Complex Mathematical Models Research Articles

Optimization of the operating mode of a squirrel-cage induction motor

THE PURPOSE. The presented work aims to optimize the operating mode of an asynchronous motor (AM) with a short-circuited rotor. To implement energy-efficient modes of operation of AM, operating in the resources of a rational electric drive, it is necessary to determine the numerical values of the parameters of the AM equivalent circuit, the currents flowing through the circuit element. There is no significance to this important definition of squirrel-cage currents, in accordance with the identification of the allocation of squirrel-cage rotor currents, which requires a solution along with the determination of the parameters of the IM equivalent circuit.METHODS. To analyze the work of AM in technical and educational formulations, equivalent circuits are presented, which turn into circuits with serial and analytical connections of active and inductive connections. For the established and transient operating modes of AM, it is important to determine the stator and rotor currents, their active and reactive components. In this regard, it is proposed to present the IM equivalent circuit in the form of conductivities connected in parallel, which will allow determining the components of IM currents without complex mathematical models. The replacement circuit of AM consisting of a series and parallel connection of active and inductive resistances has been converted into a circuit consisting of conductances. When converting the AM equivalent circuit, no additional dependencies and coefficients were introduced, and all assumptions that are accepted for IM equivalent circuits refer to the circuit under consideration. RESULTS. It was decided to use the equivalent circuit of one phase of AM, expressed in terms of the conductivities of the stator and rotor. According to the found dependences of conductivities, for the proposed equivalent circuit, the corresponding currents and powers of the AM phase are determined. Formulate the basic principle of optimal frequency control of AM, according to the criterion of energy saving. As an indicator of the efficiency of AM operation in steady-state operating modes, the minimum value of the total losses of the engine, the value of which is determined by the ratio of the product of the active conductivity of the rotor circuit q2s and the active conductivity of the phase q to the square of total conductivity y.CONCLUSION. Based on the results of the analysis of the characteristics of an asynchronous motor, the following conclusion was drawn: the motor will operate with minimal losses if the amplitude of the supply voltage is changed so that the slip of the asynchronous motor is equal to the critical value sξ for a given frequency. For the investigated engine AIR100S4, the critical value is sξ=0.0613 at a network frequency of 50 Hz. The method proposed in the work allows to reduce the loss of active power by 3-5% in the motor windings.

ДОСЛІДЖЕННЯ ЕНЕРГОЕФЕКТИВНОСТІ ЕЛЕКТРОМЕХАНІЧНОЇ СИСТЕМИ ВОДОПОСТАЧАННЯ БАГАТОПОВЕРХОВОГО БУДИНКУ ІЗ ДВОРІВНЕВИМИ СТОЯКАМИ

The influence of the structure of the electromechanical water supply system of a multi - storey building on its energy efficiency is investigated. A quantitative estimate of the reduction in the efficiency of the system compared to the supply of water to the top floor, depending on the number of floors. A complex mathematical model of the system with one and two risers (asynchronous motor - pump - branched hydraulic network) with determination of parameters of operating modes taking into account the mutual influence of system components is developed. The value of the system efficiency criterion as the ratio of the potential energy of water at the consumer to the consumed energy is substantiated and quantified. The electromechanical water supply system of a multi-storey building with two levels of risers consumes 30% less energy than the system with a single riser, due to the reduction of the amount of excess pressure in consumers of lower floors. References 12, figures 3, table 1.

Effect of Barometric Pressure Fluctuations on Gas Transport over Soil Surfaces

Molar diffusion mechanism is generally considered to be the main physical process of gas transport at the soil–atmosphere interface. However, the advection mechanism in porous medium can considerably affect soil gas transport. Barometric pressure fluctuations caused by pressure pumps is one of the main factors that affects the advection mechanism. Most of the existing studies are overly focused on the construction of complex mathematical models and cannot exclude other environmental factors from interfering. In the present study, a simple attenuation form of barometric fluctuations was explored as a “minimum unit” of pressure wave in laboratory. A pressure attenuation model (PAM) was developed to verify the relationship between pressure difference and gas emission from soil surface by measuring the change in pressure attenuation. The effect of pressure fluctuations on soil surface gas fluxes was then quantified based on the calculated fluxes. In addition, the relationship between the physical properties of the soil medium and the change in pressure was also analyzed. The results show that fluctuations in air pressure can cause a change in soil CO2 fluxes by an order of magnitude (change of 1 Pa can result in approximately 100% change in flux for sandy loam). The sensitivity of different soil medium to pressure differences was positively correlated with soil gas permeability, which is the main physical property of soil that influences the response of gas to pressure fluctuations. These results provide important prerequisites for quantifying more complex pressure fluctuations in a future study.

Mesterséges neurális hálózatok az állatitermék-előállításban

The rise of artificial intelligence (AI) is not going unnoticed in the agricultural sector. The processing of the large amounts of data (’big data’) generated in animal production is increasingly being done using artificial intelligence, particularly machine learning (ML). Machine learning is a branch of AI, in which algorithms are automatically trained to solve a task of interest using a given dataset. There are several sub-areas of ML, of which we focus on artificial neural networks (ANNs), the most successfully used in agriculture. The basic units of an ANN are artificial neurons. These are connected to each other similarly to synapses in the brain, forming a network. ANNs can be considered complex mathematical models that can make predictions from given data after a learning process, taking into account millions of parameters. Because they are pretty flexible, these networks have a wide range of applications in many fields. One such field is a subset of agriculture, namely animal production. In our work, we outline the general structure and operation of ANNs. We provide insight into the metrics widely used to indicate the accuracy of prediction and their calculation methods. Possible applications are illustrated with examples specifically from the field of food production. The wide range of applications is illustrated by the fact that the works cited also respond to the challenges faced by aquacultures and beekeepers, in addition to the problems of cattle, pig and poultry farms. Despite their many good features, ANNs cannot solve all problems, regardless of type. Therefore, in our work we also concern about the limitations of the method. Our work contributes to the definition of artificial intelligence, machine learning, and artificial neural networks in the context of agriculture.

Исследование виброзащитной системы сиденья с квазинулевой жесткостью при стохастических воздействиях на элементы ходового оборудования автогрейдера

With the help of a complex simulation mathematical model of a motor grader developed in the Matlab environment, including subsystems of vibration-protective cab supports, a vibration-protective mechanism of the operator's seat, setting stochastic effects on the elements of running equipment when moving along a microrelief, a computational experiment is carried out, when processing the results of which, the influence of a number of system parameters on the root-mean-square seat acceleration deviation in the vertical direction. The variable parameters are the root mean square deviation of the vertical coordinates of the microprofile of the supporting surface, the speed of motion of the motor grader, the size of the zone of quasi-zero stiffness of the vibration protection mechanism of the operator's seat, the value of the increase in the spring stiffness coefficient of the vibration protection mechanism, which sets the slope of the average section of the static power characteristic of the vibration protection mechanism. An increase in the size of the zone of quasi-zero stiffness allows several times to reduce the average value of the root-mean-square deviation of the seat acceleration for a set of movements at various profile heights and speeds. Giving the middle part of the static characteristic a small slope also allows a slight decrease in the average value of the standard deviation of the seat.

INVESTIGATION OF THE ELABORATE DYNAMICS OF WEAKLY NONLINEAR FRACTIONAL ION-ACOUSTIC WAVES IN MAGNETIZED ELECTRON–POSITRON PLASMA

This study employs three advanced computational and numerical techniques to solve the nonlinear fractional modified Korteweg–de Vries–Zakharov–Kuznetsov (mKdV–ZK) equation in magnetized plasma. The reductive perturbation approach is utilized to investigate the dynamics of various components, namely isothermal species, immobile background species, and warm adiabatic fluid, in magnetized plasma. Emphasis is placed on unraveling the asymmetrical propagation characteristics of nonlinear electrostatic waves. The model’s solutions encompass diverse types of solitons, including ion-acoustic, dust acoustic, and electron acoustic solitons. Analytical solutions are obtained using a variety of mathematical functions, such as exponents, trigonometry, and hyperbolas. Two- and three-dimensional density graphs illustrate the practical behavior of a single soliton. The primary objective of employing numerical schemes is to assess the accuracy of the derived solutions, and the outcomes demonstrate the efficacy of the analytical method in solving nonlinear mathematical and physical problems. Several techniques are employed to validate the consistency between calculated and estimated results, ensuring the study’s accuracy and reliability. Overall, this investigation underscores the effectiveness of numerical and analytical techniques in tackling complex mathematical models, offering a promising avenue for future research in the field. The findings carry significant implications for comprehending nonlinear phenomena in magnetized plasma and contribute to advancing the field.

Bionics in architecture and geometric modelling of thin shell surfaces

In the scientific problem of design and calculation of thin elastic shells in the modern world, certain advances have already been made in mathematical and technical theory, based on hypotheses, experimental data, calculation equations and engineering calculations. Only such shells, which are designed based on calculation and used in building and technical constructions, can be referred to a small number of geometric surfaces. When designing thin shells, surfaces of rotation (sphere, torus, paraboloid, ellipsoid of rotation) and transfer surfaces (hyperbolic and elliptic paraboloid, circular transfer surface) are used. Trends in construction and engineering seek to apply complex mathematical models in harmony with environmental policy and the environment. This leads to the necessity of studying the influence of parameters when modeling an object on the parameters and properties of the created construction. Possessing a more complex shape the shells are realized as a result of experiment. As a result of active introduction of information technologies it became possible to introduce cardinally new methods in the application of geometric thin-walled spatial structures for the design of building and technical constructions, a number of machine-building parts. Modern analytical calculation programs and computer-aided design systems (Compass, Autocad, Archicad, etc.) make it possible to create a geometric projection model of a structure on the basis of primitives, to perform structural and static calculations of a project in an elementary manner. The solution of such layout problems is made possible with the support of computer geometry based on descriptive and analytical geometry, linear and vector algebra, mathematical analysis, and differential geometry. Modern bionics and environmental policy relies on the latest methods of mathematical modeling of architectural projects with a wide choice of computational and graphical software for calculation and 3d visualization.

Numerical analysis of fractional heat transfer and porous media equations within Caputo-Fabrizio operator

<abstract><p>This paper presents a comparative study of two popular analytical methods, namely the Homotopy Perturbation Transform Method (HPTM) and the Adomian Decomposition Transform Method (ADTM), to solve two important fractional partial differential equations, namely the fractional heat transfer and porous media equations. The HPTM uses a perturbation approach to construct an approximate solution, while the ADTM decomposes the solution into a series of functions using the Adomian polynomials. The results obtained by the HPTM and ADTM are compared with the exact solutions, and the performance of both methods is evaluated in terms of accuracy and convergence rate. The numerical results show that both methods are efficient in solving the fractional heat transfer and porous media equations, and the HPTM exhibits slightly better accuracy and convergence rate than the ADTM. Overall, the study provides a valuable insight into the application of the HPTM and ADTM in solving fractional differential equations and highlights their potential for solving complex mathematical models in physics and engineering.</p></abstract>

Application of simulation methods on vibration analysis of a bus driver seat using the quarter car 3DOF model subjected under harmonic excitation

Vibration of bus driver's seat subjected under harmonic excitation, 3DOF (3 degrees of freedom) dynamic model is employed to carry out the calculation by 3 simulation methods. Mathematical model - numerical using Matlab programming language (Numerical model), Multi Body Dynamics (MBD) using Matlab Simmechanics tool (MBD model) and finite element model using Ansys APDL (FEM model) are employed. The strengths and limitations of each method are analyzed through the process of building models and retrieving the resulting data. The evaluation indexes include the response of driver's seat acceleration, response of the seat suspension's relative displacement and the seat suspension's vibration isolation ability according to two investigated cases of natural frequency and damping ratio. The obtained results from all 3 methods have no difference and the evaluation indexes are suitable according to the studies on vehicle vibration response. The Numerical model method requires the user to perform complex mathematical modeling. The MBD model method using Matlab Simmechanics is simpler, using built-in function blocks, requiring declarations to establish the exact initial equilibrium position of the mass elements. The FEM model method using Ansys APDL with keypoints and lines describing the model elements requires precise setting of the displacement of each keypoint. However, both the MBD and FEM model methods are only effective when investigating the response in the time domain for a particular instance of the excitation frequency. When analyzing the response in the frequency domain, which requires accessing and synthesizing data of many cases in the investigated frequency range, these two methods have many limitations in the calculation process, specifically, in performing complex computations with many loops and variables. Solving problems also takes longer than numerical method using mathematical model. The obtained results are analyzed in the time domain, frequency domain, and the value domain of the driver's seat suspension parameters. This result serves as a basis for developing the design of the driver's seat suspension system with nonlinear spring and shock absorber, and the selection of a calculation method suitable for each problem in the field of vehicle vibration.

PECULIARITIES OF THE PV-MD PHOTOMODULE STRUCTURE FORMATION DURING THE ELECTRICAL ENERGY AND DISTILLATE PRODUCTION

The operating conditions of the photomodule are largely determined by the thermal regime, which affects the efficiency of electricity generation. The use of a forced cooling system in the photomodule with the implementation of the salt water distillation process allows you to control the thermal regime and obtain an additional product in the form of fresh water. The choice of the method of controlling the cooling process and the mode of its implementation makes it possible to achieve a rational combination of electrical and technological productivity of the photomodule. In this paper, analytical studies of the formation of the temperature field of the absorber of the hybrid solar collector (PV-MD) during cooling due to the evaporation of the heat carrier and recovery of the heat of the formed steam were carried out. The research method makes it possible to analyze the characteristics of the PV-MD collector, namely, the heating temperature of the absorber and coolant, as well as the performance of the distillate system, depending on the structure of the module and its operating conditions. The aim of the work is to develop a method for calculating the thermal performance characteristics of the hybrid solar collector in the conditions of a cascade method of heat and mass transfer of salt solution and distillate and to identify the rational architecture of the device. A complex mathematical model of local analysis of heat and mass exchange processes of a hybrid solar collector for real solar and climatic conditions is used. The analysis of heat and mass transfer in variant conditions showed that the degree of uniformity of the absorber temperature field, which depends on the efficiency of electricity production, when applying the PV-MD method is the same as for the PVT method. Cascade recovery of thermal energy using the PV-MD method for collectors of typical sizes is limited in efficiency to two stages. The generalized dependences for determining the technological productivity of the two-stage PV-MD collector in terms of distillate and absorber temperature when the external operating conditions of the collector change, which can be used to evaluate the efficiency of converting solar energy into a technological product, have been obtained.

COMPLEX MATHEMATICAL MODELING FOR ADVANCED FRACTAL–FRACTIONAL DIFFERENTIAL OPERATORS WITHIN SYMMETRY

Non-local operators of differentiation are bestowed with capabilities of encompassing complex natural into mathematical equations. Symmetry as invariance under a specified group of transformations can allow for the concept to be applied extensively not only to spatial figures but also to abstract objects like mathematical expressions which can be said to be expressions of physical relevance, in particular dynamical equations. Derived from this point of view, it can be noted that the more complex physical problems are, the more complex mathematical operators of differentiation are required. Accordingly, the fractal–fractional operators (FFOs) are expanded into the complex plane in our research which revolves around a unique class of normalized analytic functions in the open unit disk. To bring FFOs (differential and integral) into the normalized class, the study aims to expand and modify them along with the investigation of the FFOs geometrically. The qualities of convexity and starlikeness are implicated in this study where the differential subordination technique serves as the foundation for the inquiry under consideration. Furthermore, a collection of differential FFO inequalities is taken into account, demonstrating that the normalized Fox–Wright function can contain all FFOs. Besides these steps, the concept of Grunsky factors is applied to investigate symmetry, while boundary value issues involving FFOs are probed. Consequently, the related properties and applications can be further developed, which requires the devotion to differential fractional problems and diverse complex problems in relation to viable applications, pointing out the room to modify and upgrade the existing methods for more optimal outcomes in challenging real-world problems.

THEORETICAL BASIS FOR ADVANCED SOLUTIONS OF HIGH RPM ELEMENTS OF CIVIL AND MILITARY MACHINES BASED ON STRENGTH AND DYNAMIC STABILITY CRITERIA

In modern conditions, one of the significant obstacles to ensuring increased power, efficiency and resource of military and civilian vehicles is the exhausted possibilities of traditional technical solutions of basic elements and systems. This primarily applies to high-speed elements, in particular, turbines and rotary parts of air blowers of internal combustion engines, transmissions, drives, hydraulic machines and more. High speeds cause dynamic processes that can potentially lead to problems with strength, rigidity and stability. In order to substantiate the progressive technical solutions of high-speed parts, it is necessary to develop appropriate theoretical foundations for the analysis of processes that occur in these elements. The stress-strain state of the elements of rotor systems is of particular interest. It is also important to determine the stiffness properties of the elastic supports. In turn, this affects the stability of the rotor systems. This creates a basis for establishing patterns of influence of variable parameters on the characteristics of dynamic processes and states. A complex mathematical and numerical models of the stress-strain state and stability of motion of high-speed structural elements is developed on a unified methodological basis. These models are described by a common set of varied parameters. General criteria and restrictions are formulated. The search for advanced solutions is carried out by meeting certain complex criteria and constraints. Design parameters and operational modes are varied. The analysis problems are solved using a unified parametric model. Keywords: civil and military machines, RPM structural parts, stress-strain state, critical rotational velocity

Динамические свойства сиденья автогрейдера с квазинулевой статической характеристикой

During operation, transport and technological machines and equipment experience significant vibration effects from the working environment, which are transmitted to the human operator through the cab seat. The negative impact of dynamic influences and vibrations transmitted through the seat to the operator is noted in many works. The use of vibration protection systems for operator seats requires their simulation and study on mathematical models, which is an urgent task in the design of such systems. Vibration protection systems with the effect of quasi-zero stiffness are promising. To study vibration protection systems with quasi-zero stiffness, a complex simulation mathematical model of a motor grader was developed, the movements of which are of a spatial nature. The model includes subsystems of supporting elements of the base chassis, vibration-proof supports of the operator’s cabin, and, finally, the vibration-proof mechanism of the operator’s seat. The last subsystem makes it possible to study vibration protection mechanisms with a given size of the zone of quasi-zero stiffness in the static force characteristic. Using the developed complex simulation model, the system’s responses to step actions exerted on the elements of the running equipment of the base chassis of the motor grader were studied. The effects on one of the wheels of the front balance axle and one of the wheels of the rear balance bogie of the motor grader were investigated. Two static power characteristics of the vibration-protective seat system were considered, one of which had a section of quasi-zero stiffness, and the second did not. According to the results of the computational experiment, it was established that the vibration protection system with a quasi-zero stiffness section provides maximum seat accelerations that are ten times less than a vibration protection system without a quasi-zero stiffness section. This confirms the promise of using vibration protection systems with the effect of quasi-zero stiffness.

DETERMINATION OF INTERVALS REGARDING POSSIBLE VALUES OF CHARGE PARAMETERS WHEN PRODUCING FERROALLOYS

The energy performance of the ore-thermal furnace is affected by the electrical and thermal parameters of the charge, which vary depending on its composition and heating temperature. Namely: specific electrical resistance (SER), mass heat capacity, specific density and coefficient of thermal conductivity. Many scientists experimentally established the mathematical dependence of these parameters on temperature. However, in order to ensure the adequacy of the complex model of the ore-thermal furnace in the mode of its adjustment for a specific process, it is necessary to determine the intervals of possible values of the specified parameters of the charge loaded into it. In the future, the optimization problem considers all possible combinations of their discrete values within the previously mentioned limits, and the one of them that provides the minimum prediction error of the model is determined. If we consider the charge as a whole, then the intervals of the value of the specific electrical resistance depending on the temperature range from 2.055 to 9.249 Ohm·m at low temperatures and from 0.002 to 0.018 Ohm·m in the range of 1200-13000С, depending on the percentage composition of its components. The largest fluctuations in the thermal conductivity values of the charge are present in the temperature range from 500 оС to 900 оС and are 0.754—1.93 W/m·оС. The largest fluctuations in the heat capacity values of the charge are characteristic of high temperatures. Among other input parameters of the complex model of the operation of the ore-thermal furnace, there is also the bulk density of the charge, which also has its fluctuation limits, but only the limits of its components are known. The formula for calculating the density of the charge as a whole is proposed and its maximum and minimum values are established. The obtained information is sufficient to carry out more accurate technological calculations regarding the specified properties at different temperatures and components of the charge from which certain grades of ferroalloys are smelted. Therefore, in order to set an optimization problem regarding the minimization of the possible forecast error of the proposed model, it is possible to determine their specific oscillation intervals. In the further selection of the parameter values, they will be used as input data in the complex mathematical model of the ore-thermal furnace operation, which makes it possible to dynamically monitor the electrical and thermal processes that are directly related to each other and occur during the smelting of ferroalloys.

Synergy of Investment Projects: A Cognitive Approach

An important part of the analysis of economic growth of regions is the study of the investment distribution within industries and Russian Federation regions. Carefully considered construction of extra value sequences can create positive impulses because of the synergetic effects of investment projects. The purpose of the study is to analyze the synergetic effects of regional investment projects and impulse modeling their effects on Russian economic system. Finding such effects requires complex mathematical models implementation, and usually it cannot describe all existing investment relationships. Cognitive modeling methods can become the solution of stated problem. Cognitive modeling is a combination of mathematical approaches and expert assessments. The following study includes multidimensional factor statistical analysis, which was applied to construct a cognitive map for impulse modeling. Based on investment projects in Russia, there were identified 4 main generalized economic factors. These factors were sets of closely interrelated industries. Complied factors were energy and chemical industry, mining and processing of minerals and mechanical engineering, quality of life, metalworking and woodworking. four main scenarios of investment impulses in the constructed factors were also evaluated. The growth of investment flows in the “quality of life” factor was chosen as the optimality criterion. It was revealed that the development of metal- and wood-processing provides the biggest positive effect. The conducted research shows the importance of investment synergy studying and describes a methodological approach to perform calculations.

Optimization of Multi-Product Aggregate Production Planning Using Improved Genetic Algorithm

Medium-term production planning with aggregate production planning (APP) is a crucial step in the manufacturing industry's supply chain. The essential phase determines the production size of each product over a planning horizon. Poor planning will undoubtedly directly impact the company regarding production costs and profits. The aggregate production planning is classified as NP-Hard combinatorial problem. Thus, a powerful approach is required. Most models in aggregate production planning consider a single product. This study modeled aggregate production planning to address a multi-period and multi-product. Thus, a more complex mathematical model is required. Implementing genetic algorithms (GA) may solve the problem with reasonably good solutions. This study aims to improve the GA by applying real-coded chromosomes and the adaptive change of crossover and mutation rates based on predetermined change criteria. The planning produced by the modified genetic algorithm is compared to the manufacturer's actual planning to prove the proposed approach's effectiveness. A set of computational experiments proves that adaptive evolution enables the genetic algorithm to balance its exploration and exploitation ability and obtain better solutions. The modified GA produces a less fluctuating pattern of the production amount. Even though the modified GA yields more inventory cost, the high cost of recruiting new workers can be eliminated. Using the proposed approach, the company can reduce 9 percent of the production cost.

Modelling and Simulation Hydrodynamics Processes in Liquefied Natural Gas Transportation Systems

Global natural gas resources are growing and are increasingly geographically diverse. A Floating Storage and Regasification Unit (FSRU) is one of the most commonly used vessel types in the global ship fleet due to the possibility of storage, reloading to another ship, and regasifying it for re-injection into the natural gas grid. It is important to control system parameters for reliable technological processes such as tank hydrostatic pressure, vapor pressure, LNG density, LNG temperature, and phase changes between liquid and gas states. Additionally, pressure monitoring is important to control during transit in port and bunkering to prevent the pressure in the tanks from exceeding the tank design pressure. In this research study, a comprehensive hydrodynamic model for an LNG storage tank in a real-life regasification terminal (Floating Storage and Regasification Unit, LNG Terminal of Klaipeda City, Lithuania), operating in transportation mode to the regasification unit, was created. For this research, LNG is investigated as a compressible liquid and the speed of sound in LNG is evaluated. A complex mathematical model of the system allows the analysis of high-speed hydrodynamic and dynamic processes at cryogenic temperature (110 K) and evaluates the geometric parameters (tank geometry, electric motors and pumps, pipe geometric parameters, and roughness of internal surfaces) and the characteristics of pumps and electric motors. The complex mathematical model of the system was implemented using Fortran programing language and MATLAB R28a. It determined the parameters (pressure, velocity, liquid level of LNG in the tanks, electric motor angular velocity, torques, hydraulic energy losses, etc.) of the system during its start-up mode (until 5 s). It was found that hydraulic energy losses in all pipes contain 1.7% of the whole system power (the total power of the electric motors is 3132 kW). In case of increasing energy costs, this model could be used to control energy losses during the operation of the FSRU in various technological modes.

Self-tuning Process of the Control Laws of the Aviation Gas Turbine Engine

The article is devoted to the selection of parameters and evaluation of the efficiency of an aviation engine based on a system approach, when the engine and power plant are considered as subsystems of a higher-level aircraft complex. To solve the problems of multiparameter optimization, complex mathematical models of the entire system, consisting of the aircraft and control systems, taking into account the properties of the used fuels, are developed. The integration of the aircraft engine and the aircraft is carried out on the basis of the conditions for ensuring mass balance, the volume layout of the starting thrust-mass ratio. In combined power plants, it is possible to consider engines of different types, for example, TPrE with parallel or sequential (tandem) arrangement of circuits, TRBEaf and ramjet and steam hydrogen rocket-turbine engines of several types, the parameters of the working process of which are optimized according to the conditions of a typical program flights The adaptation task can be solved by changing both control programs and parameters of intellectual regulators of individual subsystems, as well as the structure of individual subsystems and connections between them. The higher level determines which strategy and which adaptation algorithm to choose in this situation. The optimal behavior model of the system in the current situation is also determined here. At the next level (the level of the technological complex), a strategy for the integration of the control and planning systems of the gas station, technological equipment and information system is formed, depending on the modes of operation of the gas station and the fulfillment of the tasks set before it. The construction of the ACS GTE model in the VisSim modeling software package was completed, measures were taken to stabilize the system. The transfer functions of the main elements of the electronic automatic control system of the GTE were obtained: a speed sensor, a thermocouple, and a pressure sensor. sensor of the angular position, the actuator mechanism of the nozzle-valve, the movement of the aircraft by the pitch angle.

Determination of the optimal parameters and engine layout for a strike unmanned aerial vehicle

The article describes the solution of a complex problem to determine the optimal parameters and engine layout for the power plant of an advanced unmanned aerial vehicle according to the methodology developed by the authors using the authors complex mathematical model and the well-known method of indirect statistical optimization based on self-organization. At the same time, the main aerodynamic and flight performance characteristics of the unmanned aerial vehicle under study, calculated according to engineering methods, are shown, as well as the parameters and characteristics of its power plant, calculated using the authors algorithm implemented in a complex mathematical model. The results of parametric studies are also presented using the example of assessing the influence of the bypass ratio on the characteristics of a power plant and the parameters of the unmanned aerial vehicle under study. The process of conducting optimization studies of the Unmanned aerial vehicle power plant system with a bypass turbojet engine with mixing of the circuit flows behind the turbine is described. At the same time, special attention is paid to the formulation of the optimization problem, the choice of criteria and changeable variables, as well as the analysis of the results obtained by comparing the efficiency of the system under study with different engine configurations according to the criteria of the aircraft level: maximum range according to two formed flight programs.

Designing PID Controller Using improved Differential-Pole-clustering Approach of Model Order Reduction Techniques

The method of mathematical modelling that takes into account various physical systems, such as various tele-communications, High voltage transmission, and various chemical reactors, ultimately produced a variety of solutions for bigger order complex mathematical models with higher order. Order reduction is essential for such higher order systems (HOS) for reducing mathematical complexity for designing controllers. In order to improve upon several existing model order reduction approaches, the goal of this paper is to solve difficult higher order models using Differential Pole Cluster Mixed (DPM) Techniques. The accuracy of the proposed reduced model has been made via comparing step responses of original and reduced order models. In order to improve upon several existing model order reduction approaches. The higher order system PID Controller has been made using the proposed reduced-order approach.