Power Engineering Research Articles

Speed controller design for turboshaft engine using a high-fidelity AeroThermal model

Abstract One of the main objectives of this research is to construct a high-fidelity aerothermal model for controlling the turboshaft engine power turbine rotational speed. Firstly, a high-fidelity aerothermal model of General Electric T700 is formed. The turboshaft engine aerothermal model is simulated and compared to engine design point data on MATLAB/Simulink environment. Thermodynamic equations and some algebraic equations are used. In predicting compressor mass flow rate, the adaptive neuro-fuzzy inference system method is preferred. A propeller model is also added to the turbo shaft engine aerothermal model and to keep the power turbine rotational speed at a constant value, a Proportional Integral Derivative controller is designed and applied. Open-loop and closed-loop simulations are conducted and successful outcomes are achieved. Results indicate that the differences between simulation and actual engine data are within acceptable limits. The suggested model can be readily updated and expanded to control additional parameters of the engine. PACS 2010 Classification: Control theory in mathematical physics, 02.30. Yy, Computer modeling and simulation, 07.05.Tp, 05.70.Ce Thermodynamic functions and equations of state.

Effect of Project-Based Learning Model on Creativity and Learning Outcomes of Basic Electrical Engineering

This study aims to determine the effect of project-based learning models on creativity and learning outcomes of Electrical Installation and Power Engineering students in the Basic Electrical Engineering subject in class XI of SMKN 1 Airmadidi. This study used an experimental method with a post-test-only control group design. The instruments used included learning outcome tests and creativity questionnaires. The results showed a significant difference in the learning outcomes of Basic Electrical Engineering between students who were involved in learning using project-based models and those who followed conventional methods. This indicates that applying project-based learning models substantially affects the learning outcomes of Basic Electrical Engineering in Class XI of SMKN 1 Airmadidi with a ttable value < tcount or 4.10 < 6.773. The project-based model also shows the level of creativity between students who undergo learning with a project-based approach and those who use conventional methods. These findings indicate a significant effect of the project-based learning model on student learning creativity in Class XI of SMKN 1 Airmadidi with a ttable value < tcount or 4.10 < 6.418.

The Pervasive Impact of Software Engineering and Architecture: A Multi-Industry Analysis

This article presents a comprehensive analysis of the ubiquitous role of software engineering and architecture across diverse industries in the modern digital landscape. Through a combination of literature review, industry case studies, and expert interviews, we examine how core software engineering principles—such as scalability, security, user experience, and data management—are applied and adapted in sectors ranging from e-commerce and fintech to healthcare, transportation, media, manufacturing, and government services. Our findings reveal both common challenges and industry-specific innovations in areas such as blockchain technology, telemedicine, autonomous vehicles, and industrial IoT. We also explore emerging trends, including the integration of artificial intelligence, edge computing, and quantum computing, and their potential impact on future software architectures. Furthermore, this article addresses critical ethical considerations and societal implications, including data privacy, job displacement, and the digital divide. By synthesizing these multifaceted perspectives, we provide valuable insights for both industry practitioners and academic researchers, highlighting the transformative power of software engineering in shaping the technological foundations of contemporary society and identifying key areas for future research and development.

Behavior of the Electricity and Gas Grids When Injecting Synthetic Natural Gas Produced with Electricity Surplus of Rooftop PVs

Distributed generation and sector coupling are key factors for economic decarbonization. Because gas networks have a large storage capacity, they have attracted the attention of power engineers to use them to increase the flexibility and security of supply in the presence of renewable and distributed energy resources. This paper makes the first attempt to integrate the electricity and gas systems to fill available gas storage facilities with synthetic natural gas on a large scale. This synthetic natural gas can then be used to operate gas turbines and to compensate for the fluctuating production of renewable energy sources. The LINK-holistic architecture, which integrates renewable and distributed energy resources, is used in this work. It facilitates sector coupling, which means power-to-gas and gas-to-power, throughout the entire power grid and at the customer level. This work is limited to investigating the power-to-gas process at the prosumer level. The electricity surplus of rooftop PVs is used to produce synthetic natural gas, fed into the gas grid after covering the local gas load. The behaviors of the electricity and gas grids are investigated. Results show that electricity prosumers may also become prosumers of synthetic natural gas. The current unidirectional gas grids should be upgraded with compressors at pressure reduction groups to turn them bidirectional, allowing synthetic natural gas storage in the existing large gas storage appliances after considering the pipes’ linepack effect. The proposed solution could make it possible to fill the underground storage plants in summer, when the electricity and synthetic natural gas production exceed electrical and gas demand, respectively.

Exploring the role of nanoparticle additives in reducing emissions in compression ignition engine

The paper discusses the growing environmental issues caused by vehicle emissions, leading many countries to tighten their emission standards to reduce the harmful gases released by motor vehicles. This is especially important as urbanization has increased, leading to more consumption of petroleum products. As a result, there is a growing need for cleaner, more sustainable fuel alternatives. Biodiesel has been recognized as a potential solution since it is renewable, non-toxic, and less environmentally harmful than traditional diesel. The study in question explores how adding biodiesel and nanoparticles affects diesel engine performance, particularly in terms of noise and particulate matter emissions (small particles of pollution). The research was carried out using a compression ignition engine (like those found in diesel vehicles) under constant RPM (revolutions per minute) and variable loads (changes in engine stress or power requirements). The results showed that when biodiesel was blended with nanoparticles and used as fuel, there was a noticeable reduction in noise levels, carbon dioxide (CO2), and particulate matter emissions compared to regular diesel. This suggests that biodiesel, especially when enhanced with nanoparticles, can effectively lower the harmful effects of diesel engines on the environment, offering a greener and quieter alternative.

Assessment of the Carbon Footprint of Production of Construction Materials Used in Hydrogen Energy

The results of the analysis of production of construction materials used for manufacturing hydrogen life cycle equipment are presented. The aspects of the life cycle of the main construction materials (steel, aluminum, nickel, copper, titanium, platinum, carbon plastics) used in hydrogen power engineering are identified. The results of the carbon footprint assessment for the production of these materials are presented depending on the production technologies, the energy source used and the secondary raw materials. It is established that in the development of a hydrogen gas turbine unit (GTU) the main contribution to carbon footprint is made by titanium (50,9 %) and nickel (37,6 %) alloys, in spite of the fact that more than 50 % of GTU consists of steel. It has been determined that in the production of solid-polymer fuel cells the main contribution to the carbon footprint is made by the smallest construction materials — platinum (78,1 %) and carbon plastics (15,7 %) due to the fact that they have the largest carbon footprint per kg of produced material.

Protection of Nuclear Power Plants from Fraudulent Items

At present a lot of problems with fraudulent items occurred. They disrupt the safety of industry, power engineering and other objects that are important for the life of human society. The article gives infor-mation on causes of occurrence of fraudulent items in nuclear power plants and shows that protection against fraudulent items needs to perform during the whole supply chain of critical items. In detail, it concentrates to the quality of awarding terms of references, which nuclear power plant operator prepares when it gives order to commercial supplier and of process of take-over control of the deliver commodity. Due to national security, the safety of nuclear facilities is also supervised by national nuclear regulatory body. During our research we processed checklists by which national nuclear regulatory body can reveal risks in awarding the contracts to commercial suppliers and in take-over control, and ensures improve-ment of these processes.

Identification of incipient cavitation in control valve

Control valves as important elements in hydraulic systems are used to transport liquid and gaseous media, for example, water, water vapor, and hydrogen. They are mainly used in the power engineering, chemical industry, and so forth. Due to their large dimensions, the verification of hydraulic parameters is problematic. In the case of liquid flow, cavitation can occur, which is mainly characterized by noise, vibrations, or changes of hydraulic parameters. During the incipient cavitation in the valve, there are no noticeable changes in the hydraulic characteristics. The article, therefore, deals with the methodology of determining the cavitation by measuring and evaluating the characteristics of the valve, spectral analysis of noise, and vibrations during water flow. Mathematical modeling is also a suitable tool for determining the extent of cavitation in valve design. Newly created modified cavitation model, where the flowing medium is defined as a mixture of incompressible water and compressible gases (vapor and air), better corresponds to physical principles than the two-phase approach (water and vapor) with experimentally modified density and viscosity. Measured noise and vibration frequency characteristics and mathematically modeled pressure frequency characteristics identify cavitation in the (1 to 10) kHz range. The article proves that when identifying cavitation, the method of measuring hydraulic characteristics fails, but the method of measuring noise and vibrations is suitable in practice, i.e., in real industrial equipment, and the modified cavitation model is suitable for identifying cavitation regions in structural designs of the hydraulic elements.

АНАЛИЗ ПРОИЗВОДИТЕЛЬНОСТИ ХМЕЛЕСУШИЛКИ С ЧАСТИЧНОЙ РЕКУПЕРАЦИЕЙ ТЕПЛОВОЙ ЭНЕРГИИ

Drying is an integral part of the technological process of commercial hop production. Depending on the production volume and the level of automation of the process, there are several ways to dry hop cones, including convective, microwave and sublimation. At the same time, dryers have different ratios of quality and productivity. Reducing energy costs for drying hops is an important area in the development of hop growing. In this regard, modernization and analysis of the productivity of hop dryers is a pressing issue in the current conditions of rising production costs. The aim of the research is to analyze the productivity of the MXS-25 hop dryer, modernized by installing a heat pump in the air circulation circuit and having adjustable heat recovery. The air temperature in the drying chamber was successfully controlled in the range of 60 ± 2 ° C. The preheating time required to achieve the air temperature was approximately 0.5 hours, which corresponds to approximately 5% of the total hop drying time. Comparison of the measured and calculated energy consumption values showed that the experimental values were in the range of 10.2 kWh to 11.5 kWh, averaging approximately 10.85 kWh during the experiment. Accordingly, the calculated values were in the range of 8.9 kWh and 10.2 kWh, averaging 9.55 kWh. A series of experiments comparing the drying performance using partial recovery showed that with an increase in the ambient temperature to 24 °C, the maximum relative moisture separation rate reached 6.23 kg/(kWh) with a bypass ratio of 0.86, which was higher than that of 5.54 kg/(kWh) for drying with full recovery. The partial heat recovery system is superior to the full recovery system in terms of energy efficiency and increased hop drying performance.

Study on the Ratio and Model Test of Similar Materials of Heavily Weathered Granite

To study the bearing characteristics of rock-socketed single piles on the southeast coast of Fujian Province, we conducted similar material ratio tests and single pile model tests. Initially, based on the mechanical parameters of strongly weathered granite, 10 groups of similar material samples were prepared using iron concentrate powder, barite powder, and quartz sand as aggregates, with rosin and alcohol as the cementing agents and gypsum as the modulating agent. Through triaxial testing and range and variance analysis, it was determined that the binder concentration has the most significant impact on the material properties. Consequently, Specimen 1 was selected as the simulation material. In the model test, the strongly weathered granite stratum was simulated using the ratio of Specimen 1. A horizontal load was applied using a pulley weight system, and the displacement at the top of the pile was measured with a laser displacement meter, resulting in a horizontal load–displacement curve. The results indicated that the pile foundation remained in an elastic state until a displacement of 2.5 mm. Measurements of the horizontal displacement and bending moment of the pile revealed that the model pile behaves as a flexible pile; the bending moment initially increases along the pile length and then decreases, approaching zero at the pile’s bottom. The vertical load test analyzed the relationship between vertical load and settlement of the single pile, as well as its variation patterns. This study provides an experimental basis for the design of single pile foundations in weathered granite formations on the southeast coast of Fujian Province and aids in optimizing offshore wind power engineering practices.

Optimal control theory for maximum power of Brownian heat engines

Optimal control theory for maximum power of Brownian heat engines

Rediscovering paternalistic leadership: a powerful engine for startup

ABSTRACT This study investigates the effects of paternalistic leadership, a predominant leadership style in Confucian-influenced East Asia, on the growth and innovation of start-up companies, particularly within the information technology sector. Contrary to the prevailing belief that paternalistic leadership stifles innovation, our findings reveal that this leadership style can significantly enhance business performance. This study identifies key mechanisms, such as fostering employee loyalty, improving decision-making processes, and encouraging proactive behaviours, that drive growth under paternalistic leadership. Empirical evidence shows that employees under such leadership exhibit entrepreneurial behaviours marked by innovation, risk-taking, and initiative, leading to measurable improvements in profitability, customer satisfaction, and market share. These results underscore the role of paternalistic leadership in accelerating the success of East Asian start-ups and provide valuable insights for organisations seeking to balance cultural leadership styles with the demands for innovation.

Study of the features of angular stabilization of spacecraft with flexible struc-tural elements with the use mobile control methods

The development of space power engineering is one of the well-known lines in rocket and space science and innovative technologies which attracts the attention of many scientists and researchers. Engineering solutions in space-based solar power plant design and wireless space-to-Earth and satellite-to-satellite power transmission and power spacecraft control methods have been substantiated theoretically to sufficient depth. However, despite this, there is a need to improve methods for and approaches to the development of an optimal design methodology for power spacecraft. A way to improve existing approaches to the development of space-based solar power plants and power satellites may be the use of mobile control methods in the development of an attitude and orbit control system. Such methods allow one to reduce power consumption for control operations. The goal of this paper is to study the features of mobile control and construct a methodology for the development of solar power satellites’ attitude and orbit control system (AOCS) using mobile control algorithms. The paper considers the features of mobile control algorithm synthesis for the attitude control and stabilization of solar power spacecraft (solar power plants and power satellites). Power spacecraft control tasks are classified, and the expediency of using mobile control methods is justified. An analysis is made for the stability problem that arises in controlling power spacecraft with flexible elements. The paper presents methodological recommendations on determining the AOCS design parameters for space-based solar power plants and power spacecraft for wireless satellite-to-satellite power transmission. This methodology may be used in power satellite development.

On Hysteresis In A Variable Pitch Fan Transitioning To Reverse Thrust Mode And Back

Abstract A novel hysteresis phenomenon during the transition to and back from the reverse thrust mode in a Variable Pitch Fan (VPF) is identified and characterised in this work. This is done by using a three-dimensional (3D) fully transient Unsteady Reynolds averaged Navier?Stokes (URANS) with the transitioning fan blade aerofoils simulated by an adaptation of the mesh displacement method. The VPF is modelled to be transitioning in a modern 40000 lbf geared high bypass ratio turbofan engine architecture at "Approach Idle" engine power setting in a typical twin-engine airframe with the flaps, slats, and spoilers set for an aircraft touchdown airspeed of 140 knots. The transition to reverse thrust mode involves flow starvation into the engine, formation of recirculation zones in the bypass duct and the establishment of the reverse stream, all of which occurs in the opposing presence of the free stream flow at aircraft touchdown velocity. The transition back to forward flow mode involves the gradual re-establishment of the free stream which is opposed by the presence of the reverse stream within the engine. It is quantified that in the transition to reverse thrust, the blockage develops with a larger time delay than the disappearance of the blockage during the transition back due to the interplay of the temporal dynamics of fan blade motion and flow field response. The hysteresis phenomena described in this work are critical in properly developing control schedules to adapt for potential bi-stable flow field development during the landing run.

Determination of the Amount of Bilge Waste Generated by Motorized Fishing Vessels in Türkiye

When bilge water from ships is illegally discharged into the sea, it causes severe damage to the marine and coastal ecosystem. MARPOL Annex-1 does not cover many fishing vessels since it only covers vessels over 400 GT (gross tonnage). According to Turkish Statistical Institute (TURKSTAT) data, only 174 of the 14064 fishing vessels registered in Türkiye are above 400 GT. In our country, only 63 of 325 fishing harbors have waste reception facilities to control and collect bilge water. In this study, the amount of bilge waste that fishing vessels can produce was calculated using engine power information, and it was determined that a fishing vessel can produce an average of 155 L/day of bilge waste. It was also calculated that the bilge waste from fishing vessels could be at least 463872 m3/year, which is more than the 416370 m3 bilge waste collected from all vessels in 2021 according to the data of the Ministry of Environment, Urbanization and Climate Change. As a result, it is assessed that this risk can be reduced by increasing the number of waste reception facilities, the legal responsibility of waste reception facilities for bilge waste of fishing vessels, and strict inspections.

Review on high-temperature superconducting REBCO trapped field magnets

Abstract Superconducting (SC) magnets can generate exceptionally high magnetic fields and can be employed in various applications to enhance system power density. In contrast to conventional coil-based SC magnets, high-temperature superconducting (HTS) trapped field magnets (TFMs), namely HTS trapped field bulks (TFBs) and trapped field stacks (TFSs), can eliminate the need for continuous power supply or current leads during operation and thus can function as super permanent magnets. TFMs can potentially trap very high magnetic fields, with the highest recorded trapped field reaching 17.89 T, achieved by TFSs. TFMs find application across diverse fields, including rotating machinery, magnetic bearings, energy storage flywheels, and magnetic resonance imaging (MRI). However, a systematic review of the advancement of TFMs over the last decade remains lacking, which is urgently needed by industry, especially in response to the global net zero target. This paper provides a comprehensive overview of various aspects of TFMs, including simulation methods, experimental studies, fabrication techniques, magnetisation processes, applications, and demagnetisation issues. Several respects have been elucidated in detail to enhance the understanding of TFMs, encompassing the formation of HTS bulk composites and TFSs, trapped field patterns, enhancement of trapped field strength through pulsed field magnetisation (PFM), as well as their applications such as SC rotating machines, levitation, and Halbach arrays. Challenges such as demagnetisation, mechanical failure, and thermal instability have been illuminated, along with proposed mitigation measures. The different roles of ferromagnetic materials in improving the trapped field during magnetisation and in reducing demagnetisation have also been summarised. It is believed that this review article can provide a useful reference for the theoretical analysis, manufacturing, and applications of TFMs within various domains such as materials science, power engineering, and clean energy conversion.

Influence of External Clearance Variation on Vibration Characteristics of Ship Electrically Assisted Turbocharger Rotor Bearing System

Electrically assisted turbocharging (EAT) technology is an important technical means to effectively solve the problems of insufficient intake air and poor transient response of traditional turbocharged engines at low speed or acceleration, and to realize the electrification of marine internal combustion engine power system. In the EAT design stage, the original rotor model of a marine turbocharger was established and verified. Subsequently, the EAT rotor dynamics design and analysis were carried out, and the influence of the unbalanced phase and external clearance on rotor vibration was discussed. The results show that when the external clearance is small, extensive sub-synchronous vibration occurs and bifurcation occurs at high speed. When the external clearance is large, the sub-synchronous vibration component almost disappears but high synchronous vibration occurs at a high speed. At the same time, the shaft is significantly affected by the gravity load at low speeds, and the rotor makes a balanced motion on the critical limit cycle at high speed. In order to minimize the vibration and noise of the same type of EAT, it is recommended to control the outer clearance of the EAT bearing in the range of 0.30–0.36[Formula: see text]mm. The research content provides a reference for the dynamic design and analysis of the EAT, which effectively helps the development of the original engine of the ship electric auxiliary turbocharger and improves the operation stability of the EAT.

Сучасні тенденції розвитку двигунів безпілотних літальних апаратів

The subject of this study is the current state and prospects for the development of the market for unmanned aerial vehicles (UAVs) and power plants. The purpose of this work was to identify trends in the development of UAV engines of various classes. Task: collection, systematization, and analysis of information on the most common engines of reconnaissance and strike UAVs of the operational-tactical level, as well as UAVs of the "barrage ammunition" class. This article provides a brief description of various types of UAV power plants, and their main advantages and disadvantages are given, which are often decisive when choosing the type of power plant for a specific UAV. It was found that a power plant with an internal combustion engine (ICE) is best suited for use in medium- and long-range UAVs.This study demonstrated that four-stroke internal combustion engines are most commonly used in reconnaissance-strike UAVs at both operational and tactical levels. The features of the design and characteristics of four-stroke internal combustion engines, which have become the most widely used UAVs, are described. It was determined that the introduction of turbocharging or increasing the pressure is the main means of forcing four-stroke internal combustion engines, which makes it possible to simultaneously achieve high specific power and high brake efficiency of the engine over a wide range of altitudes during its operation. It is shown that one of the most important tasks for a long-range UAV engine is to reduce the specific brake fuel consumption. Thus, there is a tendency to promote the use of high-powered aviation diesels in long-range UAVs. It was determined that the main requirements for UAV engines of the "barrage ammunition" class are high specific power, low cost and adaptability to mass production. This study shows that gasoline two-stroke internal combustion engines with crank-chamber scavenging are extremely widespread in UAVs of the "barrage ammunition" class. The design features and characteristics of UAV two-stroke internal combustion engines are described. The main means of ensuring high specific power of such two-stroke internal combustion engines are increasing the engine RPM, optimizing gas exchange processes, and reducing the weight of the construction by using new materials. Conclusion. The results show that depending on the UAV type, the set of engine requirements can vary significantly. Modern trends in the development of UAV engines of various classes have been determined. Potentially promising directions for increasing the efficiency of engines and for comprehensive improvement of their indicators and characteristics have been determined.

Investigation of Onboard Power Generation Method Using Waste Energy at Altitude Conditions

Abstract Demand for increased onboard power generation on small aircraft is ever growing due to increased electrical power demand. The objective of this study is to investigate onboard power generation using waste energy at various altitude and ambient conditions. Experiments were performed on a 2-liter turbocharged direct-injection intermittent combustion engine fueled with jet fuel (F-24). The turbocharger has an integrated motor-generator system that is designed to generate electricity using the enthalpy in the engine exhaust, or to use as a motor to rotate the turbocharger using the energy stored in onboard energy storage device. An electrically actuated wastegate was used to control useful exhaust flowrate that is used to generate electricity. An external power supply system was used to emulate the energy storage. The engine was installed in the US DEVCOM Army Research Laboratory?s altitude chamber in which absolute outside air pressure was controlled up to 37.6 kPa to simulate the altitude conditions up to 7,620 m (25,000 ft). Three different ambient conditions were selected to represent International Standard Atmosphere (ISA), polar, and tropical conditions. Based on the experimental results, a response surface model was developed to predict the power generation of the motor-generator integrated turbocharger using waste energy as a function of altitude, engine power, and the wastegate position. The result from this study provides an insight into onboard power generation method using waste energy at altitude conditions.

Simulation of stainless ferritic-martensitic and austenitic steel hardening after irradiation in ion accelerator. Part 2. Development of a methodology for determining the ion mode irradiation of austenitic steels

A methodology for determining the irradiation mode for ferritic-martensitic steels at ion accelerator has been developed and experimentally substantiated, providing radiation hardening of these steels, identical to that realized under neutron irradiation. The change in Vickers microhardness is used as a measure of radiation hardening. The paper presents the results of a study of radiation-induced changes in the microhardness of austenitic steels 08Kh18Н10Т and 08Kh16Н20М2Т irradiated in reactors SM-3, VVER-440, BOR-60, SM-3 + BOR-60 to damaging doses of 10.2–33.7 dpa in the interval of temperatures 60–500°C. A study of radiation-induced changes in microhardness in a wider range of irradiation temperatures, post-irradiation annealing of irradiated steels was carried out in the range from 400 to 600°C, simulating irradiation at temperatures equal to annealing temperatures. Data are presented on radiation-induced changes in microhardness after irradiation in the ion accelerator of the State Scientific Center of the Russian Federation – Institute for Physics and Power Engineering named after A.I. Leypunsky (IPPE) with Ni+4 ions and He+ ions up to concentrations of 0–7 appm/dpa at damaging doses of 13–30 dpa and temperatures of 300–650°. A transition function has been established that connects the irradiation of temperatures during neutron and ion irradiation at a given damaging dose, ensuring the same radiation hardening of austenitic steels.