Engineering Development Research Articles

Conjugate heat transfer performance of a ceramic matrix composite plate considering the influences of the mesoscopic properties of yarns

Ceramic matrix composites (CMCs), as a type of material with low density and excellent temperature resistance, are highly conducive to the lightweight and efficient development of future aerospace engines. It is essential to investigate the anisotropic thermal properties of CMCs when applying them to high-temperature components of aerospace engines. This study examined three types of film holes formed in different components of CMCs and compared the overall cooling effectiveness. The influence of the blowing ratio on the overall cooling effectiveness of composite material plates was investigated. The results showed that Type I exhibited better overall cooling effectiveness distribution than Types II and III. With the increase in blowing ratio, the overall cooling effectiveness of the plate was improved. The overall cooling effectiveness at M = 2.0 was 19.67 %, 16.72 %, and 12.1 % higher than those at M = 0.5, 1.0, and 1.5, respectively. The study also investigated the influence of the principal thermal conductivity and volume fraction of yarn on overall cooling effectiveness. An increase in the principal thermal conductivity resulted in an initial deterioration followed by improvement in the cooling effect in the upstream region, while increasing the yarn volume fraction enhanced the cooling effect of the plate.

Payoff-driven migration promotes the evolution of trust in networked populations

Establishing and maintaining trustworthy behaviors in large populations of self-interested individuals is a significant problem which received extensive attentions from research fields such as evolutionary biology, economics, sociology and engineering. As a well-known model that captures social trust dilemmas, the N-player trust game is adopted to investigate the evolution of trust in groups consisting of investors and trustees. In addition, to model real scenarios in dynamic environments, we introduce a novel migration mechanism, called adaptive environment-benefit-driven migration, which considers the influence of individuals’ payoffs on migration. Through theoretical analysis and Monte Carlo simulations, we demonstrate the effectiveness of the migration mechanism on facilitating trust behaviors in the framework of evolutionary game theory. We find that the population density plays a crucial role in establishing trust. Simulation results reveal that trust can be fostered in a dynamic environment influenced by individual migration with the medium vacancy rate. This work significantly contributes to the understanding of mutual trust behaviors in networked social systems from a more realistic perspective.

Bioconvection flow of Carreau nanomaterial invoking Soret and Dufour impacts

Background and objectiveThermal transport enhancement through nanomaterial flow has gained much attention of the investigators recently. Such attention is for applications in engineering, petroleum industries, geothermal engineering and pharmaceutical developments such as X-ray imaging, welding process, semiconductor material production, thermal storage system, electric cooling devices, drug delivery, magma solidification etc. In view of such interest here we analyze the bioconvective stretched flow of Carreau nanoliquid. Thermal, microorganism and mass convective constraints are considered. Gyrotactic microorganisms within presence of chemical reaction is considered. Variable thermal conductivity is considered. Dufour and Soret features are under consideration. Thermophoresis diffusion and random movement features are considered. Energy relation comprises heat generation and radiation. MethodologyNonlinear dimensionless expressions are developed by employing suitable transformations. Numerical computations are obtained by implementation of Newton built in-shooting technique. ResultsPerformance of liquid flow, concentration, microorganism field, and thermal field is studied. Numerical values of quantities of engineering performance via influential parameters are explored. Larger Weissenberg number yield velocity increase. Reduction in velocity through bioconvection Rayleigh number is witnessed. Concentration and thermal field through solutal thermal Biot numbers have similar effect. An increment in thermal distribution and Nusselt number for Dufour number is detected. Increasing values of Soret number and chemical reaction correspond to decay in concentration. An augmentation in thermal transfer rate and temperature through radiation is noticed. An increment in density number against Peclet and bioconvection Lewis numbers is noticed.

Enhancing employee performance appraisal through optimized association rule algorithms: a data mining approach.

The planning and development department of the China Yangtze river three gorges engineering development corporation aims to improve its intelligent performance management system in accordance with the company's vision. This paper presents a study on enhancing intelligent performance management in the Planning and Development Department of the China Yangtze River Three Gorges Engineering Development Corporation. By combining data mining techniques with association rule algorithms, a performance prediction model was established. The goal is to explore a performance management system aligned with the company's vision and the specific characteristics of construction enterprises. Experimental results show the effectiveness of the GABPNN model, achieving a prediction error of 5% or less in seven out of seventeen sample points, with a maximum relative error of 20.86%. The suggested performance management system presents a useful strategy for construction companies to improve their performance evaluation procedures, boosting overall management efficiency and aligning with their distinctive traits.

Sustainable Development in Green Mining and Geotechnical Engineering—An Overview

The sustainable development of green mining and geotechnical engineering has become a crucial area of study in light of the increasing global efforts toward environmental conservation and responsible resource extraction [...]

Geometrically modified bovine pericardium membrane promotes the expression of molecules targeted for a faster integration and vascularization process

IntroductionIn recent years, advancements in technology and the refinement of engineering techniques have facilitated the development of tissue engineering, placing particular emphasis on the use of 3D-biomaterials with several structural and chemical geometric features. In particular, increasing information on biomaterial geometric surfaces has allowed for a better understanding of tissue regenerative processes. In the present study a comparison between BioRipar®, bovine pericardium membrane, modified with micrometric roundish regular open pores (BioR-Ps) and BioRipar® without pores (BioR-NPs) has been investigated.MethodsThe expression of adhesion molecules such as: fibronectin, vimentin, focal adhesion kinase (FAK), integrin 1β, integrin α5, E-cadherin, and molecules involved in neovascularization processes such as: vascular endothelial growth factor (VEGF) and vascular endothelial growth factor receptor (VEGF-R) were evaluated in an in vitro model containing primary culture of human periodontal ligament stem cells (hPDLSCs) through multiparametric analysis.ResultsThe results indicated a markedly significant expression of all the abovementioned molecules in hPDLSCs cultured withBioR-Ps compared to hPDLSCs cultured with BioR-NPs. Scanning electron microscopy analysis indicated a marked interaction between the cells and the substrate, particularly evident in the proximity of open pores in the hPDLSCs cultured on the BioR-P surface compared to hPDLSCs cultured on the BioR-NP surface. Thus, the presence of micrometric open pores on the scaffold stimulates the proliferation potential of cells apart from their adhesion ability on the patch, particularly near the poresDiscussionExpression of angiogenic molecules strengthened the performance of the modified BioR-Ps. During synthesis, 3D-biomaterial micrometric open-pores enable better bonding between cells and materials, increasing contact area and promoting cellular molecular signals in biomaterial-guided tissue engineering.

Generating Tooth Organoids Using Defined Bioorthogonally Cross-Linked Hydrogels.

Generating teeth in vitro requires mimicking tooth developmental processes. Biomaterials are essential to support 3D tooth organoid formation, but their properties must be finely tuned to achieve the required biomimicry for tooth development. For the first time, we used bioorthogonally cross-linked hydrogels as defined 3D matrixes for tooth developmental engineering, and we highlighted how their properties play a pivotal role in enabling 3D tooth organoid formation in vitro. We prepared hydrogels by mixing gelatin precursors modified either with tetrazine (Tz) or norbornene (Nb) moieties. We tuned the hydrogel properties (E = 2-7 kPa; G' = 500-1500 Pa) by varying the gelatin concentration (8% vs 12% w/V) and stoichiometric ratio (Tz:Nb = 1 vs 0.5). We encapsulated dental epithelial-mesenchymal cell pellets in a library of hydrogels and identified a hydrogel formulation that enabled successful growth kinetics and morphogenesis of tooth germs, introducing a defined tunable platform for tooth organoid engineering and modeling.

Methods and equipment for analysis and diagnosis of marine engines during navigation

ABSTRACT Expert diagnostic systems are required for the development of intelligent marine engines and other ship systems. Measurement and analysis of marine engine parameters are fundamental in ensuring the efficient operation of these key propulsion systems. This paper introduces a novel measurement device and method capable of real-time monitoring of cylinder pressure and emissions in marine engines. The experimental procedure involved measuring critical engine parameters and emissions, such as NOx, CO2, and particulate matter, under various operating conditions. The device provided accurate real-time data acquisition, enabling detailed analysis of combustion processes and emission profiles under various operating conditions. Furthermore, a numerical model was developed, like digital twins, which utilized the measured data to simulate engine performance, predict potential failures, and optimize operational parameters to enhance efficiency and reduce environmental impact. The two most important parameters: the indicated cylinder pressure and NOx emissions were simulated and validated. Measured NOx was measured 889 ppm at 90% and simulated results was 985 ppm, which is 10% difference. Specific fuel consumption has less than 1% difference between measured and simulated data. Novelty of this work is the methodology used in the testing and calibration processes. Current actual parameters of engine operation are monitored, based on which a comparative analysis is made in real time. Previous diagnostic control systems did not provide diagnostics, comparative analysis and optimization in real time. The integration with digital twin allowed potential wear and tear predictions, fuel consumption optimization, and emission reduction strategies, showcasing the potential of this technology to improve marine engine diagnostics and maintenance. The device and its virtual counterpart worked well together to provide a complete understanding of the engine’s response. This facilitates proactive maintenance strategies and contributes to eco-efficiency in the maritime sector.

Analysis and Comparison of the Performances and Applications for the State-of-art Thermal Engines

Abstract. As a matter of fact, the development of contemporary internal combustion engines focuses on enhancing fuel efficiency and reducing emissions due to stringent environmental regulations. With the rise of electric cars, the development of hybrid technologies has driven innovation in internal combustion engines, and many modern vehicles combine internal combustion engines with electric motors. In this study, it introduces three different types of thermal engines with latest application in different transportation. By analyzing the limitations of internal combustion engines like thermodynamic limits and emission causing air pollution, it points the direction of future efforts on thermal engines. According to the results, internal combustion engines can be improved by increasing compression ratio through optimizing design and using better fuel like hydrogen. This article hopes to provide a clear understanding of the advantages and limitations of internal combustion engines. For companies and researchers, especially in the automotive sector, it aims to support strategic decisions in engine design and deployment.

Study on carbon emissions of a small hydropower plant in Southwest China

Hydropower plants with a small installed capacity, which are widely distributed in mountainous areas with abundant rainfall and steep rivers, play an important role in resolving energy problems in remote rural areas. These plants are a crucial source of clean electricity generated from water power. Harnessing local water resources not only helps alleviate energy shortages, but also reduces reliance on fossil fuels, contributing significantly to China’s national goals of achieving peak carbon emissions and carbon neutrality. This study investigates the carbon footprint of the Huangshadong Reservoir Project in Chongqing, China. The entire life cycle of the hydropower plant is assessed, including the preparation, construction, operation and maintenance, and demolition phases. The uncertainty was evaluated using the error propagation method. Following analysis, suggestions for carbon footprint reduction measures were proposed. Results showed that the total carbon footprint and the carbon intensity of the Huangshadong Reservoir Project over its entire life cycle are 33,148.29 t CO2e and 417.75 g CO2e/kWh, respectively. Of the total carbon footprint, the preparation phase, construction phase, operation and maintenance phase, and demolition phase account for 0.04%, 67.06%, 26.2%, and 6.7%, respectively. It means that the requirement for cement during the construction phase represents an important contribution to the entire life cycle carbon footprint of a small hydropower plant. As an integrated water conservancy project, the carbon intensity of the Huangshadong Reservoir Project is higher than that of medium-sized and large hydropower plants. However, its carbon intensity is lower than the emission factor of fossil power plants. The research results provide reference for both planning and construction of small hydropower plants and low-carbon development of rural hydraulic engineering.

Development of a recommendation engine for university study programme selection: A regression-based approach

This paper is the third in a series focused on bridging the gap between secondary and higher education. Our primary objective is to develop a robust theoretical framework for an innovative e-business model called the Undergraduate Study Programme Search System (USPSS). This system considers multiple criteria to reduce the likelihood of exam failure or the need for multiple retakes, while maximizing the chances of successful program completion. Testing of the proposed algorithm demonstrated that the Stochastic Gradient Boosted Regression Trees method outperforms the current method used in Lithuania for admitting applicants to 47 educational programs. Specifically, it is more accurate than the Probabilistic Neural Network for 25 programs, the Ensemble of Regression Trees for 24 programs, the Single Regression Tree for 18 programs, the Random Forest Regression for 16 programs, the Bayesian Additive Regression Trees for 13 programs, and the Regression by Discretization for 10 programs.

Modeling of Hydrogen Combustion from a 0D/1D Analysis to Complete 3D-CFD Engine Simulations

Hydrogen and its unique properties pose major challenges to the development of innovative combustion engines, while it represents a viable alternative when it is based on renewable energy sources. The present paper deals with the holistic approach of hydrogen combustion modeling from a 0D/1D reactor evaluation with Cantera up to complete engine simulations in the 3D-CFD tool QuickSim. The obtained results are referenced to the current literature and calibrated with experimental data. In particular, the engine simulations are validated against measurements of a single-cylinder research engine, which was specifically adapted for lean hydrogen operation and equipped with port fuel injection and a passive pre-chamber system. Special attention is hereby given to the influence of different engine loads and varying lambda operation. The focus of this work is the complementary numerical investigation of the hydrogen flame speed and its self-ignition resistance under the consideration of various reaction mechanisms. A detailed transfer from laminar propagation under laboratory conditions to turbulent flame development within the single-cylinder engine is hereby carried out. It is found that the relatively simple reaction kinetics of hydrogen can lead to acceptable results for all mechanisms, but there are particular effects with regard to the engine behavior. The laminar flame speed and induction time vary greatly with the inner cylinder conditions and significantly affect the entire engine’s operation. The 3D-CFD environment offers the opportunity to analyze the interactions between mixture formation and combustion progress, which are indispensable to evaluate advanced operating strategies and optimize the performance and efficiency, as well as the reliability, of the engine.

Exergy analysis of a diesel methanol dual fuel engine with different regulatory strategies for meeting China VI emission regulations

To reveal the mechanism for high brake thermal efficiency (BTE) of diesel methanol dual fuel (DMDF) engine meeting China VI emission regulations without urea, experimental and computational methods were used to study the exergy distribution with different regulatory strategies. As the methanol energy ratio (MER) increased, the incomplete combustion exergy loss increased from 0.3 % to 5.5 %, while the exhaust exergy loss and heat transfer exergy loss decreased slightly. As the HP-EGR increased from 3 % to 23 %, exergy losses of incomplete combustion and exhaust decreased, resulting in a reduction in the engine exergy losses. As the LP-EGR increased from 3 % to 21 %, the exergy losses of heat transfer and incomplete combustion slightly decreased. By advancing the main injection timing, the decrease in exhaust flow rate and temperature led to a decrease in exhaust exergy loss and the combustion efficiency was improved from 95.0 % to 96.5 %. Both of them resulted in the highest exergy efficiency of 35.2 % at 12°CA BTDC. Finally, the exergy distributions of DMDF and diesel modes were compared at high and low loads. The research results can provide theoretical basis and engineering practical value for the development and optimization of DMDF engines from the perspective of exergy.

Hypergravity as a Possible Way of Bone Tissue Engineering in Osteoblastic Differentiation from Mesenchymal Stem Cells: A Systematic Review

Background: Tissue engineering development has become a highlight in recent decades. One of the key areas of focus is producing mature bone tissue to overcome orthopedic problems, such as bone defects. Various cultures have been implemented on stem cells; some induce osteoblastic differentiation markers, while others have the opposite effect. Microgravity has been proven in several studies to inhibit the expression of osteogenic differentiation markers. Conversely, hypergravity is expected to have the opposite impact, supporting stem cells in the osteogenesis pathway. Methods: A literature search was conducted using online databases including Sciencedirect, PubMed, and Proquest, covering the period from 2008 to 2022. This search considered only experimental studies published in English. The keywords used in this research were "hypergravity" and "mesenchymal stem cell." All acquired data were processed and analyzed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines (2020). Results: Initially, 190 studies were collected from online databases based on relevant keywords. After screening, 5 studies were included in the final analysis, focusing on hypergravity treatment and its effects on mesenchymal stem cells (MSCs). Conclusion: Hypergravity shows a significant and strong impact on osteoblastic differentiation. This study revealed that a gravity force of 30G and a culture duration of 7 to 14 days are the most optimal combination for inducing osteoblastic differentiation in MSCs.

Exploring the Role of Action Research in Enhancing Quality Management in Teacher Education: A Case Study

The sincere pursuit process called educational research has developed in modern times. Thus, academic research is a systematic activity devoted to discovering and developing well-organized knowledge that always seeks to find or solve a problem. At present, due to the increasing modernization and engineering development in the education system, research has become inevitable in solving operational problems, as well as in the teacher education field, various problems related to teaching and training and action by inventing various developmental approaches in the field of quality management Research. According to Palmer and Johnson (1971), action research is a method of using research for social activities that involve groups of people to solve problems and find root causes, as if the research itself is a part of empowerment and action. This article will explore the inter-dependence of action research and quality management in teacher education.

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.

Multiphysics Simulation and Concept of an Electromagnetically Control Volumetric Pixel as a Step Towards a Shape Morphing Composite

Abstract Constant development of robotics forces scientists and engineers to work on robots that are more visually and rigidly compatible with the environment around us. To make this possible, new flexible structures are necessary that enable programmatic shape change. To meet this need, in this work we present the concept and modelling methodology of a new structure enabling shape change using electromagnetic forces produced in liquid metal conductor and its stiffening using a granular jamming mechanism. This work presents the structure concept, the description of modelling methodology and empirical validation including the magnetitic field, scanned by magnetic field camera, and displacement distribution.

Investigation of Computational Thinking Skills through Instructional Techniques, Games and Programming Tools

Computational thinking (CT) has become a vital approach to problem-solving. This method has been proven successful in various areas, especially science, technology, engineering, mathematics (STEM), and professional development. The integration of CT in education provides a practical approach to solving problems. This concept paper investigated the various uses of instructional techniques and programming tools to enhance CT skills used in previous empirical research. CT consists of four main pillars: decomposition, which refers to breaking down identified problems into smaller parts; pattern recognition, which involves finding occurring patterns that can be seen; abstraction through identification of important details and removing unnecessary information; and algorithm, where a step-by-step procedure is solution is made. By exploring instructional strategies and programming environments, this paper outlines the possible impacts of these instructional strategies, games, and programming environments on improvement in CT skills, thus providing a theoretical basis for future empirical studies. The strength and combination of these approaches provide a comprehensive learning experience. This paper also suggests instructional techniques and programming tools to enhance underexplored CT skills based on research gaps.

Breakup dynamics in a pressure-swirl injector for urea-water solution applications: A computational study

The co-optimization of in-cylinder combustion and after-treatment technology has become a major aspect in engine design and development, with the goal of meeting the increasingly restrictive emission regulations in the transportation industry. Selective Catalytic Reduction is a robust technology to control the emission of NOx, and the injection of urea in water solution is the exhaust tailpipe is a key aspect of its operation. The proposed work uses high-fidelity Computational Fluid Dynamics to characterize the atomization dynamics of the liquid jet in relevant cross-flow conditions. The study focuses on a commercial low-pressure (9 bar) pressure-swirl injector which is characterized in its internal geometry through high-resolution X-ray micro-computational tomography. The internal two-phase flow has been modeled according to the volume-of-fluid approach in a large eddy simulation framework and validated against near-nozzle X-ray radiography measurement. Moreover, characterizing the breakup dynamics for the swirling hollow cone formation, and assessing the influence of the cross-flow in the breakup dynamics was completed. The results have been reported proposing Re-Oh maps and probability density functions of the spray kinematics. Higher cross-flow momentum generates an increase in the jet intact length and a reduction of the liquid droplet diameters. The axial momentum of the jet is affected by the cross-flow already in the near-nozzle region, determining a relevant deviation of the spray velocities. This work aims to inform the initialization of Eulerian-Lagrangian spray models through the assignment of droplet kinematics and static one-way coupling between volume-of-fluid results and Lagrangian spray parcels, to be used for system-size domain simulations.

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.