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Computational study of the effect of friction coefficients and particle shape on the repose angle and porosity of sinter piles

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Particuology 2025年第3期98卷 231-240页

作者： Meng Li Yaowei Yu Henrik Saxén Process and Systems Engineering Laboratory Faculty of Science and EngineeringÅbo Akademi University20500TurkuFinland State Key Laboratory of Advanced Special Steel Shanghai Key Laboratory of Advanced FerrometallurgySchool of Materials Science and EngineeringShanghai University200444ShanghaiChina

Shape has an undeniable impact on particle behaviour,and the shapes of naturally occurring granular matter are typically *** studies of irregularly shaped particles are challenging but necessary to gain a better understanding of the flow of particulate *** study focuses on the behaviour of irregular sinter particles and applies the discrete element method to examine the effects of static and rolling friction coefficients and particle shape on the angle of repose and porosity of sinter piles.A three-dimensional model of an irregular sinter particle reconstructed by close-range photogrammetry served as the template for generating multi-sphere particles with varying numbers of sub-spheres(1,3,7,22,and 135)and sphericity ranging from 1 to *** of particle piles were conducted for a range of values of the coefficients of static and rolling *** results indicate that the angle of repose increases with static friction and also increases with rolling friction coefficient when it is lower than the static *** angle of repose shows clear dependence on particle shape,particularly for lower rolling friction *** friction coefficients for particles of five different shapes were individually determined through bulk calibration,and irregularly shaped particles in DEM were found to require lower friction *** was marginally affected by the static and rolling friction coefficients for spherical particles,while non-spherical particles showed porosity increasing with the rolling friction *** relationship between particle sphericity and porosity was nonlinear:as sphericity decreases from 1.00 to 0.69,the porosity first decreases to a minimum and then *** findings confirmed that both friction and particle shape have a significant influence on the structure of sinter piles,with implications for material handling and processing in industrial applications.

关键词： Sinter Discrete element method Friction coefficients Particle shape Repose angle Porosity

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Modeling and Simulation of Sand Particle Trajectories and Erosion in a Transonic Fan Stage

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Journal of Turbomachinery 2025年第7期147卷 071012页

作者： Ghenaiet, Adel Laboratory of Energy Conversion Systems Faculty of Mechanical Engineering and Process Engineering University of Science and Technology Houari Boumediene BP32 El-Alia Bab Ezzouar Algiers16111 Algeria

In desert regions, there is a significant presence of dust and sand particles lifted by storms and drawn into aircraft engines, resulting in considerable erosion. This numerical study investigates the dynamics of sand particles affecting the front components of a high-bypass turbofan engine (HBTFE). The components under consideration include a Pitot intake, a spinner, a fan rotor, inlet guide vanes (IGVs), and outlet guide vanes (OGVs). This research focuses on the engine’s operating conditions during takeoff from a Saharan airfield. The flow field is solved separately, and the data are transferred to an in-house particle trajectory code based on the Lagrangian model. The finite element method (FEM) is used to track sand particles as they move through the mesh cells, facilitating an accurate assessment of impacts and conditions necessary for calculating erosion rates. The results obtained indicate that a significant number of sand particles frequently impact the rotor blade, from the hub to approximately 80% of its span, due to deflection by the Pitot intake lip and outer contour. The pressure side (PS) of the rotor blade experiences severe erosion, with the highest erosion rates occurring at the leading edge (LE) and toward the trailing edge (TE). At the exit of the rotor, a substantial amount of particles flows through the OGVs and erode the PS, while fewer particles from the lower sections of the fan blade pass via the IGVs to the engine’s core. These findings highlight erosion-prone regions that require special protective coatings. Copyright © 2024 by ASME.

关键词： Turbomachine blades

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Parameter estimation in solar power plant systems: a comparative study of recursive and iterative techniques

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Sustainable Energy Research 2024年第1期11卷 1-12页

作者： Sadeghi, Kiavash Hossein Shafikhah, Mahmood Marashian, Arash Roshandel, Emad Razminia, Abolhassan Department of Electrical Engineering Faculty of Intelligent Systems Engineering and Data Science Persian Gulf University Bushehr Iran Process Control Laboratory Faculty of Natural Sciences and Engineering Åbo Akademi University Turku Finland College of Science and Engineering Flinders University Adelaide Australia

The development of a dynamic model for a popular implemented solar power plant is a critical task for power engineers aiming to enhance the plant’s performance and reliability. In this study, we utilized the prediction error method (PEM), a robust algorithm for system identification, to capture the plant’s operational characteristics with precision. Additionally, we employed both recursive and hierarchical algorithms to identify the system parameters effectively. The results from each identification method are rigorously quantified and analyzed, allowing for a detailed comparison of their performance. This comprehensive evaluation not only highlights the strengths and weaknesses of each approach, but also provides valuable insights into their practical applications in the context of solar power systems. © The Author(s) 2024.

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Use of robotics to coordinate health and safety on the construction site 41

Use of robotics to coordinate health and safety on the const...

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41st International Symposium on Automation and Robotics in Construction, ISARC 2024

作者： Dornik, Fabian Bartels, Niels Faculty of Process Engineering Energy and Mechanical Systems University of Applied Sciences Köln Germany Faculty of Civil Engineering and Environmental Technology University of Applied Sciences Köln Germany

ISBN: (纸本)9780645832211

The construction industry has the highest number of accidents compared to other sectors of the economy. Minimising the risk of accidents requires compliance with safety standards and constant monitoring by responsible persons. The use of robots for high-risk work can increase safety and prevent accidents on construction sites. On the other hand, the use of robots can create new health risks. Especially the use of UAVs is therefore highly regulated, whereas this is not the case for legged robots. This paper identifies the challenges and opportunities for coordinating health and safety on construction sites with robots. It is based on a literature analysis that looks at the status of the general area of application of robots and health and safety coordination services. Based on the literature analysis, guided workshops were held with various stakeholders (site managers, health and safety coordinators, German employer's liability insurance association (BG Bau), clients and planners). To validate the results, a quantitative survey was conducted. The interviewees believe that robots can assist them with activities on the construction site or take over some of the activities independently. Challenges identified the interviewees were mainly related to purchase costs, acceptance by construction workers an unclear legal framework. The results show that robots should work autonomously. To create synergies, robots should not only coordinate health and safety, but also carry out target-performance comparisons with the building model, produce daily construction reports with photos and take measurements of the trades. © 2024 ISARC. All Rights Reserved.

关键词： Robots

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A Review of Evaluation Metrics Algorithmic Used in Scholarly Research Recommender System 4

A Review of Evaluation Metrics Algorithmic Used in Scholarly...

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4th International Multidisciplinary Information Technology and engineering Conference, IMITEC 2024

作者： Ovono, Gerald Zuva, Travos Otunniyi, Temidayo Faculty of Applied and Computer Sciences Department of Computer South Africa VaalUniversity of Technology Faculty of Engineering and Technology Department of Process Control and Computer Systems South Africa

ISBN: (纸本)9798350387988

The exponential growth of academic publications has made scholarly research recommender systems indispensable tools for researchers. These systems rely on diverse evaluation metrics to assess their effectiveness and relevance. This paper provides a comprehensive review and analysis of these metrics, categorizing them into accuracy, ranking, diversity, user-centric, coverage, temporal, and computational metrics. By employing a mixed-methods approach, combining systematic literature review and empirical analysis, we identify the prevalence and application of these metrics across various scholarly domains such as literature, conferences, and reviewers. Our findings highlight the widespread use of traditional metrics like precision, recall, and Fl-score, while emphasizing the growing importance of novel metrics such as unexpectedness and serendipity, especially in literature and conference recommendations. We also underscore the domain-specific nature of metric selection, with user-centric evaluations more prominent in literature recommendations, and ranking-focused metrics dominant in conference and reviewer recommendations. Furthermore, the study reveals a significant gap in the use of temporal and computational metrics, suggesting key areas for future research. This review offers valuable insights for researchers and practitioners, guiding them in metric selection and highlighting potential directions for enhancing the effectiveness, adaptability, and user satisfaction of scholarly recommender systems. © 2024 IEEE.

关键词： Algorithms Evaluation Metrics Novelty Recommender systems Scholarly Research Serendipity

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Heterogeneous numerical modelling for the auto thermal reforming of crude glycerol in a fixed bed reactor

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Chinese Journal of Chemical engineering 2022年第2期35卷 261-268页

作者： Jason Williams Hussameldin Ibrahim Nima Karimi Kelvin Tsun Wai Ng Clean Energy Technologies Research Institute Process Systems EngineeringFaculty of Engineering and Applied ScienceUniversity of ReginaRegina SK S4S 0A2Canada Environmental Systems Engineering Faculty of Engineering and Applied ScienceUniversity of ReginaRegina SK S4S 0A2Canada

A mathematical model for the catalytic autothermal reforming(ATR)reaction of synthetic crude glycerol to hydrogen in a fixed bed tubular reactor(FBTR)and over an in-house developed metal oxide catalyst is presented in this *** heterogeneous model equations account for a two-phase system of solid catalyst and bulk feed ***,the ATR of crude glycerol reaction scheme and intrinsic kinetic rate model over an active,selective,and stable nickel-based catalyst were integrated in the developed ***,the model was validated using experimental data generated in our labs for the ATR of synthetic crude *** modelling results adequately described the detailed gas product composition and distribution,temperature profiles,and conversion propagation in the axial direction of the fixed bed reactor over a wide range of reaction temperature(773–923 K)and mass-time(12.71–158.23 g cat·min·(mol C)^(-1)).The crude glycerol conversion predicted with the model showing a close resemblance to those obtained experimentally with an average absolute deviation(AAD)of less than 8%.The maximum crude glycerol conversion and hydrogen yield were found to be 92%and 3 mol hydrogen/mol crude glycerol,***,the gas product concentration profile in the reactor was adequately described(90%)accuracy with a hydrogen concentration of 39%(volume).

关键词： Hydrogen crude glycerol Autothermal reforming Numerical analysis Fixed-bed reactor

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CO_(2)emission evaluation and cost analysis of oxygen blast furnace process with sintering flue gas injection

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Journal of Iron and Steel Research International 2024年第9期31卷 2101-2109页

作者： Wei Zhang Jia-meng Lei Jing-qi Li Guo-jun Ma Henrik Saxén The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan430081HubeiChina Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education Wuhan University of Science and TechnologyWuhan430081HubeiChina Process and Systems Engineering Laboratory Faculty of Science and EngineeringÅbo Akademi UniversityÅbo20500Finland

In order to achieve ultra-low emissions of SO_(2)and NO_(x),the oxygen blast furnace with sintering flue gas injection is presented as a promising novel *** CO_(2)emission was examined,and a cost analysis of the process was *** results show that in the cases when the top gas is not circulated(Cases 1–3),and the volume of injected sintering flue gas per ton of hot metal is below about 1250 m^(3),the total CO_(2)emissions decrease first and then increase as the oxygen content of the blast *** the volume of injected sintering flue gas per ton of hot metal exceeds approximately 1250 m^(3),the total CO_(2)emissions gradually *** the recirculating top gas and the vacuum pressure swing adsorption are considered,the benefits of recovered gas can make the ironmaking cost close to or even lower than that of the ordinary blast ***,the implementation of this approach leads to a substantial reduction in total CO_(2)emissions,with reductions of 69.13%(Case 4),70.60%(Case 5),and 71.07%(Case 6),*** integrating previous research and current findings,the reasonable oxygen blast furnace with sintering flue gas injection can not only realize desulfurization and denitrification,but also achieve the goal of reducing CO_(2)emissions and ironmaking cost.

关键词： Oxygen blast furnace Sintering flue gas CO_(2)emission Ironmaking cost

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Stability and bifurcation analysis of delayed tri-trophic food chain model in poisoned environment with fear effect and additional food

Stability and bifurcation analysis of delayed tri-trophic fo...

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作者： Ramasamy, Sivasamy Banjerdpongchai, David Park, PooGyeon Center of Excellence in Intelligent Control Automation of Process Systems Department of Electrical Engineering Faculty of Engineering Chulalongkorn University Bangkok Thailand Department of Electrical Engineering Pohang University of Science and Technology Pohang Korea Republic of

One of the most important goals of theoretical ecologists is to find a strategy for controlling the chaos in ecological models to maintain healthy ecosystems. We investigate the influence of fear and the supply of additional food to predators in a delayed tri-trophic food chain model, where interference among the species is determined by Holling type-II functional response. The proposed model incorporates the fact that the growth rates of prey and middle predators are decreased due to the fear of middle and special predators, respectively. The additional food is supplied to both predators by either nature or external agencies. Furthermore, the poisoned prey in the predator's environment is taken into account. In the proposed model, we use two time delays: one for the growth term of the middle predator and another for the gestation delay of the special predator. We determine the conditions for the existence of ecologically feasible equilibrium points and their local and global stability. In addition, we establish the conditions for the existence of Hopf bifurcation around interior equilibrium to seek periodic behavior in nondelayed and delayed models. Numerical investigations are performed to justify the proposed theoretical findings through phase portraits, time series of solutions, and bifurcation diagrams. We observe that the chaotic dynamics of a tri-trophic food chain model can be controlled by the proper choice of the fear effect and by supplying additional food parameters. As a result, our findings provide more ecological insights into the dynamics of the delayed tri-trophic food chain model with the fear effect and additional food supply. © 2023 John Wiley & Sons, Ltd.

关键词： Hopf bifurcation

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Design of Supervisory Model Predictive Control for HVAC systems and Two Zones with Consideration of Energy Efficiency and Thermal Comfort 23

Design of Supervisory Model Predictive Control for HVAC Syst...

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23rd International Conference on Control, Automation and systems, ICCAS 2023

作者： Srisurapanon, Panithan Banjerdpongchai, David Chulalongkorn University Center of Excellence in Intelligent Control Automation for Process Systems Faculty of Engineering Department of Electrical Engineering Pathumwan Bangkok10330 Thailand

ISBN: (纸本)9788993215274

This paper presents the design of supervisory model predictive control for HVAC systems and two zones. The supervisory control (SC) is designed to find the optimal reference temperature of each zone. The design criteria consist of the total operating cost (TOC) and the thermal comfort cost (TCC). Then, the model predictive control (MPC) is designed to track the optimal reference signals. When SC and MPC are designed for two zones simultaneously, they are referred to centralized SC and centralized MPC. On the other hand, when SC and MPC are designed for two zones separately, they referred to decentralized SC and decentralized MPC. We then compare the results between the decentralized control and the centralized control. The trade-off curve shows that the performance of centralized control is better than that of decentralized control. In particular, centralized MPC improves the performance in tracking reference signals. Furthermore, TOC of centralized control is lower than that of decentralized control. It can be concluded that the centralized control is appropriate for two zones in terms of the tracking of reference and the electrical charge. © 2023 ICROS.

关键词： Model predictive control

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Universality class of machine learning for critical phenomena

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Science China(Physics,Mechanics & Astronomy) 2023年第12期66卷 63-70页

作者： Gaoke Hu Yu Sun Teng Liu Yongwen Zhang Maoxin Liu Jingfang Fan Wei Chen Xiaosong Chen School of Systems Science and Institute of Nonequilibrium Systems Beijing Normal UniversityBeijing 100875China Data Science Research Center Faculty of ScienceKunming University of Science and TechnologyKunming 650500China State Key Laboratory of Multiphase Complex Systems Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China

Herein,percolation phase transitions on a two-dimensional lattice were studied using machine learning *** reveal that different phase transitions belonging to the same universality class can be identified using the same neural networks(NNs),whereas phase transitions of different universality classes require different *** on this finding,we proposed the universality class of machine learning for critical ***,we investigated and discussed the NNs of different universality *** research contributes to machine learning by relating the NNs with the universality class.

关键词： universality class machine learning percolation

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