Power Engineering Research Articles

A Pressure Projection Scheme With Near‐Spectral Accuracy for Nonhydrostatic Flow in Domains With Open Boundaries

AbstractWe describe a pressure projection scheme for the simulation of incompressible flow in cubic domains with open boundaries based on fast Fourier transforms. The scheme is implemented in flow_solve, a numerical code designed for process studies of rotating, density‐stratified flow. The main algorithmic features of the open‐boundary code are the near‐spectral accuracy of the discrete differentiation and a dynamic two‐dimensional domain decomposition that scales efficiently to large numbers of processors. The simulated flows are not required to be periodic or to satisfy symmetry conditions at the open boundaries owing to the use of mixed series expansions combining cosine and singular Bernoulli polynomial basis functions. These expansions facilitate the imposition of inhomogeneous boundary conditions and allow the code to be used for offline, one‐way nesting within an arbitrarily embedded subdomain of a larger scale simulation. The projection scheme is designed to exploit a simple and powerful numerical engine: inversion of Poisson's equation with homogeneous Neumann boundary conditions using fast cosine transforms. Here, we describe the mathematical transformations used to accommodate the imposition of space‐ and time‐varying boundary conditions. The utility of the approach for process studies and for nesting within submesoscale‐resolving ocean models is demonstrated with simulations of wind‐driven near‐inertial waves in the upper ocean.

Performance of Motorcycle Fueled with Pertalite‒LDPE Pyrolytic Oil Blendings

Plastic use has expanded substantially, and its waste is primarily disposed of in landfills, which further harm ecosystems owing to inadequate waste management. Pyrolysis, which converts plastic waste into liquid fuel, is one of the potential chemical recycling alternatives for plastic. The purpose of this study is to determine the viability of using pyrolytic oil from an LDPE grocery bag as an alternative fuel for a four-stroke spark ignition motorcycle engine. The LDPE grocery bag was pyrolyzed at 500 oC at a heating rate of 3 oC/min, and the condensed pyrolytic vapor's characteristics were determined. Torque, power, and fuel consumption were investigated using a four-stroke spark ignition motorbike powered by pertalite‒LDPE pyrolytic oil blends. The results reveal that the properties of LDPE pyrolytic oil and pertalite were considerably different; hence, when the blending fuel was applied to the motorcycle, the engine torque and power decreased at low engine speed (2000‒3500 rpm), about equal at medium speed (3500‒5500 rpm), and increased at high engine speed (5500‒8500 rpm). Furthermore, the greater blending fuel greatly reduced fuel usage due to the high viscosity of the LDPE pyrolytic oil.

A Practical Guide for Noise Characterization of Back Pressure Sensors: Toward Digital Twin for an Industrial High-Horse Power Engine Test Cell

A Practical Guide for Noise Characterization of Back Pressure Sensors: Toward Digital Twin for an Industrial High-Horse Power Engine Test Cell

ОСНОВНЫЕ ЭТАПЫ РАЗВИТИЯ КАФЕДР, ВЕДУЩИХ ПОДГОТОВКУ ТЕПЛОТЕХНИКОВ И ТЕПЛОЭНЕРГЕТИКОВ В ДОНЕЦКОМ НАЦИОНАЛЬНОМ ТЕХНИЧЕСКОМ УНИВЕРСИТЕТЕ

Donetsk National Technical University, established in 1921, has become the largest center for training highly qualified engineers and scientists. The article presents the stages of development of heat engineering and heat power directions of Donetsk National Technical University at the departments of “Technical Thermophysics” and “Industrial Heat and Power Engineering”. Over the long history of the existence of the two departments, more than five thousand students have been trained. The teams of both departments continue active scientific and pedagogical activities, preserving historical traditions and continuity of scientific schools.

Взаимосвязь инновационных и классических методик профессиональной направленности обучения физике в техническом вузе

The introduction of two forms of conducting a laboratory workshop in physics for students for engineering and technology studies in the sphere of marine heat and power engineering, electrical equipment and automation means is considered to the process of studying at the Federal State Budget Educational Institution of Higher Education “Astrakhan State Technical University”. The possibility of developing students' working skills in natural conditions with industrial devices and an engineering approach taking into account the multifactorial conditions of the experiment as an independent work in the framework of the workshop of technical creativity Applied Physics organized at the Department of General Engineering Disciplines and Ground Transport is shown. The formation of the professional orientation of interdisciplinary connections of students of the specialty Thermal Power Engineering and Heat Engineering is illustrated by the example of the development of the laboratory work Determination of the specific heat capacity of metals. The advantages of virtual laboratory work and the possibility of their use on the educational portal of the “Astrakhan State Technical University”, built on the Moodle virtual learning environment, are examined. An example of creating a virtual laboratory work Studying the law of conservation of momentum is considered. It is theoretically proved that the introduction of these types of work into the educational process in physics contributes to the optimally effective formation of general professional competencies and the professional orientation of students' education. The importance of introducing these types of laboratory work into the educational process of physics at the university for the development of students' analytical abilities, creativity and innovation, which is a prerequisite for studying of modern engineers in demand in the labor market in a rapidly changing world, is shown.

Integrating Technology and Agriculture with Advanced Machinery

Abstract: Agricultural technologies are rapidly evolving towards a new paradigm – Integrating Technology. Within this paradigm, digitalization, automation and artificial intelligence play a major role in crop production, including weeding and pest control. This evolution presents both challenges and opportunities, such as leapfrogging from manual and animal-driven technologies to automated and mechanized equipment in developing countries and closing the digital divide. Traditional agricultural mechanization, characterized by the use of tractors and engine power, will be matched and even surpassed by automated equipment and robotics and the precision they can provide in farm operations. Conservation agriculture (CA) is an approach that involves crop diversification, permanent soil cover and minimal soil disturbance (e.g. limited tillage). CA increases soil structure and soil organic matter, promotes rich microbial diversity, retains water and nutrients, and better manages pests and diseases, making agricultural soils more productive and resilient to changes in climate. However, it requires specialized equipment – for example, for direct drilling of crop seed into the soil at the right depth and sowing density. Agricultural robotics can support these environmentally sustainable practices, by allowing spot weeding and precision management of nutrients, pests, diseases and weeds through mechanical removal or spot application of chemicals. Agricultural robots will also be able to substitute arduous labour, especially when there is limited availability, thus increasing social sustainability. The development of Integrating Technology will create new opportunities that can attract youth and entrepreneurs into the sector, tackling some of the causes for rural–urban migration and contributing to the economic component of sustainability.

Стендовые испытания нового уплотнения деталей цилиндропоршневой группы судового ДВС

The engine consists of a large number of parts, each of which is responsible for a specific function of its efficient operation. The reliability of a marine diesel engine is largely determined by the resource of its individual components and parts. Therefore, in order to increase the engine life, it is necessary to allocate the most responsible parts in it, which are subject to greater wear and find solutions to increase their durability. Such details include piston rings, which affect not only the technical and economic performance of the engine, but also its reliability and environmental performance. Of the entire set of sealing parts of the cylinder-piston group, the upper piston compression ring should be distinguished as the most loaded. The main function of piston rings is noted – the creation of tightness of the combustion chamber. The passage of exhaust gases is inevitable due to the presence of a “lock” in the structure, and during operation, the wear of the piston rings leads to an increase in it, which affects fuel consumption, oil, and a decrease in engine power. One of the most negative consequences of piston ring wear is the appearance of “flutter” type vibration, which leads to the destruction of not only the ring, but also the edges of the piston grooves, especially on aluminum pistons. Worn grooves are not repaired by resorting to replacing pistons. A method for extending the service life is proposed, which consists in the use of a new sealing unit for cylinder piston group parts. The new sealing unit allows you to extend the piston's operability by boring the upper piston groove of the piston until all chips are eliminated. The operability of this node and the effectiveness of the seal was confirmed by an experiment that was conducted on the stand in conditions close to real ones. A technology for restoring the operability of pistons made of aluminum alloys is proposed.

Design of Variable Valve Timing and Electronic Control for Honda R18A

Abstract: This paper explores the Variable Valve Timing and Lift Electronic Control (VTEC) system developed by Honda, focusing on its mechanisms, design methodology, and impact on engine performance. VTEC optimizes engine efficiency and power by switching between cam profiles suited for low-RPM stability and high-RPM power output, controlled by the engine's computer based on operational conditions. We examine the intricate workings of the VTEC system, detailing its hydraulic actuation and the resulting enhancements in torque and horsepower. Our study centers on the Honda R18A engine, targeting increased maximum RPM and power output. Using theoretical analysis validated through Ricardo Wave software and MATLAB simulations, we determine optimal valve lift and timing to achieve the desired performance. Additionally, the research addresses the geometric parameters influencing airflow through the valves, providing a comprehensive understanding of the VTEC system's contribution to engine efficiency and driving experience. This investigation not only underscores the technological advancements in variable valve timing but also presents practical insights for automotive engineering applications.

КАФЕДРЕ ЭНЕРГЕТИКИ ТЕПЛОТЕХНОЛОГИИ – 35 ЛЕТ

The article is dedicated to the 50th anniversary of the Department of Processes and Apparatus of Chemical Technology and the 35th anniversary of its renaming, in connection with the opening of a new specialty, to the Department of Energy engineering of heat technologie. Since 1990, the department has graduated more than three thousand specialists (engineers, bachelors, masters) for the energy sector, housing and communal services, the building materials industry, engineering and design centers. More than a third of graduates completed full-time education, and every tenth graduate received a diploma with honors. The department is implementing programs of additional professional education in the field of energy saving and increasing energy efficiency; 1,300 specialists have undergone advanced training at the department. The educational and scientific work of the department is aimed at basic heat engineering and heat and power education, energy saving and increasing energy efficiency, recycling of secondary energy resources, and the use of renewable and alternative energy sources.

ЭНЕРГЕТИЧЕСКИЙ ПЕРЕХОД И ЭНЕРГОСБЕРЕЖЕНИЕ НА НОВОМ ЭТАПЕ РАЗВИТИЯ

The problem of increasing energy efficiency in the Russian Federation is considered. The USSR energy system was unique in size and efficiency; due to large interconnected energy facilities and the development of district heating, it made it possible to efficiently consume fuel, which resulted in annual savings of 40-60 million tons of standard fuel and 10-15 GW of capacity. After a period of decline in the 90s of the last century, over the past 15 years the country's energy consumption has increased by a third, and structural changes have occurred in the main energy-intensive sectors of the Russian economy. It is noted that industry accounts for about 45% of the Russian energy balance, which is many times more than thermal power engineering (21%). The country's reserves for energy saving and energy efficiency can be divided into two groups. System reserves, consisting of an increase in the capacity and load of “carbon-free” sources - hydroelectric power stations and nuclear power plants, active use of losses and heat from technological processes, optimization of heat supply schemes, account for more than two-thirds of the potential for increasing energy efficiency. The second group consists of the use of renewable energy sources, waste, and biofuels. The country’s energy strategy should not consist in the quick payback of energy-saving projects, but in working on the systemic, multiplier effects of industrial development and infrastructure projects, the growth of large and small cities, and the development of hard-to-reach areas.

Gravitational-wave Radiation from the Magnetar-driven Supernovae

Rapidly spinning magnetars are potential candidates for the energy source of supernovae (SNe) and gamma-ray bursts and the most promising sources for continuous gravitational waves (GWs) detected by ground-based GW detectors. Continuous GWs can be radiated from magnetars due to magnetic-induced deformation or fluid oscillations, compatible with magnetic dipole (MD) radiation for spin-down energy. In this paper, we investigate the diverse light curves of magnetar-driven SNe in the scenario that the spin-down is dominated by GW radiation and/or MD radiation. By simulating the light curves of SNe and employing the Markov Chain Monte Carlo method, we constrain the parameters of the magnetars and SN explosions and show that the signature of GW radiation may be indicated by the bolometric luminosity curves of SNe Ic-BL 2007ru and 2009bb. We find that the ellipticity of magnetars in the order of 10−3 can be induced by the magnetic field of ∼1016 G. If such continuous GWs associated with SNe can be detected in the future by the Advanced LIGO and Virgo detectors, this would be a smoking gun for a magnetar engine powering SNe.

Investigation of Crack Propagation and Failure of Liquid-Filled Cylindrical Shells Damaged in High-Pressure Environments

Cylindrical shell structures have excellent structural properties and load-bearing capacities in fields such as aerospace, marine engineering, and nuclear power. However, under high-pressure conditions, cylindrical shells are prone to cracking due to impact, corrosion, and fatigue, leading to a reduction in structural strength or failure. This paper proposes a static modeling method for damaged liquid-filled cylindrical shells based on the extended finite element method (XFEM). It investigated the impact of different initial crack angles on the crack propagation path and failure process of liquid-filled cylindrical shells, overcoming the difficulties of accurately simulating stress concentration at crack tips and discontinuities in the propagation path encountered in traditional finite element methods. Additionally, based on fluid-structure interaction theory, a dynamic model for damaged liquid-filled cylindrical shells was established, analyzing the changes in pressure and flow state of the fluid during crack propagation. Experimental results showed that although the initial crack angle had a slight effect on the crack propagation path, the crack ultimately extended along both sides of the main axis of the cylindrical shell. When the initial crack angle was 0°, the crack propagation path was more likely to form a through-crack, with the highest penetration rate, whereas when the initial crack angle was 75°, the crack propagation speed was slower. After fluid entered the cylindrical shell, it spurted along the crack propagation path, forming a wave crest at the initial ejection position.

Enhancing Power System Reliability Through Advanced Fault Diagnosis Methods: A Deep Learning Approach

In order to attain high reliability in power systems, effective fault detection techniques that can quickly identify and mitigate defects must be developed. In this article, we suggest a novel method for improving power system dependability by using deep learning techniques to identify faults. In order to achieve precise fault identification and classification, our technology uses deep neural networks to automatically learn and extract features from power system data. We thoroughly test our method on a range of fault scenarios and real-world datasets to determine its efficacy. The outcomes show how well our approach performs in comparison to conventional fault identification methods, underscoring the possibility of a major increase in power system reliability. By providing useful insights for improving problem diagnosis techniques in power engineering, this research advances system resilience and minimizing downtime.

Sire: An interoperability engine for prototyping algorithms and exchanging information between molecular simulation programs.

Sire is a Python/C++ library that is used both to prototype new algorithms and as an interoperability engine for exchanging information between molecular simulation programs. It provides a collection of file parsers and information converters that together make it easier to combine and leverage the functionality of many other programs and libraries. This empowers researchers to use sire to write a single script that can, for example, load a molecule from a PDBx/mmCIF file via Gemmi, perform SMARTS searches via RDKit, parameterize molecules using BioSimSpace, run GPU-accelerated molecular dynamics via OpenMM, and then display the resulting dynamics trajectory in a NGLView Jupyter notebook 3D molecular viewer. This functionality is built on by BioSimSpace, which uses sire's molecular information engine to interconvert with programs such as GROMACS, NAMD, Amber, and AmberTools for automated molecular parameterization and the running of molecular dynamics, metadynamics, and alchemical free energy workflows. Sire comes complete with a powerful molecular information search engine, plus trajectory loading and editing, analysis, and energy evaluation engines. This, when combined with an in-built computer algebra system, gives substantial flexibility to researchers to load, search for, edit, and combine molecular information from multiple sources and use that to drive novel algorithms by combining functionality from other programs. Sire is open source (GPL3) and is available via conda and at a free Jupyter notebook server at https://try.openbiosim.org. Sire is supported by the not-for-profit OpenBioSim community interest company.

Electromechanical energy storage device

Introduction. Short-term peak loads of machines and mechanisms create the need to accumulate mechanical energy for its subsequent pulsed use. This is quite relevant, for example, for tractors at the initial stage of towing heavy trailers. The use of a mechanical energy accumulator will reduce the power of the tractor engine and expand its functionality.Target. Development of a mathematical model of a mechanical energy accumulator.Research methods. The mechanical energy accumulator can be made in the form of a direct current electric machine or a valve machine, on the shaft of which a superflywheel is attached. When a machine is connected to a power source, a non-stationary process occurs, described by two differential equations: one for mechanical quantities, the other for electrical ones. Solutions of differential equations repeat the relationships for charging and discharging an electric capacitor.Results. From the resulting formulas it follows that for an electrical circuit, the mechanical energy accumulator in question is indistinguishable from an electrical capacitor. It follows from this that in this case we can talk about artificial electrical capacitance. In addition, artificial electrical resistance arises (which is not related to the resistivity, length and cross-sectional area of the conductors). In connection with the above, a mechanical energy accumulator can be interpreted as an artificial electric capacitor, which stores not the energy of the electric field, but the kinetic energy of rotation of the superflywheel.Conclusion. There are superflywheel designs that can store significant kinetic energy. Even the possibility of installing them on passenger vehicles was studied. In this sense, massive tractors have an undeniable advantage, since the increase in weight is not only not problematic for them, but in some cases it is desirable.

Signal processing and artificial intelligence based HVDC network protection: A systematic and state-up-the-art review

In this modern era, the smart grid (SG) is progressively empowered for direct current (DC) power transmission, either at high voltage (HV) or at medium voltage (MV). The high voltage direct current (HVDC) transmission systems have a significant impact on the SG operation even though the integration of add-on green and renewable-based power generation (RPG). In this RPG era, the application of HVDC can be seen in the grid-connected remote offshore wind or photovoltaic (PV) based large RPG, and interconnections amongst the states or countries. In such a context, a smart grid inevitably is ridden with technical complexities (both control and protection viewpoints), and thus signals processing (SP) techniques along with artificial intelligence (AI) methods are considered very much important to understand, effectively plan, draw up plans, and drive the multifaceted electric power system. This paper presents an extensive review of HVDC network protection systems with special attention to SP and AI applications. This paper presents an extensive review of the suggested techniques in the past three decades and discussed the pros and cons of each method. Apart from that critical findings are discussed and analyzed along with the future scope of research toward the development of HVDC protection. This review tries to focus on the gap between the existing protection schemes and topology with the smart grid-based power system perspective and convey to the power engineers and researchers the possibilities of further research as a solution to the associated issues and challenges.

#1967 Towards the design optimisation of catheters for paediatric dialysis using a bioengineering approach

Abstract Background and Aims Central venous lines (CVLs) used for haemodialysis (HD) in children are associated with a high complication rate, leading to inadequate dialysis and need for a line replacement in nearly 45% of children on HD. This high complication rate may be due to poor CVL configurations, designed without considering specific anatomical differences between children and adults. Using a bioengineering approach, we aim to provide a fluid dynamics characterization of different CVL models commonly used in children to establish an association between CVL design and clinical complications, and to improve CVL performance by optimising their design. Method Computational fluid dynamics (CFD) using modelling and simulations is a powerful engineering tool that use computers to study complex systems, applying mathematics, physics and computer science. Four models of CVLs of varying designs and sizes (6.5Fr, 8Fr, 10Fr and 14Fr) were scanned by microCT to reconstruct computational models. CFD analyses were set up to simulate blood flow within the CVLs under both ideal and realistic models of superior vena cava. A variety of flow rates, routinely used in clinical practice, were applied to study the whole range of working conditions. Haemodynamic features that cannot be measured in vivo such as high shear stresses and large areas of stagnation, were analysed. CFD findings were compared to clinical outcomes (n = 26 patients with 57 lines) and to the blood clots distribution of CVLs removed from patients (n = 8). Fluid dynamics characteristics of the CVLs studied were used to set up a preliminary design optimisation process of a 6.5F CVL model. Using sampling methods, a variety of CVL designs were created starting from the original model and results were compared. Results In all the simulated CVLs, the arterial lumens showed the highest stagnation and recirculation areas. The role of arterial tip configuration was negligible for the blood flows and the proximal side holes played a major role for blood aspiration being also subject to the highest levels of shear stress, regardless of the design. In all the anatomical models, blood velocity increased after catheter insertion (Fig. 1a) together with wall shear stresses. CFD results were in accordance with the clinical data which showed a higher recurrence rate of thrombosis for the 8Fr and 10Fr CVLs. Also, microCT of the CVLs removed due to complications confirmed presence of thrombosis at the catheter tips. Results suggest that shear stress is the parameter most strongly related to clinical complications. The preliminary design optimisation study was used to find the parameters which have the highest influence on the CVL performance. Preliminarily optimised designs of the 6.5F model showed a better haemodynamic performance, reducing stagnation areas (Fig. 1b). Conclusion Characterisation of the fluid dynamics of commercially available CVLs explains some of the clinical outcomes experienced by patients. Identification of potential design-related complications in CVLs has allowed to set up the optimisation process which will lead to new CVL designs with improved blood flow distribution and minimal damage to blood cells. Funding Kidney Research UK, PhD fellowship and MedTech grants.

Operational data for sea margin calculations in early ship design

The current sea margin estimate applied in early ship design, commonly assumed 15-20% extra installed engine power, is not based on calculations, but has nonetheless become an industry standard. These sea margin estimations, applied in early ship design, are insufficiently accurate. This paper evaluates if a data driven approach is suitable to more accurately predict the sea margin in early ship design. Using operational data this method considers the whole operational profile of the vessel not limited to design or calm water conditions. A case study is performed where a data driven model is trained to make power predictions, subsequently this trained model is used to make calm water predictions. This proof of concept illustrates the potential of proposed method to be utilised for sea margin estimations in early ship design.

Prediction of main engine power of oil tankers using artificial intelligence algorithms

In the preliminary ship design, the accurate determination of a vessel’s main engine power is one of the most critical aspects next to service speed, main particulars, and cargo capacity. However, this task can be quite intricate due to its reliance on an extremely great number of influencing factors. In the research that is presented in this paper dataset of 357 oil tankers was gathered and developed to research the idea in which genetic programming is applied to the mentioned dataset to obtain mathematical equations (MEs) that can estimate the ship’s main engine power with high accuracy. The highest estimation accuracy of MEs is achieved by tuning the GP hyperparameter values through the random hyperparameter search (RHS) method. The initial dataset was divided into train and test datasets in a 70:30 ratio. The train dataset was used to train GP in a 5-fold cross-validation process and after the process was done the obtained MEs were evaluated on the test dataset. To evaluate the GP training testing process several evaluation metrics were used i.e., coefficients of determination (R2), mean absolute error (MAE), root mean square error (RMSE), and length of obtained MEs. The conducted investigation showed that GP generated MEs that can estimate ship main engine power with high accuracy.

Particle filter performance of soot-loaded diesel particulate filter and the effect of its regeneration on the particle number and size distribution

The DPF regeneration is crucial for reducing backpressure, minimizing negative impacts on engine power and fuel economy, but the changes in particulate emission characteristics it brings are worth studying. In this study, the influence of DPFs with different soot loadings on exhaust back pressure and particle emission characteristics, as well as the particle number emission, particle size distribution, and thermal field distribution characteristics during regeneration was investigated based on engine bench test. Results reveal that the exhaust back pressure increases linearly with the engine speed, as well as the soot loading. The increase of DPF soot loading leads to a considerable increase in the reduction efficiency of particle number (PN) and particulate matter emissions, especially for the accumulation mode particles. Moreover, the performance in reducing nucleation mode particles is markedly better than that of accumulation mode ones, and this effect is greatly influenced by the engine operating conditions. At the beginning of DPF regeneration, the PN concentration increases sharply, especially the nucleation mode particles. After regeneration, the PN emissions decrease by two orders of magnitude. During regeneration, the particle size distribution exhibits a unimodal distribution, with the peak value increasing considerably and shifting toward smaller particle sizes. After regeneration, the particle size of the PN peak value slightly decreases and markedly shifts toward larger sizes, the accumulation mode particle concentration increases by 7.2 times, and the nucleation mode particle concentration increases by 2.6 times. Before the DPF regeneration, the axial temperature gradually decreases along the direction of the airflow, and the radial temperature gradually decreases from the center to the edge. During regeneration, the highest temperature occurs in the center of the DPF cross-section, whereas the temperature peak at the outlet interface occurs at the middle position of the DPF. The findings of this paper can provide scientific references to formulation and optimization of DPF regeneration strategies.