bluuebunny/crossref_metadata_2025_split huggingface dataset:
Performance Evaluation of Hydrogen-Powered Internal Combustion Engine City Bus for the Urban Mobility of Bologna, Italy
Authors: Brancaleoni Pier Paolo , Corti Enrico , Ravaglioli Vittorio , Moro Davide , Silvagni Giacomo , Brusa Alessandro , Cavina Nicolò , Ponti Fabrizio 
Published: December 2024

Abstract
Due to its geographical features, northern Italy is particularly prone to poor urban air quality and air pollution. Vehicular emissions are one of the main sources of pollutants and greenhouse gases emissions. Reducing the number of vehicles and promoting collective urban sustainable mobility represent the best solution to cut-down emissions from the transport sector in urban contexts. Among the possible solutions, hydrogen-fuelled internal combustion engines are particularly attractive, due to the interesting compromise between low manufacturing cost and low emissions (CO2 is absent, while other pollutants can be easily kept under control). Despite the lack of a distribution network, the operational path of hydrogen urban buses is known a priori, allowing them to operate without relying extensively on distribution infrastructure. This study presents a performance evaluation of a hydrogen-powered internal combustion engine bus within the metropolitan area of Bologna, Italy, assessed on two distinct routes representing diverse typical operating conditions. Through a dedicated virtual vehicle model, the performance of the bus is assessed in terms of fuel efficiency and NOx emissions. Additionally, a sensitivity analysis is conducted to evaluate the impact of variations in both the bus weight and passenger load on its performance metrics. The findings of the present study provide valuable insights into the sustainability of hydrogen buses for urban contexts, paving the way for their adoption as a sustainable transport solution.
Accuracy estimation of a CFD multiphysics approach to study a mixed parallel and serpentine flow channels PEM fuel cell
Authors: D’Alessio Emanuele , van Ginkel Rob M. , Donato Filippo , Agati Giuliano , Borello Domenico 
Published: December 2024

Abstract
This study presents a comprehensive analysis of a 50 cm2 fuel cell with mixed parallel and serpentine flow channels using Computational Fluid Dynamics modelling. Through rigorous validation against experimental measurements, the numerical model ensures accuracy in capturing convective and diffusive fluid flows, thermodynamic, and electrochemical phenomena and their mutual interaction. The study discusses a systematic procedure for achieving model convergence and identifies key parameters influencing the fitting of numerical polarization curves with experimental data. Operating within a temperature of 333 K, at atmospheric pressure, with a relative humidity of 100% for both the anode and cathode, the model offers crucial insights for advancing our understanding of fuel cell operation and guiding the development of more efficient and reliable technologies. In the activation region, reference exchange current densities and charge transfer coefficients were proved to play a significant role in reproducing the PEM fuel cell behaviour. Increasing the exchange current densities raises the voltage output in the activation polarization region while charge transfer coefficients affect the slope of the curve. In the ohmic region, a proton conduction coefficient of 1.84 and a contact resistance between gas diffusion layers and bipolar plates equal to 4.03e-7 Ω·m2 were used to fit the experimental polarization curve. After the tuning process, the numerical curve closely matches the experimental one with a maximum relative error of 2.40% and an R2 value of 0.9848. Moreover, a detailed analysis of the internal distribution of key variables was conducted for a specific point on the polarization curve (0.25 A/cm2). This analysis provided significant insights into the complex interplay of fluid dynamics, heat transfer, and electrochemical processes. Specifically, it was observed how the flow distribution, pressure drop, and reactant concentrations within the fuel cell channels and gas diffusion layers affect overall performance, highlighting the crucial role of convection and diffusion in reactant transport and the importance of managing heat for optimal cell operation.
Unsteady phenomena in the exhaust circuit of turbocharged automotive engines
Authors: Onnis Federico , Usai Vittorio , Marelli Silvia 
Published: December 2024

Abstract
The application of turbocharging is still a crucial aspect, especially in hydrogen engines where ultra-lean combustion is required, to mitigate abnormal combustion and NOx formation. The adoption of advanced turbocharging systems results in an increased complexity of the engine intake and exhaust circuits and requires a proper design to optimize unsteady flow phenomena.
Therefore, it is essential to understand the performance of the single elements of the turbocharging circuit and their interactions when coupled.
A specific test rig for components of propulsion system is operating at the University of Genoa, where investigations under steady, transient and pulsating flow conditions can be performed. This study presents the results of experimental investigations conducted under unsteady flow conditions on the exhaust manifold of an internal combustion engine, specifically examining unsteady phenomena in the turbine inlet circuit.
The pulsating flow is generated by a motor-driven cylinder head. Pressure signals recorded in different sections of the exhaust circuit located in the inlet and outlet turbine circuit are analysed in detail, quantifying also the effects of flow unsteadiness using parameters proposed in the open literature. In particular in the following article, the degree of instability, the Strouhal number and the reduced frequency are considered to quantify the impact of unsteady phenomena within the system for the considered lengths.
Understanding the unsteadiness within engine circuits is crucial for determining the appropriate modeling approach for system simulation. This work highlights that a quasi-steady flow model is appropriate for modeling individual branches for the exhaust manifold, while a wave action model is necessary for the entire exhaust circuit.
Virtual development of a multi-cylinder hydrogen spark ignition engine operating at lean burn conditions
Authors: Ugliano Emanuele , Bozza Fabio , Teodosio Luigi 
Published: December 2024

Abstract
Propulsion systems for automotive applications are facing the issues related to the stringent noxious emission and CO2 regulations which are driving the manufacturer and the researchers to the development of innovative powertrains. Among the different solutions, relevant efforts are being directed towards the decarbonisation of internal combustion engines (ICEs). In this scenario, the hydrogen, particularly the green one obtained through the water electrolysis using renewable energy sources, is emerging as a promising fuel for a future sustainable mobility. In this work, a multi-cylinder hydrogen Spark Ignition (SI) engine conceived for automotive applications is developed and optimized to operate under ultra/lean air/hydrogen mixtures. In particular, a 3-cylinder turbocharged hydrogen SI engine is virtually developed through a 0D/1D model, starting from a naturally aspirated single-cylinder SI unit; the latter is properly validated with experiments and 3D CFD outcomes in a previous authors’ activity. A fractal model is used for combustion modelling, coupled to a user-defined turbulence sub-model. The thermo-diffusive instability sub-model, based on Howarth theory, is integrated into the combustion model to correctly simulate the hydrogen engine operation at ultra/lean mixtures. In addition, the knock onset is evaluated with a Tabulated Kinetic of Ignition (TKI) approach, requiring a pre-computation of the auto-ignition delay times at varying the thermodynamic conditions. The main aim of the work is to forecast the hydrogen engine operation under full load and ultra-lean conditions, analysing performance, efficiency and NOx emissions at the knock limit. Subsequently, an optimization of the engine operation is carried out exploring different compression ratios, air/fuel proportions (lambda values) and water-to-fuel ratios. The objective of the initial optimisation is to optimise efficiency while respecting the safety constraint on the occurrence of shocks. Comparison with the base case, in which the maximum value is 35.6%, reveals an increase of 1.98% with CR equal to 13. However, in the case of the high-speed analysis, there is a decrease compared to the base case. The second analysis shows that the maximum lambda value that meets the imposed BMEP target is 2.1, thus minimising the NOx emissions of a multi-cylinder hydrogen engine under all conditions. A final analysis was conducted to study the impact of water injection on NOx for fixed rpm.
Alternative Propulsion Systems and Low/Zero Carbon Fuels for Different Marine Vessels
Authors: Perna A. , Cappiello A. , Di Cicco G. , Lanni D. , Rinauro B. , Romano F. , Minutillo M. 
Published: December 2024

Abstract
In 2022, shipping was responsible for around 706 million tonnes of carbon dioxide emissions, up 5% from 2020 and back to 2017-2018 levels. To accelerate the energy transition and reduce emissions in this sector, the International Maritime Organization (IMO) has set ambitious goals requiring all stakeholders’ radical actions. Several solutions have been proposed such as cruise speed reduction, on-board installation of a Carbon Capture and Storage system, use of low/zero carbon fuels in conventional internal combustion engines, and introduction or replacement of the main and auxiliary engines with novel technologies. Thanks to their high energy conversion efficiency, and reduced environmental impact, the interest in fuel cell-based systems for shipping propulsion has been rising in the last few years. In this work, the replacement of fossil fuel-based marine engines with fuel cell technology is analysed from technical and environmental points of view. A preliminary technical assessment, aiming at defining different powertrain configurations, is performed by starting from the characterization of the selected ships, in terms of installed power, navigation routes, and load profiles. The feasibility of the proposed solutions is evaluated by considering the fuel consumption and the emissions avoided with respect to the conventional solutions.
An Overview about FPT Industrial Telematic Service for Monitoring and Diagnostic purposes. First approaches to Signal Logger Data from Heavy-Duty Commercial Vehicles
Authors: D’Agostino Valerio , Verdone Gianmarco , Cardone Massimo 
Published: December 2024

Abstract
One of several services of FPT Industrial Customer Service team is Monitoring&Diagnostic of engines through telematic. FPT Industrial S.p.A. is an Italian brand of Iveco Group dedicated to the design, production, and sale of powertrains and solutions for on- and off-road applications. The focus of this study is on heavy-duty on-road vehicles. They are part of an Iveco vehicle fleet powered by FPT engines equipped with telematic devices. The telematic data have been used for energy efficiency and driving style relations and analysis; after every key-on event the acquisition and transmission of data start. An on-board device, called Telematics Mobile Diagnostic (TMD), is responsible for sending this data flow from Dongle, connected to the OBD port, to control room with a frequency of 1 Hz. The large amount of data will be useful for interesting analysis of drivers’ real use: an investigation about their behaviors and missions has been carried out. Therefore, the main purpose of the work is to keep track of vehicle efficiency, energy spent to distance travelled ratio (kWh/km). Hence, a correlation between the dynamicity of the drive, through Driving Scores and Pearson’s coefficient, and consumption has been proposed. The outcome is a characterization of the missions with few indexes, inferred by telematic data, without consulting any plot.
Mechanical design of a quartz oxy-combustion chamber: chemical-physical analysis of the combustion phenomenon
Authors: Brenda Raho , Marco Milanese , Arturo de Risi , Gianpiero Colangelo 
Published: December 2024

Abstract
Climate change and environmental degradation are huge threats to Europe and to the world. To overcome these problems, there are a series of government proposals with the aim of achieving carbon neutrality, or, at least, reducing net greenhouse gas emissions up to 55% by 2030. The greenhouse effect is caused by a high concentration of harmful emissions, especially CO2, in the atmosphere; hence, it is imperative to minimize their amount. Because of this, there is a strong effort to research suitable operational methods and secure useful technological advancements. A valid solution to actively contribute to the global objectives for achieving carbon neutrality is the oxy-combustion process, i.e., combustion in an oxygen atmosphere. This process can be considered as “clean” combustion because it does not produce pollutants such as NOx and SOx but only CO2 and steam. In addition, the production of essentially pure CO2 makes possible subsequent operations of carbon sequestration. The proposed paper describes the mechanical design and construction of a lab-scale oxy-fuel chamber, entirely made of quartz. The chosen material makes it possible to visualize, analyze and study the combustion process inside the chamber through imaging techniques by investigating its chemical and physical characteristics.
State of the art and working fluids for high temperature heat pumps
Authors: Di Salvatore F , Mauro A W , Pelella F , Viscito L 
Published: December 2024

Abstract
In the current framework of the European policy that pushes toward the ecological transition by promoting the use of low GWP refrigerants and the system electrification, high temperature heat pumps (HTHPs) can be considered as an important technology with huge applicative potential. Their capacity to boost the heat quality from lower to higher temperatures, in fact, makes these machines very interesting across numerous domains. On this regard, this paper presents a comprehensive critical review of the state of the art for applications and working fluids related to high temperature heat pumps. The focus is on the analysis of the heat pump thermodynamic cycles and performance, possible suitable refrigerants, operating source and sink temperatures, potential applications and related technical challenges. More than 25 scientific papers are reviewed, showing large application potential in the food, paper, metal and chemical industries, together with the residential sector.
Exploiting Deep Learning for the Optimization of Transonic Centrifugal Impellers
Authors: Pela Alessandro , Marconcini Michele , Arnone Andrea , Agnolucci Andrea , Toni Lorenzo , Valente Roberto , Belardini Elisabetta 
Published: December 2024

Abstract
Artificial intelligence is a powerful tool across numerous scientific disciplines. Within turbomachinery, the application of Artificial Neural Networks (ANNs) stands out for its capacity to facilitate the optimization of stage components. ANNs can reveal complex nonlinear relationships between geometric features, which can pose challenges even for experienced designers to discern. This paper explores impeller optimization, leveraging the capabilities of ANNs. Thanks to a parameterization scheme tailored for 3D geometries, neural network training utilizes a richly diverse database of geometric configurations. The investigation of the resulting Pareto front results in the discovery of highly efficient solutions across diverse geometrical configurations. Crucially, the utilization of ANNs yields multiple solutions with comparable performance, affording designers the flexibility to select solutions tailored to specific requirements, such as achieving a balance between maximum efficiency and operating range. Notably, the analysis of flow fields reveals how artificial intelligence uncovers diverse solutions to maximize efficiency. The paper introduces three optimized solutions for a high-Mach number impeller, each highlighting different blade geometries that impact flow fields and blade loadings within the transonic region. While sharing certain geometrical features, the three cases demonstrate notable variations in blade design. Performance is evaluated by analyzing the polytropic efficiency, work coefficient, and polytropic head coefficient curves, which allow a comparative evaluation of the maximum efficiency and operating range of the three impeller models.
Aerodynamic reverse engineering design using fuzzy logic
Authors: Dambrosio Lorenzo , Domenico Naschetti , Pascazio Giuseppe 
Published: December 2024

Abstract
The goal of this paper is to create a solid and efficient design method leveraging a fuzzy logic algorithm. This fuzzy logic system presents a non-analytical structure, facilitating the management of numerical mappings and data obtained by measurements and analytical relations, while also utilising the knowledge distributed in previous projects. Employing this information, the fuzzy logic algorithm can quickly generate an initial design, serving as a solid foundation for further optimisation. This first-glance solution can be leveraged to generate a few other designs in its neighbourhood that will then constitute the Fuzzy Logic Base of rules for further optimisation. The proposed method’s effectiveness and efficiency are demonstrated through the design of a nozzle for both subsonic and transonic flow conditions.
Weld seam positioning method for structural reinforcement based on 3D point cloud
Authors: Li Xiaohui , Qin Gaoe 
Published: December 2024

Abstract
Machine vision technology assists welding robot weld positioning, which can significantly improve welding accuracy and efficiency. This paper delves into a 3D point cloud-based positioning technique specifically tailored for structural reinforcement welds, utilizing the high-precision 3D structured light camera to get 3D point cloud data from the surface of the reinforcement structures, subsequently conducting a comprehensive analysis of the weld’s geometric characteristics. When the weld seam position can be directly collected, the side plate plane and the bottom plate plane of the reinforcement can be divided by the random sample consensus method. The weld points with rich curvature characteristics can be quickly and reliably selected according to the plane constraint. When the weld position cannot be measured directly, the prediction of the weld position is realized by extracting the edge of the upper surface of the reinforcing rib in the depth map and combining the plane normal vector of the base plate and the point laser correction vector. The experimental results show that this method can accurately locate the weld seam with high accuracy in both working scenarios.
Design of meter module assembly line based on automation
Authors: Liu Yuluan , Lin Jingxiang , Wei Lilong 
Published: December 2024

Abstract
This paper designs an automated assembly and binding device for power meters and communication modules, aiming to optimize the metering asset management process. The device ensures assembly quality and reduces manual intervention through full visual guidance and precise servo control. The design includes two automated assembly line solutions, realizing 36-second and 20-second assembly beats, respectively, which significantly improves production efficiency. Advanced automation technologies, such as 3D visual recognition, automatic screw guns, labeling flyers, etc., are used in major processes to ensure high efficiency and accuracy of the assembly process. In addition, the material flow turn design is flexible with a caching function, which enhances the continuity of the production line. Through the combination of multifunctional robots and intelligent modules, efficient and disordered gripping and assembling are realized, ensuring product quality and work stability. The research in this paper provides a practical solution for the automated assembly of meter modules and promotes the intelligent development of the electric power industry.
Design of automobile gearbox measurement and control system based on ARM7
Authors: Zhang Li , Huang Jinlin , Cao Guanghua 
Published: December 2024

Abstract
Aiming at the large energy loss and shortcomings of low control efficiency of the current automobile gearbox test bench, the antomobile gearbox measurement and control system are designed through the mehtod of DC energy regeneration and AC power generation. The JZ-type sensor is selected which is magnetoelectric with phase difference. The energy feedback unit is designed by using the double bridge parallel converter circuit. The user interface is programmed by Visual C + + with ARM7 as the core. The experimental results show that the system can detect the torque and speed accurately and automatically. Then display it in real time according to the given control. The test bench runs smoothly and reliably and meets the design requirements.
An improved k-means cluster method based on partial correlation coefficient for line-transformer connectivity identification in distribution network
Authors: Fang Tao , Lou Xiyue , Diao Xinzhuang , Hu Feihu 
Published: December 2024

Abstract
The accurate identification of line-transformer connectivity of the distribution network is very important for load balancing and line loss management. The electric quantity data can be used to identify the relationship, but the recognition accuracy is limited. The essence of relation recognition is unsupervised classification, but as there is no direct center of mass and distance, the traditional mainstream clustering method cannot be applied. Therefore, this paper proposes an improved K-means clustering algorithm based on a partial correlation coefficient. Firstly, spectrum analysis is carried out for the collected power data of the distribution transformer and the 10 kV line, and the high-frequency component of the data is obtained by the high-pass filter. Then, the K-means clustering algorithm improved by the partial correlation coefficient is used to set the electric energy data of each line as the initial centroid. The correlation between the station area and the line is calculated by using the concept of the partial correlation coefficient, and the station area represented by the minimum line distance is assigned to the corresponding line. The results show that this method can improve the accuracy of linear relation identification based on electric quantity data.
Design of an axial field direct-drive tidal stream generator
Authors: Liu Wenzhou , Yang Jinghuan , Wang Pengyu , Pei Lixin , Yang Yilong , Zhang Xuejun , Zhang Baowen 
Published: December 2024

Abstract
Tidal stream energy generation is a technology that harnesses the kinetic energy of tidal or ocean currents to produce electricity. Unlike traditional thermal and wind power generation, tidal stream energy generation relies on the natural movement of seawater for energy conversion. Due to the periodic and predictable nature of tides and currents, tidal stream energy generation offers high stability and reliability. This paper introduces the design of a micro-scale tidal generator with the power of 300W. An appropriate electromagnetic configuration was chosen, and the initial materials and electromagnetic structure of the generator were determined. Three-dimensional simulations were performed using finite element analysis. The design parameters of the prototype are reasonable, and all performance indicators meet the design requirements, confirming the feasibility of this generator for tidal stream energy generation.