameter, characterizing cylinder power unevenness, — the energy of low-frequency band of spectrum for crankshaft instantaneous angular velocity (CIAV) signal. Methods: Methods of mathematical modeling of diesel crankshaft instantaneous angular velocity, mathematical modeling of diesel engine working process, digital signal processing, spectral analysis, differential calculus and multidimensional non-differentiable function optimization are used in the work. Results: Method for equalization of cylinder powers of a multi-cylinder diesel locomotive that’s based on a continuous monitoring of the spectrum of crankshaft instantaneous angular velocity signal is proposed and justified. Energy of low-frequency band of the signal spectrum of CIAV can be used as a diagnostic parameter, characterizing cylinder load unevenness. The parameter value minimization by means of sequential correction of cyclic fuel supply and fuel advance angle ensures the decrease in the pointed unevenness. Practical importance: The proposed method can be used when adjusting fuel equipment after the repair of a diesel engine as with electronic fuel supply control systems as well as with hydromechanical fuel equipment. The use of the given method excludes the necessity of temperature measurement for exhaust gases and flash pressure measurement in cylinders for fuel equipment adjustment that’s especially important for high-speed diesel engines which cylinder heads’ construction doesn’t provide for indicator cocks. In the engines equipped with electronic fuel control systems, the use of IAV signal spectrum low-frequency band energy as a diagnostic parameter makes it possible to automate fully the equalization process for cylinder load. The result of the proposed method application will be the reduction in the duration and labor intensity of diesel locomotives rheostat tests as well as the rise in diesel locomotives reliability and efficiency at the expense of uniform loading of diesel cylinders.

Learning to Listen

Learning to Listen

“Do I Have the Right?” The Process Model of Identity Work in a Leadership Development Program

Through a qualitative study of thirty Russian managers and entrepreneurs who graduated from an eighteen-month Master of Business Administration Program (MBA) in Moscow, Russia, the research proposes a process model of leadership identity work and leader efficacy development within a management education program. Key research findings reveal that the leadership identity work in a leadership development program is fuelled by people's efforts to promote their leader efficacy, and the institution helps them in this process as a holding environment. The study proposes that the identity work in a leadership development program unfolds in four phases: preparation, orientation, experimentation and confirmation. In this process, an institution serves as a supporting community, training camp, exploratory journey and a confirmation agent.

Efficiency improvement of Roots vacuum pump working process

SummaryIn this paper influence of rotor profile type of Roots vacuum pumps on backward leakage through channels of rotor mechanism and pumping speed is considered.Elliptical, involute, and circular profiles are widely used. Backward leakage through channels of rotor mechanism with different rotor profiles is determined from conductance which was calculated by angular coefficients method for free molecular flow regime at different rotors rotating angles. It is shown that backward leakage is maximal at rotors rotating angles 25–45° due to maximal inter‐rotor channel opening for gas flow and is minimal at 0°. Elliptical rotor profile provides minimal backward leakage over one revolution.Numerical modeling of Roots pump working process was carried out on the basis of CFD ANSYS‐CFX complex by dynamic meshing method. SST turbulence model was used for calculations. It is confirmed that maximal pumping speed is provided by Roots pump with elliptical rotor profile.

Lean Office: The Lean methodology applied to the improvement of administrative processes in a Higher Education Institution

With the advent of globalization, provided in part by the advancement of information and communication technologies (ICT), has allowed companies in different segments and on different continents to have a significant increase in their visibility on the world market, thus requiring them to be more competitive with other companies. The specific objectives are the following phases: to carry out a survey of the current conditions of the administrative procedures related to the sector of the Directorate of Administrative Services, as well as their demands and results; to verify at which stages of the processes there is a waste of time in the execution of these administrative procedures, that is, to identify opportunities in the procedures practiced by the IES; to propose improvements based on LO thinking for each of the opportunities found; and finally to identify to what extent the results, or the deliveries made, have had a significant improvement from the proposition of applying LO concepts. As a research method, it will use the following tools: bibliographic research, documentary research, statistical treatments, Quality Management, Value Flow Map, using the 5S tools, Standardized Work, SIPOC, Visual Management and Business Process Model and Notation (BPMN). To this end, LO concepts will be used for the organization, the survey, analysis and proposals for improvements in the identified processes. As a result, there is an alignment among its employees and compliance with all mapped activities, without rework and with significant results.

Развитие средств термодинамического расчета характеристик ракетного двигателя с использованием языка программирования Julia

The experience in developing an algorithm and a program for the thermal-chemical calculation of the characteristics of a rocket engine is presented. The program is written in Julia. To calculate the equilibrium composition of combustion products the freely distributed library Ipopt is used. The program is interfaced to the database on thermodynamic properties of individual substances IVTANTERMO. For the convenience of processing, the information on thermodynamic properties is stored in two text files of a special form. The program has been developed using the simplest working process model according to which the flow is one-dimensional, the product flow is adiabatic, there are no friction losses, the product flow is equilibrium, and the speed of condensed particles is equal to the gas flow speed. Ratios for calculating the derivatives of composition, as well as equilibrium values of heat capacity and sound velocity are given. The text of the program can be used in the study process and can easily be adapted to more complex models of the rocket engine workflow. The calculation results obtained using the developed program are in good agreement with the results of TERRA calculations. The execution time of one calculation for a four-element fuel, which includes the determination of the combustion products characteristics in the chamber, the critical cross section and at the nozzle cross section, varies in the range of 3--5 s

ТЕОРЕТИЧЕСКОЕ ИССЛЕДОВАНИЕ КИНЕМАТИЧЕСКИХ И ДИНАМИЧЕСКИХ ХАРАКТЕРИСТИК ШНЕКОВОГО РАБОЧЕГО ОРГАНА ЛЕСОПОЖАРНОЙ ГРУНТОМЕТАТЕЛЬНОЙ МАШИНЫ

The paper presents the results of studies of the working processes of screw working bodies in various industries. Studies of the technological parameters of screw working bodies during the removal of the ground cover with combustible plant residues have been insufficiently carried out. A new design of a forest fire machine is proposed, including screw working bodies for removing the ground cover with combustible plant residues, cut-out discs, for the formation of a soil shaft in front of the rotor-thrower, with an adjustable guide casing with the ability to change the directional flow of soil. Working bodies of the forest fire soil-throwing machine are described by a system of differential equations of the translational, rotational movements of the auger working body and the equation of the flow rates of the working fluid. The Cauchy problem is considered on the interval t∈ (t_0; t_end). Original system is reduced to a system of recurrence relations due to its nonlinearity, replacing the derivatives of the desired functions with their finite analogs. This system is unresolved with respect to the senior member. One can apply the method of splitting the system into systems in subspaces of decreasing dimensions and solve the system in these subspaces due to the Fredholm property of the operator coefficient in front of the leading term. The analytical solution of the mathematical model for removing the ground cover by auger working bodies of a forest fire soil-throwing machine when laying fire strips and extinguishing grassland forest fires makes it possible to determine the kinematic and dynamic parameters of the auger working bodies using the final formulas. Simulation modeling of the screw working process was carried out on a virtual laboratory bench. The dependences of the dynamic characteristics of the auger working bodies when overcoming obstacles have been obtained. It was found that the maximum average value of the torque is observed when overcoming an obstacle with a height of 100 mm and the rotation speed of the working body of 400 rpm is 1468.49 N ∙ m, at which its performance is not impaired.

Analysis of the influence of geometric parameters on working processes in a two!stage hybrid power machine of positive displacement without a gas cap with a profiled working chamber of the second stage

A principal scheme is considered and a mathematical model of work processes is developed in a two-stage hybrid power machine of positive displacement without a gas cap with a profiled working chamber of the second stage. The mathematical model is based on the basic laws of conservation of energy, volume and mass for a dropping liquid and a compressible gas in the second stage. The diameter of the supply pipeline and the initial radius of the profiled working chamber in the second stage are selected as the main geometric parameters that have the greatest influence on the work processes. The response functions are found that determine the dynamics of the fluid flow in the machine under study and its main integral characteristics. Keywords: work process, cooling, reciprocating compressor, hybrid power machine of positive displacement, profiled working chamber Scherba_V_E@list.ru

Использование бутанола в дизелях в качестве моторного топлива

The article presents the results of computer modeling and experimental research of the effect of butanol content in the fuel on the specific power, fuel-economic and environmental performance of 4ЧН 11/12.5 (4ChN 11/12.5) diesel engine at various cycle fuel supplies and exhaust gas recirculation rates. The research has been carried out at crankshaft speeds of 1,000, 1,200, 1,400, 1,600, 1,800, 2,000 and 2,200 rpm with 25, 50, 75 and 100 % load. Fuels with butanol content of 5, 10, 15, 20, 25, and 30 % by volume have been investigated. The computer model of the diesel working process has been developed that takes into account the physical and chemical properties of the fuel, the characteristics of the fuel flow in the nozzle tip and the development of fuel sprays in the combustion chamber. Based on the results of computer modeling, dependencies have been determined that make it possible to assess the effect of the percentage of butanol in mixed fuel on the mean indicator pressure, specific fuel consumption, indicator efficiency, emissions of nitrogen oxides and dynamic indicators of the combustion process when choosing the composition of mixed butanol-containing fuel. Based on the conducted research, the following composition of mixed fuel has been selected: 85 % diesel fuel and 15 % butanol. Comparative tests of the diesel engine have been carried out when working on the external speed characteristic on diesel fuel and its mixture with 15 % butanol. It is obtained that when using mixed fuel, the character of the power change remains unchanged, the exhaust smoke decreases, nitrogen oxides emissions decrease at crankshaft speeds of 1,400, 1,600, 1,800, and 2,200 rpm, and the effective engine efficiency remains practically unchanged.

Физико-математическая модель рабочего процесса струйного эжектора

A refined physical model of the jet ejector working process has been compiled. On the basis of the refined physical model, a mathematical model has been developed that takes into account the exchange of work and heat between the ejected and ejected gases. Based on the solution of this mathematical model, it is possible to formulate a method for calculating the optimal geometric dimensions of the jet ejector to obtain the specified thermodynamic parameters and a method for calculating the characteristics of the jet ejector with known geometric dimensions. The effect of viscosity on energy exchange is shown. The agreement between the calculated and experimental data is satisfactory.