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Open AccessEditorial

Preface of the 17th International Scientific Conference on Aeronautics, Automotive, and Railway Engineering and Technologies (BulTrans-2025)

by Krasin Georgiev and Svetla Stoilova

Eng. Proc. 2026, 121(1), 16; https://doi.org/10.3390/engproc2025121016 - 14 Jan 2026

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Abstract

The BulTrans International Scientific Conference on Aeronautics, Automotive, and Railway Engineering and Technologies is organized by the Faculty of Transport, Technical University of Sofia [...] Full article

(This article belongs to the Proceedings of The 17th International Scientific Conference on Aerospace, Automotive, and Railway Engineering)

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2 pages, 141 KB

Open AccessEditorial

Statement of Peer Review

by Krasin Georgiev and Svetla Stoilova

Eng. Proc. 2026, 121(1), 33; https://doi.org/10.3390/engproc2025121033 - 10 Feb 2026

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Abstract

In submitting conference proceedings to Engineering Proceedings, the volume editors of the proceedings would like to certify to the publisher that all papers published in this volume have been subjected to peer review by the designated expert referees and were administered by [...] Read more.

In submitting conference proceedings to Engineering Proceedings, the volume editors of the proceedings would like to certify to the publisher that all papers published in this volume have been subjected to peer review by the designated expert referees and were administered by the volume editors following the policies announced on the conference website [...] Full article

(This article belongs to the Proceedings of The 17th International Scientific Conference on Aerospace, Automotive, and Railway Engineering)

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15 pages, 2262 KB

Open AccessProceeding Paper

Longitudinal Dynamic Characteristics of a Helicopter Rotor Blade: A Time-Based Modelling Method

by Gabriel Georgiev

Eng. Proc. 2026, 121(1), 1; https://doi.org/10.3390/engproc2025121001 - 8 Jan 2026

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Abstract

This article represents a numerical approach for estimating the helicopter rotor’s blade longitudinal dynamic characteristics considering several operational parameters. A characterization regarding the blade’s longitudinal, flapping, and vertical responses is derived by solving a system of differential equations that fully describe the rotor’s [...] Read more.

This article represents a numerical approach for estimating the helicopter rotor’s blade longitudinal dynamic characteristics considering several operational parameters. A characterization regarding the blade’s longitudinal, flapping, and vertical responses is derived by solving a system of differential equations that fully describe the rotor’s longitudinal dynamics. Dependencies between the lagging (longitudinal) velocity, the flapping velocity, and the vertical velocity over time are illustrated, taking into consideration the varying flapping frequency in a hovering regime. Additionally, the blade’s longitudinal parameters were evaluated in ground effect conditions when hovering at

\frac{H}{R} = 1

and

\frac{H}{R} = 0.5

. The studied time domain variables represent the rotor’s natural reaction capabilities when a disbalancing condition occurs. Eventually, an increase in the blade’s flapping frequency leads to a rise in the required period for reaching a stable condition with regard to the longitudinal and vertical responses. The ground effect zone reduces the blade’s lagging and flapping reactions as well. Full article

(This article belongs to the Proceedings of The 17th International Scientific Conference on Aerospace, Automotive, and Railway Engineering)

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13 pages, 4355 KB

Open AccessProceeding Paper

Study of Strength of Open Wagon with Tank Containers Under Operational Modes

by Alyona Lovska, Juraj Gerlici, Ján Dižo and Pavlo Rukavishnikov

Eng. Proc. 2026, 121(1), 2; https://doi.org/10.3390/engproc2025121002 - 8 Jan 2026

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Abstract

A removable module design is proposed to enable the use of open wagons for container transport. It acts as an intermediate adapter between an open wagon body and a tank container, ensuring the possibility of their reliable interaction. The dynamic loading of its [...] Read more.

A removable module design is proposed to enable the use of open wagons for container transport. It acts as an intermediate adapter between an open wagon body and a tank container, ensuring the possibility of their reliable interaction. The dynamic loading of its structure was determined to substantiate the proposed scheme of tank container transport on an open wagon. A mathematical model characterizing the longitudinal load of a tank container placed on an open wagon was developed for this purpose. The determined accelerations acting on the tank container were considered when studying its strength. It was established that, considering the proposed fastening scheme, the maximum stresses occurring in the tank container structure are lower by 21.8% than the permissible ones. Therefore, the strength of the tank container is ensured. Accelerations acting on an open wagon body and a tank container were determined and considered when studying their strength. It was found that the maximum stresses occurring in the open wagon body and the tank container, considering the proposed fastening scheme, are lower than the permissible ones. Therefore, the strength of their structures is ensured. The research conducted will contribute to increasing the efficiency of tank container transport by rail and, therefore, container transportation in general. Full article

(This article belongs to the Proceedings of The 17th International Scientific Conference on Aerospace, Automotive, and Railway Engineering)

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12 pages, 848 KB

Open AccessProceeding Paper

Forecasting the Number of Freight Trains by Categories Using Time Series Regression Analysis

by Svetoslav Martinov, Ivan Ivanov and Kiril Petkov

Eng. Proc. 2026, 121(1), 3; https://doi.org/10.3390/engproc2025121003 - 12 Jan 2026

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Abstract

A new hybrid forecasting model of the number of freight trains is proposed in this paper. This forecasting is performed by combining classification analysis and the use of Histogram-based Gradient Boosting Regressor (HGBR). The freight trains were classified into categories according to the [...] Read more.

A new hybrid forecasting model of the number of freight trains is proposed in this paper. This forecasting is performed by combining classification analysis and the use of Histogram-based Gradient Boosting Regressor (HGBR). The freight trains were classified into categories according to the transportation parameters and the train’s structure. A total of 100,441 freight trains with a constant number of wagons have been studied. The trains were ran over a 3-year basis period. The forecasting was performed using train categories for a forecast period lasting 1 year. The results obtained in this study have been validated by comparing them against real data from the trains that ran during the forecast period. The adequacy of the forecasting model was assessed using standard indicators, with the value of the Coefficient of Determination equal of 0.805. The results show the high level of accuracy of the model, despite discrepancies in the data of the base period concerning the train parameters for 34% of the trains. Full article

(This article belongs to the Proceedings of The 17th International Scientific Conference on Aerospace, Automotive, and Railway Engineering)

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13 pages, 2455 KB

Open AccessProceeding Paper

Study on the Energy Demand of Vehicle Propulsion to Minimize Hydrogen Consumption: A Case Study for an Ultra-Energy Efficient Fuel Cell EV in Predefined Driving Conditions

by Osman Osman, Plamen Punov and Rosen Rusanov

Eng. Proc. 2026, 121(1), 4; https://doi.org/10.3390/engproc2025121004 - 12 Jan 2026

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Abstract

Nowadays, the automotive industry is primarily driven by the CO₂ policy that targets net zero carbon emissions by 2035 from passenger cars and commercial vehicles. The main path to achieve this goal is the implementation of electric powertrains with the energy stored [...] Read more.

Nowadays, the automotive industry is primarily driven by the CO₂ policy that targets net zero carbon emissions by 2035 from passenger cars and commercial vehicles. The main path to achieve this goal is the implementation of electric powertrains with the energy stored in batteries, as the case for battery electric vehicles (BEV). However, this technology still faces some difficulties in terms of energy density, overall weight, charging time, and vehicle autonomy. From the other point of view, fuel cell electric vehicles (FCEV) offer the same advantages as BEV in terms of CO₂ reduction, providing better autonomy and lower refueling time. The energy demand by the electric powertrain strongly depends on the vehicle driving conditions as it directly affects energy consumption. In that context, the article aims to study the electrical energy demand of an ultra-energy efficient vehicle intended for a Shell eco-marathon competition in order to minimize hydrogen consumption. The study was carried out over a single lap on the racing track in Nogaro, France while applying the race rules from the competition in 2023. It includes a numerical evaluation of the vehicle resistance forces in different driving strategies and experimental validation on the propulsion test bench. Full article

(This article belongs to the Proceedings of The 17th International Scientific Conference on Aerospace, Automotive, and Railway Engineering)

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9 pages, 1725 KB

Open AccessProceeding Paper

An Analysis of Nonlinear Differential Equations Describing the Dynamic Behavior of an Unbalanced Rotor

by Petko Sinapov

Eng. Proc. 2026, 121(1), 5; https://doi.org/10.3390/engproc2025121005 - 12 Jan 2026

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Abstract

The present paper investigates the dynamic behavior of an unbalanced rotor mounted in a balancing machine. Differential equations of motion are derived without linearization using Lagrange equations of the second kind to determine the nonlinear nature of the system. This study proposes a [...] Read more.

The present paper investigates the dynamic behavior of an unbalanced rotor mounted in a balancing machine. Differential equations of motion are derived without linearization using Lagrange equations of the second kind to determine the nonlinear nature of the system. This study proposes a method for using differential equations in balancing to determine important parameters, such as the coordinates of the center of mass and the products of inertia of the rotor. An analysis of the interactions between the periodicities of the individual terms in the differential equations is carried out in order to eliminate terms with difficult-to-determine moments of inertia. Full article

(This article belongs to the Proceedings of The 17th International Scientific Conference on Aerospace, Automotive, and Railway Engineering)

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17 pages, 1115 KB

Open AccessProceeding Paper

Optimization of Feeder Buses Route to Connect High-Speed Railway Stations with Urban Areas

by Seham Hemdan, Mostafa Ramadan, Abdulmajeed Alsultan and Ayman Othman

Eng. Proc. 2026, 121(1), 6; https://doi.org/10.3390/engproc2025121006 - 12 Jan 2026

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Abstract

Feeder buses play an important role in supporting the accessibility of high-speed railway stations which leads to the improved efficiency of the transportation system. This paper proposes a new optimization technique for the design of feeder bus routes to the stations. It uses [...] Read more.

Feeder buses play an important role in supporting the accessibility of high-speed railway stations which leads to the improved efficiency of the transportation system. This paper proposes a new optimization technique for the design of feeder bus routes to the stations. It uses dynamic programming with a pulse algorithm seeking to maximize the number of serviced people considering the distance between the urban areas and high-speed railway station. The proposed algorithm was tested in a hypothetical network to find the optimum solutions and the running time needed. Moreover, the algorithm was applied to a real network as a case study in Aswan city, Egypt. Our results demonstrated significant improvements in the route design accuracy and efficiency. By applying the proposed algorithm, the potential demand values increased from 19.8% to 37.9% with a reasonable decrease in the running time compared to the literature. This research contributes to the advancement of transportation planning strategies by providing valuable insights into the optimization of feeder bus systems. The proposed model contributes to the scientific re-search and practical implementation by promoting a coordinated development of high-speed railway stations and urban areas. This may enhance the Egyptian high-speed railway technology, yielding substantial economic and social benefits. Full article

(This article belongs to the Proceedings of The 17th International Scientific Conference on Aerospace, Automotive, and Railway Engineering)

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10 pages, 233 KB

Open AccessProceeding Paper

Artificial Intelligence in Satellite Network Defense: Architectures, Threats, and Security Protocols

by Rumen Doynov, Maksim Sharabov, Georgi Tsochev and Samiha Ayed

Eng. Proc. 2026, 121(1), 7; https://doi.org/10.3390/engproc2025121007 - 13 Jan 2026

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Abstract

This paper examines the application of Artificial Intelligence (AI) to protect satellite communication networks, focusing on the identification and prevention of cyber threats. With the rapid development of the commercial space sector, the importance of effective cyber defense has grown due to the [...] Read more.

This paper examines the application of Artificial Intelligence (AI) to protect satellite communication networks, focusing on the identification and prevention of cyber threats. With the rapid development of the commercial space sector, the importance of effective cyber defense has grown due to the increasing dependence of global infrastructure on satellite technologies. The study applies a structured comparative analysis of AI methods across three main satellite architectures: geostationary (GEO), low Earth orbit (LEO), and hybrid systems. The methodology is based on guiding research question and evaluates representative AI algorithms in the context of specific threat scenarios, including jamming, spoofing, DDoS attacks, and signal interception. Real-world cases such as the KA-SAT AcidRain attack and reported Starlink jamming in Ukraine, as well as experimental demonstrations of RL-based anti-jamming and GNN/DQN routing, are used to provide evidence of practical applicability. The results highlight both the potential and limitations of AI solutions, showing measurable improvements in detection accuracy, throughput, latency reduction, and resilience under interference. Architectural approaches for integrating AI into satellite security are presented, and their effectiveness, trade-offs, and deployment feasibility are discussed. Full article

(This article belongs to the Proceedings of The 17th International Scientific Conference on Aerospace, Automotive, and Railway Engineering)

13 pages, 4191 KB

Open AccessProceeding Paper

Study of the Feasibility of Upgrading the Universal Flat Wagon for Transporting Long Cargoes

by Juraj Gerlici, Alyona Lovska and Mykhailo Pavliuchenkov

Eng. Proc. 2026, 121(1), 8; https://doi.org/10.3390/engproc2025121008 - 12 Jan 2026

Viewed by 462

Abstract

This article describes the possibilities of using universal flat wagons to transport long cargoes and suggests measures for upgrading them, which involve the installation of superstructures on the load-bearing structures to keep the cargo from overturning. The study was conducted using the flat [...] Read more.

This article describes the possibilities of using universal flat wagons to transport long cargoes and suggests measures for upgrading them, which involve the installation of superstructures on the load-bearing structures to keep the cargo from overturning. The study was conducted using the flat wagon model 13-401. Several options for implementing such superstructures have been considered. The load-bearing structure of the flat wagon was modeled as a rod system. The most rational option for upgrading was evaluated by assessing the force factors acting in the structure under the influence of external loads. According to the chosen upgrade option, a spatial model of the bearing structure of the flat wagon was built, and its strength was calculated using the finite element method. The proposed option was found to be appropriate. The results of the research can be used to improve the efficiency of transportation of long cargoes by universal flat wagons. Full article

(This article belongs to the Proceedings of The 17th International Scientific Conference on Aerospace, Automotive, and Railway Engineering)

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11 pages, 2489 KB

Open AccessProceeding Paper

Design and Verification of Computation Model of Side Flap of Wagon Series Rens

by Vladislav Maznichki, Svetoslav Slavchev, Stefan Krastev and Stancho Ivanov

Eng. Proc. 2026, 121(1), 9; https://doi.org/10.3390/engproc2025121009 - 13 Jan 2026

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Abstract

Side flaps are critical structural components of flat freight wagons, directly affecting cargo safety during transportation and playing an essential role in loading and unloading operations. Over the years, their reliability has been well established, with standardized designs available in UIC technical datasheets. [...] Read more.

Side flaps are critical structural components of flat freight wagons, directly affecting cargo safety during transportation and playing an essential role in loading and unloading operations. Over the years, their reliability has been well established, with standardized designs available in UIC technical datasheets. Despite this standardization, the introduction of newly manufactured or redesigned components necessitates technological validation through Finite Element Method (FEM) simulations and/or physical testing. This requirement holds irrespective of whether the component in question adheres to existing standards or is a novel development. This study presents the creation and application of computational models for the structural sizing and strength assessment of side flaps for flat wagons. The models are verified through a series of physical tests conducted by a research team at the Technical University of Sofia. Full article

(This article belongs to the Proceedings of The 17th International Scientific Conference on Aerospace, Automotive, and Railway Engineering)

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9 pages, 1881 KB

Open AccessProceeding Paper

An Assessment of Diesel Engine Performance Using a Dual-Fuel Diesel—Ammonia Injection

by Lucian Miron, Vlad-Alexandru Ungureanu, Radu Ionescu and Radu Chiriac

Eng. Proc. 2026, 121(1), 10; https://doi.org/10.3390/engproc2025121010 - 13 Jan 2026

Viewed by 701

Abstract

In the context of promoting strategies to mitigate the global warming effect resulting from greenhouse gas emissions produced by human activities, ammonia stands out as an important player in the decarbonization of various sectors, including transportation, energy, and other industries. Ammonia is an [...] Read more.

In the context of promoting strategies to mitigate the global warming effect resulting from greenhouse gas emissions produced by human activities, ammonia stands out as an important player in the decarbonization of various sectors, including transportation, energy, and other industries. Ammonia is an effective carrier of hydrogen, having three times the volumetric energy density of hydrogen itself. In this study, the authors present findings obtained from a group of experiments and simulations conducted on a diesel engine operating at a constant speed and under different loads, using a dual-fuel method in which ammonia was injected into the intake manifold to partially replace the original diesel fuel. The results demonstrate that it is possible to reduce fuel consumption and CO₂ emissions. NO_x dropped by 40.8% and soot by 13.4% under heavy load, while under light load, they dropped by 50.5% and 23.3%, respectively. Full article

(This article belongs to the Proceedings of The 17th International Scientific Conference on Aerospace, Automotive, and Railway Engineering)

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12 pages, 2475 KB

Open AccessProceeding Paper

Effect of Temperature Variations on Brake Squeal Characteristics in Disc Brake Systems

by Akif Yavuz, Osman Taha Sen, Mustafa Enes Kırmacı and Tolga Gündoğdu

Eng. Proc. 2026, 121(1), 11; https://doi.org/10.3390/engproc2025121011 - 13 Jan 2026

Viewed by 427

Abstract

Brake squeal is an undesirable high-frequency noise caused by vibrations induced by friction in disc brake systems. The noise is strongly affected by temperature, as this influences the material properties of the friction pair and the dynamic behaviour of the brake components. This [...] Read more.

Brake squeal is an undesirable high-frequency noise caused by vibrations induced by friction in disc brake systems. The noise is strongly affected by temperature, as this influences the material properties of the friction pair and the dynamic behaviour of the brake components. This study investigates the effect of temperature changes on the squeal characteristics of a disc brake system under different operating conditions. Experiments are carried out using a laboratory-scale test setup comprising a rotating disc, pneumatically actuated callipers, and precise measurement equipment. A series of test combinations is performed by systematically varying three parameters: disc surface temperature (40, 55, 70, 85, 100 °C), brake pressure (4.0 bar), and disc rotational speed (50, 100, 150, 200 rpm). Acceleration data are acquired using an accelerometer mounted directly on the calliper, while sound pressure data are measured with a fixed-position microphone located 0.5 m from the disc surface. The collected data are analyzed in the time and frequency domain to identify squeal events and their dominant frequencies. The effect of temperature on brake squeal noise and vibration varies with operating conditions, showing different patterns at low and high disc speed at constant brake pressure. This highlights the importance of considering both thermal and mechanical factors together when addressing brake squeal. Full article

(This article belongs to the Proceedings of The 17th International Scientific Conference on Aerospace, Automotive, and Railway Engineering)

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13 pages, 3706 KB

Open AccessProceeding Paper

Virtual and Physical Prototyping in Mechanical Shock Test of an EV Battery Module

by Georgi Todorov, Konstantin Kamberov, Tsvetozar Ivanov and Konstantin Dimitrov

Eng. Proc. 2026, 121(1), 12; https://doi.org/10.3390/engproc2025121012 - 13 Jan 2026

Viewed by 500

Abstract

This study presents a methodology used in the design certification of a battery module for electric vehicle applications. The methodology combines virtual and physical techniques to assess the structure under mechanical shock testing, according to the standards’ requirements. Virtual prototyping is used to [...] Read more.

This study presents a methodology used in the design certification of a battery module for electric vehicle applications. The methodology combines virtual and physical techniques to assess the structure under mechanical shock testing, according to the standards’ requirements. Virtual prototyping is used to quantify parameters as stresses and deformations. Performed simulations using the virtual prototype are validated by testing the physical prototype, which allows for assessing various design parameters with a high level of confidence. The testing of a physical prototype is performed using specialized equipment—a mechanical shock test bench—which is developed and manufactured especially for this task. The presented methodology is demonstrated in an industrial use case, and the main contribution of this study is related to the way the combination of virtual and physical prototyping and testing is used. Full article

(This article belongs to the Proceedings of The 17th International Scientific Conference on Aerospace, Automotive, and Railway Engineering)

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13 pages, 4348 KB

Open AccessProceeding Paper

Investigation of the Influence of Distributor Valve Position on Longitudinal Train Dynamics During Braking

by Stefan Krastev, Svetoslav Slavchev, Vladislav Maznichki, Petko Sinapov and Magdalen Velev

Eng. Proc. 2026, 121(1), 13; https://doi.org/10.3390/engproc2025121013 - 13 Jan 2026

Viewed by 379

Abstract

The distributor valve is one of the most important components in the pneumatic braking system of trains. It performs the functions of filling and releasing the brake cylinder. The distributor valve most widely used on Bulgarian railways operates in two positions, respectively, in [...] Read more.

The distributor valve is one of the most important components in the pneumatic braking system of trains. It performs the functions of filling and releasing the brake cylinder. The distributor valve most widely used on Bulgarian railways operates in two positions, respectively, in “freight train” mode (G) and in “passenger train mode” (P). The difference between them is determined by the different times for filling and emptying the brake cylinder. These times affect the moment of engagement of the braking system of each wagon in the train composition. This has a significant impact on the longitudinal forces obtained in the couplers. This paper is dedicated to the analysis of the influence of the distributor valve position on the longitudinal forces. A simulation study of the longitudinal behavior of a train set was carried out in Simulink^®, which consists of a locomotive and 43 freight wagons attached to it, with 80 t gross mass of each wagon. The railway cars are linked by elastic elements with nonlinear characteristics. The results represent the distribution of longitudinal forces in time. They are used for the investigation of the longitudinal dynamics of the train, with the aim of improving the running-dynamic qualities of the train during braking. Full article

(This article belongs to the Proceedings of The 17th International Scientific Conference on Aerospace, Automotive, and Railway Engineering)

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11 pages, 2119 KB

Open AccessProceeding Paper

The Influence of Printing Parameters on the Impact Strength of FDM 3D-Printed Polylactic Acid

by Tsvetomir Gechev, Veselin Tsonev, Petar Ivanov, Ivan Kralov and Krasimir Nedelchev

Eng. Proc. 2026, 121(1), 14; https://doi.org/10.3390/engproc2025121014 - 13 Jan 2026

Viewed by 450

Abstract

The paper investigates experimentally the influence of infill density, infill pattern, layer height, wall number, printing orientation, and material color on the impact strength of 3D-printed PLA (polylactic acid) samples by using the Charpy test method. The used printing method is FDM (Fused [...] Read more.

The paper investigates experimentally the influence of infill density, infill pattern, layer height, wall number, printing orientation, and material color on the impact strength of 3D-printed PLA (polylactic acid) samples by using the Charpy test method. The used printing method is FDM (Fused Deposition Modeling) performed on a desktop printer. For each parameter changed in the study, five separate unnotched specimens were produced and tested, and the average impact strength value was taken into account. The filament rolls went through a drying process before printing and were then stored in a low-humidity environment filled with desiccant in order to minimize the effect of absorbed humidity in the filament during the experiments. The conditioning and testing of samples were performed according to the EN ISO 179-1 standard. Dimensional accuracy, print times, and filament consumption were also estimated in the study. The results revealed that the infill density, infill pattern, and wall number have a larger influence on the impact energy absorbed by the samples in comparison to the layer height, printing orientation, and the PLA filament color. The best optimization of the studied mechanical property was obtained by increasing the infill percentage and the number of walls. Applying different PLA colors has a slight effect on the impact strength, yet it should be taken into consideration when designing 3D-printed products that are intended to withstand impact. Moreover, it was found out that the studied parameters have an insignificant effect on the dimensional accuracy of the produced samples. Full article

(This article belongs to the Proceedings of The 17th International Scientific Conference on Aerospace, Automotive, and Railway Engineering)

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10 pages, 2372 KB

Open AccessProceeding Paper

Comparative Analysis of CNG and Hydrogen Effects on Exhaust Emissions in Dual-Fuel Single Cylinder Diesel Engines

by Evgeni Dimitrov, Mihail Peychev and Atanasi Tashev

Eng. Proc. 2026, 121(1), 15; https://doi.org/10.3390/engproc2025121015 - 14 Jan 2026

Viewed by 533

Abstract

This study provides a comparison between the impact of two gas fuels, compressed natural gas (CNG) and hydrogen (H₂), on the exhaust emissions of a single-cylinder diesel engine operating in dual-fuel mode. The analysis is conducted with a constant and maximum [...] Read more.

This study provides a comparison between the impact of two gas fuels, compressed natural gas (CNG) and hydrogen (H₂), on the exhaust emissions of a single-cylinder diesel engine operating in dual-fuel mode. The analysis is conducted with a constant and maximum achieved gas-to-total-fuel ratio (K = 20% and K = max) under varying load conditions, specifically at an engine speed of 2000 min⁻¹ and brake mean effective pressures ranging from 0.2 to 0.43 MPa. The results reveal that H₂ significantly improves the engine’s emissions profile compared to CNG. When H₂ is used as the secondary fuel, reductions in soot, carbon monoxide (CO), carbon dioxide (CO₂), and unburned hydrocarbons (CHs) are more pronounced. However, under certain load conditions, nitrogen oxide (NO_x) emissions are higher with H₂ than with CNG and can even surpass those observed during diesel-only operation. These findings suggest that while H₂ demonstrates superior overall emissions performance, its impact on NO_x emissions under specific conditions requires further optimization to maximize environmental benefits. Full article

(This article belongs to the Proceedings of The 17th International Scientific Conference on Aerospace, Automotive, and Railway Engineering)

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14 pages, 250 KB

Open AccessProceeding Paper

Approaches to Cybersecurity in UAS in the SORA Process: A Systematic Literature Review of Standards, Probabilistic Models, and AI Integration

by Anton Puliyski and Vladimir Serbezov

Eng. Proc. 2026, 121(1), 17; https://doi.org/10.3390/engproc2025121017 - 14 Jan 2026

Cited by 1 | Viewed by 558

Abstract

The present literature review identifies substantial research and applied potential in the combined utilization of internationally recognized information security standards, Bayesian networks, and AI-based assistants to enhance cyber resilience in Unmanned Aerial Systems (UAS) operations within the specific category defined by the SORA [...] Read more.

The present literature review identifies substantial research and applied potential in the combined utilization of internationally recognized information security standards, Bayesian networks, and AI-based assistants to enhance cyber resilience in Unmanned Aerial Systems (UAS) operations within the specific category defined by the SORA (Specific Operations Risk Assessment) methodology. The analysis reveals that while the existing literature individually addresses key components such as ISO/IEC 27001, NIST SP 800-53, MITRE ATT&CK, Bayesian models, and AI techniques, integrated methodologies that unify these elements into a comprehensive and operationally applicable framework are lacking. Particularly underrepresented is the connection to the Cyber Safety Extension of SORA, as well as the synergistic application of quantitative analysis and automation through intelligent systems. The review concludes that a systematic effort is required to develop a holistic framework that reflects the dynamic regulatory demands, operational environments, and contemporary threats facing drone technologies. Full article

(This article belongs to the Proceedings of The 17th International Scientific Conference on Aerospace, Automotive, and Railway Engineering)

10 pages, 3007 KB

Open AccessProceeding Paper

Experimental Study of Flow Around Stepped NACA 0015 Airfoils at Low Reynolds Numbers

by Ivan Dobrev, Michael Pereira, Michael Todorov and Fawaz Massouh

Eng. Proc. 2026, 121(1), 18; https://doi.org/10.3390/engproc2025121018 - 15 Jan 2026

Viewed by 546

Abstract

This study investigates the flow around Kline-Fogleman (KF) airfoils using Particle Image Velocimetry (PIV) in a wind tunnel at Reynolds number Re = 6.8 × 10⁴. Three configurations are tested: a clean NACA 0015 airfoil and two modified versions with a [...] Read more.

This study investigates the flow around Kline-Fogleman (KF) airfoils using Particle Image Velocimetry (PIV) in a wind tunnel at Reynolds number Re = 6.8 × 10⁴. Three configurations are tested: a clean NACA 0015 airfoil and two modified versions with a step on either the pressure or suction side. Velocity fields are used to calculate lift via the Kutta-Joukowski theorem. Results show that the KF airfoil with a step on the pressure side achieves a 14.8% higher maximum lift coefficient and delayed stall. In contrast, placing the step on the suction side reduces maximum lift by 4%. The KF airfoil with pressure-side step shows potential for low Reynolds number applications where higher lift and larger stall angles are required. Full article

(This article belongs to the Proceedings of The 17th International Scientific Conference on Aerospace, Automotive, and Railway Engineering)

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23 pages, 3500 KB

Open AccessProceeding Paper

Modelling Heat Recovery System for Efficiency Enhancement in Alkaline Electrolyser

by Mohamed Amin, Edward Antwi, Taimoor Khan, Romy Sommer, Qahtan Thabit and Johannes Gulden

Eng. Proc. 2026, 121(1), 19; https://doi.org/10.3390/engproc2025121019 - 16 Jan 2026

Viewed by 548

Abstract

The global energy landscape is transitioning towards cleaner solutions, with hydrogen emerging as a key energy source. To unlock hydrogen’s potential, it is crucial to prioritize the development of a more efficient, cost-effective, and environmentally friendly production process. Enhancing the efficiency and scalability [...] Read more.

The global energy landscape is transitioning towards cleaner solutions, with hydrogen emerging as a key energy source. To unlock hydrogen’s potential, it is crucial to prioritize the development of a more efficient, cost-effective, and environmentally friendly production process. Enhancing the efficiency and scalability of these technologies will not only reduce their environmental impact but also accelerate the adoption of hydrogen as a viable alternative energy solution, fostering a cleaner and more sustainable future. This paper presents a study on simulating a heat recovery system in an alkaline electrolyser consisting of 30 cells, which integrates a plate heat exchanger to preheat the water entering the system, and assessing how it affects efficiency. The study uses a thermal model, employing the concept of lumped thermal capacitance, to analyze the impact of the heat recovery system utilization on the overall performance of the electrolyser. MATLAB/Simulink was used to simulate and provide a detailed visualization of how recovery systems affect the electrolyser’s efficiency. The results of the simulations confirmed that incorporating a heat recovery system significantly improves the efficiency of alkaline electrolysers up to 8%. The study provides a promising outlook for the future of hydrogen production, emphasizing the potential of waste heat recovery systems to make green hydrogen production more viable and sustainable. Full article

(This article belongs to the Proceedings of The 17th International Scientific Conference on Aerospace, Automotive, and Railway Engineering)

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14 pages, 560 KB

Open AccessProceeding Paper

Campfire: Innovative Cost Modeling and Market Forecasting for Ammonia as a Maritime Fuel

by Mohamed Amin, Edward Antwi, Mirko Post, Romy Sommer, Qahtan Thabit and Johannes Gulden

Eng. Proc. 2026, 121(1), 20; https://doi.org/10.3390/engproc2025121020 - 16 Jan 2026

Viewed by 644

Abstract

In recent years, Ammonia has emerged as a promising carbon-free fuel alternative, offering considerable potential to reduce CO₂ emissions and contribute to the decarbonization of the transportation industry. This study focuses on the economic feasibility and market price of ammonia now and [...] Read more.

In recent years, Ammonia has emerged as a promising carbon-free fuel alternative, offering considerable potential to reduce CO₂ emissions and contribute to the decarbonization of the transportation industry. This study focuses on the economic feasibility and market price of ammonia now and in the future, highlighting the necessary infrastructure for emission-free transport operation. The project compares various production pathways for alternative fuels including hydrogen, ammonia, methanol, LNG, and diesel, considering both “green” and “gray” production methods. A key output of this research is the development of a flexible cost calculation tool, which allows users to simulate various scenarios by adjusting variables to ensure the continuity of the project. This tool enables dynamic analysis of future fuel prices and operational costs, accounting for the fluctuating electricity prices for green ammonia production and the long-term rise in CO₂ prices. Moreover, the study provides detailed cost modeling, infrastructure requirements, and refueling options for ammonia in comparison to other fuels. The findings indicate that ammonia is a promising long-term option for the maritime sector. While the adaptation to ammonia-based engines remains in the research phase, the long-term benefits of lower emissions and operating costs justify the investment in the necessary research and infrastructure, such as storage and refueling facilities. Full article

(This article belongs to the Proceedings of The 17th International Scientific Conference on Aerospace, Automotive, and Railway Engineering)

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8 pages, 2136 KB

Open AccessProceeding Paper

Improving the Productivity and Fuel Efficiency of a Wheeled Excavator by Applying an Automatic Digging System and a Tiltrotator System

by Petar Ivanov, Tsvetomir Gechev and Veselin Tsonev

Eng. Proc. 2026, 121(1), 21; https://doi.org/10.3390/engproc2025121021 - 16 Jan 2026

Viewed by 353

Abstract

The current study presents results from experimental tests of productivity, fuel consumption, and fuel efficiency of a wheeled excavator Hyundai HW160A that were performed at a construction site in Sofia, Bulgaria. The experiments happened during the span of two consecutive days, and the [...] Read more.

The current study presents results from experimental tests of productivity, fuel consumption, and fuel efficiency of a wheeled excavator Hyundai HW160A that were performed at a construction site in Sofia, Bulgaria. The experiments happened during the span of two consecutive days, and the feedback of the excavator’s operator was also taken into consideration. During the first day, the excavator operated as a conventional excavator only equipped with a bucket, while during the second day it also made use of a 3D semi-automatic digging system and a tiltrotator control system. The productivity was increased by 21.2%, the fuel consumption was decreased by 13.8%, and the fuel efficiency was increased by 32%, respectively, when applying the mentioned systems. The systems are briefly reviewed in this paper. Full article

(This article belongs to the Proceedings of The 17th International Scientific Conference on Aerospace, Automotive, and Railway Engineering)

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16 pages, 2463 KB

Open AccessProceeding Paper

Simulating Road Networks for Medium-Size Cities: Aswan City Case Study

by Seham Hemdan, Mahmoud Khames, Abdulmajeed Alsultan and Ayman Othman

Eng. Proc. 2026, 121(1), 22; https://doi.org/10.3390/engproc2025121022 - 16 Jan 2026

Viewed by 559

Abstract

This research simulates Aswan City’s urban transportation dynamics utilizing the Multi-Agent Transport Simulation (MATSim) framework. As a fast-expanding urban center, Aswan has many transportation difficulties that require extensive modeling toward sustainable mobility solutions. MATSim, recognized for its agent-based methodology, offers a detailed portrayal [...] Read more.

This research simulates Aswan City’s urban transportation dynamics utilizing the Multi-Agent Transport Simulation (MATSim) framework. As a fast-expanding urban center, Aswan has many transportation difficulties that require extensive modeling toward sustainable mobility solutions. MATSim, recognized for its agent-based methodology, offers a detailed portrayal and analysis of individual travel behaviors and their interactions within the metropolitan transportation system. This study compiled and combined many databases, including demographic data, road infrastructure, public transit plans, and travel demand trends. These data are altered to produce a realistic digital clone of Aswan’s transportation system. Simulated scenarios analyze the consequences of several actions, such as increased public transit scheduling, traffic flow management, and the adoption of alternative transport modes, on minimizing congestion and boosting accessibility. Pilot findings show that MATSim effectively captures the distinct features of Aswan’s transportation network and offers practical insights for decision-makers. The results identified some opportunities to improve mobility and promote sustainable urban growth in developing cities. This study emphasized the importance of agent-based simulations in designing future transportation systems and urban infrastructure. Full article

(This article belongs to the Proceedings of The 17th International Scientific Conference on Aerospace, Automotive, and Railway Engineering)

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10 pages, 1861 KB

Open AccessProceeding Paper

Dimensional Synthesis of a Pulse-Type Adjustable Speed Drive Based on a Six-Bar Watt II Linkage

by Rosen Mitrev, Lubomir Tsonov and Todor Todorov

Eng. Proc. 2026, 121(1), 23; https://doi.org/10.3390/engproc2025121023 - 16 Jan 2026

Viewed by 241

Abstract

This paper presents a method for dimensional synthesis of a pulse-type adjustable speed mechanical drive, realized through a Watt II six-bar linkage combined with an overrunning clutch. The goal is to achieve a transmission ratio that varies smoothly and linearly by adjusting the [...] Read more.

This paper presents a method for dimensional synthesis of a pulse-type adjustable speed mechanical drive, realized through a Watt II six-bar linkage combined with an overrunning clutch. The goal is to achieve a transmission ratio that varies smoothly and linearly by adjusting the angle of a control lever, while meeting kinematic, geometric, and force constraints. The kinematic characteristics are derived analytically using vector-loop equations, enabling comparison with a predefined linear reference function. An optimization problem is formulated to minimize the maximum deviation between the actual and reference output angles across the entire operating interval. The solution employs a metaheuristic algorithm for global search followed by a local refinement phase. Three optimization scenarios are analyzed, each with different levels of design freedom regarding the parameters defining the linear reference function. The results demonstrate a clear trade-off between accuracy and functional tunability, highlighting the most effective balance for practical applications. This approach can be used for designing mechanical drives with adjustable speed features and can be applied to other complex linkage systems. Full article

(This article belongs to the Proceedings of The 17th International Scientific Conference on Aerospace, Automotive, and Railway Engineering)

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12 pages, 4944 KB

Open AccessProceeding Paper

Hysteresis Modeling of Automotive Electrohydraulic Semi-Active Dampers Using Tangent Functions and Simulation-Based Ride Comfort Evaluation

by Mert Büyükköprü, Erdem Uzunsoy, Zafer Satar and Yakup Küçük

Eng. Proc. 2026, 121(1), 24; https://doi.org/10.3390/engproc2025121024 - 19 Jan 2026

Viewed by 589

Abstract

This study develops a hyperbolic tangent-based model for the hysteretic behavior of automotive grade electrohydraulic semi-active dampers. Model parameters were identified from experimental force–velocity data gathered under sinusoidal excitations across 1–6 Hz and 0.38–1.6 A. The calibrated model was integrated into an IPG [...] Read more.

This study develops a hyperbolic tangent-based model for the hysteretic behavior of automotive grade electrohydraulic semi-active dampers. Model parameters were identified from experimental force–velocity data gathered under sinusoidal excitations across 1–6 Hz and 0.38–1.6 A. The calibrated model was integrated into an IPG CarMaker 13.0/Simulink 2022b co-simulation to assess performance under ISO-compliant road profiles and realistic driving scenarios. Comparative analysis with conventional nonlinear damper models was conducted, focusing on ride comfort metrics such as vertical acceleration, pitch rate, and roll rate. The results demonstrate that the proposed model provides improved fidelity in replicating real damper behavior and enables more realistic assessment of semi-active suspension performance in virtual vehicle development platforms by providing reduced vertical acceleration errors by >5 dB (2–6 Hz) compared to nonlinear models. Full article

(This article belongs to the Proceedings of The 17th International Scientific Conference on Aerospace, Automotive, and Railway Engineering)

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14 pages, 1748 KB

Open AccessProceeding Paper

CubeSat Debris Capture Using Power Rate Reaching Law Sliding Mode Control (PRRL-SMC)

by Mahsa Azadmanesh, Ali Mari Oryad and Krasin Georgiev

Eng. Proc. 2026, 121(1), 25; https://doi.org/10.3390/engproc2025121025 - 19 Jan 2026

Viewed by 185

Abstract

Active Debris Removal (ADR) missions demand precise and rapid controllers that lower collision risks specifically in the capture phase of tumbling objects. Sliding Mode Control (SMC), in general, offers robustness against model uncertainties. However, traditional reaching laws often face slow convergence when the [...] Read more.

Active Debris Removal (ADR) missions demand precise and rapid controllers that lower collision risks specifically in the capture phase of tumbling objects. Sliding Mode Control (SMC), in general, offers robustness against model uncertainties. However, traditional reaching laws often face slow convergence when the chaser is too far from the target state. In this paper, we address this particular limitation and present the first application of Power Rate Reaching Law Sliding Mode Control (PRRL-SMC) to the 6-DOF coupled dynamics of a CubeSat-based debris capture mission in both the pre-capture tracking and post-capture stabilization phases in the case of tumbling debris. To show the strength of our work, we evaluate the proposed controller against Proportional–Derivative (PD), Linear Quadratic Regulator (LQR), second-order SMC (SOSMC), and terminal SMC (TSMC) for the pre-capture tracking and post-capture stabilization phases. By numerical simulations we show that PRRL-SMC reduces convergence time extremely and achieves stable capture in 7.6 s. This time it is 24.6 s for LQR and 28.1 s for SOSMC. The controller also handles the abrupt inertia variations of the combined stack post-capture successfully. This is efficient for proximity operations because of their importance in timing and fuel conservation. Full article

(This article belongs to the Proceedings of The 17th International Scientific Conference on Aerospace, Automotive, and Railway Engineering)

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14 pages, 2906 KB

Open AccessProceeding Paper

Onboard Deep Reinforcement Learning: Deployment and Testing for CubeSat Attitude Control

by Sajjad Zahedi, Jafar Roshanian, Mehran Mirshams and Krasin Georgiev

Eng. Proc. 2026, 121(1), 26; https://doi.org/10.3390/engproc2025121026 - 20 Jan 2026

Viewed by 419

Abstract

Recent progress in Reinforcement Learning (RL), especially deep RL, has created new possibilities for autonomous control in complex and uncertain environments. This study explores these possibilities through a practical approach, implementing an RL agent on a custom-built CubeSat. The CubeSat, equipped with a [...] Read more.

Recent progress in Reinforcement Learning (RL), especially deep RL, has created new possibilities for autonomous control in complex and uncertain environments. This study explores these possibilities through a practical approach, implementing an RL agent on a custom-built CubeSat. The CubeSat, equipped with a reaction wheel for active attitude control, serves as a physical testbed for validating RL-based strategies. To mimic space-like conditions, the CubeSat was placed on a custom air-bearing platform that allows near-frictionless rotation along a single axis, simulating microgravity. Unlike simulation-only research, this work showcases real-time hardware-level implementation of a Double Deep Q-Network (DDQN) controller. The DDQN agent receives real system state data and outputs control commands to orient the CubeSat via its reaction wheel. For comparison, a traditional PID controller was also tested under identical conditions. Both controllers were evaluated based on response time, accuracy, and resilience to disturbances. The DDQN outperformed the PID, showing better adaptability and control. This research demonstrates the successful integration of RL into real aerospace hardware, bridging the gap between theoretical algorithms and practical space applications through a hands-on CubeSat platform. Full article

(This article belongs to the Proceedings of The 17th International Scientific Conference on Aerospace, Automotive, and Railway Engineering)

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9 pages, 727 KB

Open AccessProceeding Paper

Legal Frameworks for Asteroid Mining: Techno-Economic Impacts and Regulatory Needs

by Hamideh Azimzadeh, Mahsa Azadmanesh, Radina Nikolova and Roya Asiaei

Eng. Proc. 2026, 121(1), 27; https://doi.org/10.3390/engproc2025121027 - 20 Jan 2026

Viewed by 1202

Abstract

The current space law does not clarify the asteroid mining problem enough. This paper presents a techno-economic analysis to show how legal certainty impacts the profitability and overall investment in asteroid mining projects. Our analysis reveals that clear legal frameworks reduce perceived investment [...] Read more.

The current space law does not clarify the asteroid mining problem enough. This paper presents a techno-economic analysis to show how legal certainty impacts the profitability and overall investment in asteroid mining projects. Our analysis reveals that clear legal frameworks reduce perceived investment risk significantly. We have introduced a financial model that demonstrates how different legal scenarios, specifically those offering clear frameworks and benefit-sharing mechanisms, lead to positive Net Present Values. We thereby encourage fair resource distribution and opportunities within a regulated system, as an environment with high legal uncertainty results in negative Net Present Values, and show significant financial risk. Full article

(This article belongs to the Proceedings of The 17th International Scientific Conference on Aerospace, Automotive, and Railway Engineering)

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15 pages, 362 KB

Open AccessProceeding Paper

An Integrated Model for the Electrification of Urban Bus Fleets in Public Transport Systems

by Velizara Pencheva, Asen Asenov, Aleksandar Georgiev, Kremena Mineva and Mladen Kulev

Eng. Proc. 2026, 121(1), 28; https://doi.org/10.3390/engproc2025121028 - 20 Jan 2026

Viewed by 315

Abstract

The article explores the current challenges and prospects for the electrification of the bus fleet in urban passenger transport, with a particular focus on the municipal operator Municipal Transport Ruse EAD. The study is motivated by the growing importance of sustainable mobility and [...] Read more.

The article explores the current challenges and prospects for the electrification of the bus fleet in urban passenger transport, with a particular focus on the municipal operator Municipal Transport Ruse EAD. The study is motivated by the growing importance of sustainable mobility and the European Union’s policy framework aimed at decarbonization of urban transport systems. A mixed-integer linear programming (MILP) model is developed to optimize the investment and operational strategies for the gradual replacement of diesel buses with electric ones, taking into account capital expenditures, operational costs, charging infrastructure, and environmental benefits. Scenario analysis is employed to compare six different pathways of fleet electrification, ranging from partial to full transition within a defined planning horizon. The results highlight significant trade-offs between financial feasibility and ecological impact, illustrating that an accelerated electrification strategy yields the largest emission reductions but requires substantial upfront investment. Conversely, gradual transition scenarios demonstrate better budget alignment but achieve lower environmental benefits. The discussion emphasizes the practical applicability of the model for municipal decision-makers, offering a tool for strategic planning under economic and ecological constraints. The paper concludes that sustainable electrification of municipal bus fleets requires a balanced approach that aligns environmental objectives with financial and operational capacities. Full article

(This article belongs to the Proceedings of The 17th International Scientific Conference on Aerospace, Automotive, and Railway Engineering)

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10 pages, 2300 KB

Open AccessProceeding Paper

On the Aerodynamic Characteristics of the Aurel Persu Car

by Adrian Clenci, Amélie Danlos, Ivan Dobrev and Victor Iorga-Simăn

Eng. Proc. 2026, 121(1), 29; https://doi.org/10.3390/engproc2025121029 - 21 Jan 2026

Viewed by 392

Abstract

This study investigates the aerodynamics of Romanian engineer Aurel Persu’s car through wind tunnel experiments involving force measurements, Particle Image Velocimetry (PIV), and CFD simulations. Tests using scale models revealed significant flow separation behind the cabin. The measured drag coefficient is C_D [...] Read more.

This study investigates the aerodynamics of Romanian engineer Aurel Persu’s car through wind tunnel experiments involving force measurements, Particle Image Velocimetry (PIV), and CFD simulations. Tests using scale models revealed significant flow separation behind the cabin. The measured drag coefficient is C_D = 0.364 at 33 m/s, showing moderate sensitivity to Reynolds number. CFD simulations using the unsteady STAR CCM+ solver with a k-ω SST turbulence model produced a slightly lower drag coefficient (C_D = 0.353) due to delayed separation. The good agreement between experimental and numerical results validates the modeling approach and highlights aerodynamic limitations around the front and roof. Despite these limitations, the model achieved aerodynamic performance that was exceptional for its time and remained competitive with mainstream production vehicles well into the latter half of the 20th century. Full article

(This article belongs to the Proceedings of The 17th International Scientific Conference on Aerospace, Automotive, and Railway Engineering)

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14 pages, 1862 KB

Open AccessProceeding Paper

Obstacle Avoidance for Multirotor Urban Air Mobility via Prediction-Based Control Barrier Functions

by Ali Mesbah, Jafar Roshanian and Dimitar Ginchev

Eng. Proc. 2026, 121(1), 30; https://doi.org/10.3390/engproc2025121030 - 2 Feb 2026

Viewed by 287

Abstract

This paper applies the recently developed Prediction-Based Control Barrier Functions (PB-CBFs) to the obstacle avoidance problem for multirotor air taxis in Urban Air Mobility (UAM). Unlike conventional Control Barrier Functions (CBFs), PB-CBFs incorporate escape path predictions into the formulation, facilitating safe controller design [...] Read more.

This paper applies the recently developed Prediction-Based Control Barrier Functions (PB-CBFs) to the obstacle avoidance problem for multirotor air taxis in Urban Air Mobility (UAM). Unlike conventional Control Barrier Functions (CBFs), PB-CBFs incorporate escape path predictions into the formulation, facilitating safe controller design for dynamical systems with high relative degree and enabling safety under strict control constraints. We first review the PB-CBF framework, then formulate the safety requirements specific to the collision avoidance problem and derive the corresponding invariance conditions. Finally, we validate our approach through simulation of the obstacle avoidance scenario, demonstrating the efficacy of PB-CBFs in ensuring safety in UAM operations and providing additional insight into the mechanism by which predictions are leveraged to enforce safety. Full article

(This article belongs to the Proceedings of The 17th International Scientific Conference on Aerospace, Automotive, and Railway Engineering)

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13 pages, 2848 KB

Open AccessProceeding Paper

Prediction of the Spare Parts Range Based on Time and Economic Factors

by Oleksandr Kravchenko, Ján Dižo, Andrej Suchánek and Kristína Kozáková

Eng. Proc. 2026, 121(1), 31; https://doi.org/10.3390/engproc2025121031 - 3 Feb 2026

Viewed by 386

Abstract

This work examines the results of research into internal combustion engine malfunction using the example of a vehicle control group of a specific transport company during the warranty and post-warranty periods. Studies have established that the most frequently encountered distribution laws for random [...] Read more.

This work examines the results of research into internal combustion engine malfunction using the example of a vehicle control group of a specific transport company during the warranty and post-warranty periods. Studies have established that the most frequently encountered distribution laws for random variables during vehicle operation are normal, Weibull, log-normal, and exponential, and research has determined the patterns of units’ malfunctions and the internal combustion engine parts. The reliable operation of vehicles is achieved by maintaining a stock of spare parts, the size and range of which play an important part in the ensuing costs. It is important to forecast the need for spare parts to improve the efficiency of vehicle operation. A common drawback of forecasting methods, from the point of view of material resource management is the limited consideration of important factors such as the spare parts’ delivery time from the moment of ordering, the time frame for performing the repair work, and the spare parts’ cost. We determined that 65.7% of spare parts are delivered within one day, and 15.7% are delivered within 2 weeks. Further, it takes up to 3 h for the replacement of 82.45% of the spare parts. To determine the need for spare parts, it is important to consider the actual operational reliability and the listed factors to enable optimizing the repair fund of the motor transport enterprise and increase the efficiency of use of rolling stock. Full article

(This article belongs to the Proceedings of The 17th International Scientific Conference on Aerospace, Automotive, and Railway Engineering)

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11 pages, 1814 KB

Open AccessProceeding Paper

Urban Hybrid Electric Vehicle with Kinetic Energy Storage System and Friction Transmission

by Venelin Jivkov, Kostadin Stoichkov and Konstantin Dimitrov

Eng. Proc. 2026, 121(1), 32; https://doi.org/10.3390/engproc2025121032 - 2 Feb 2026

Viewed by 198

Abstract

The subject of this study is the dynamic analysis of the energy flow in the transient mode of the movement of the vehicle with a kinetic accumulator, implemented with a purely mechanical transmission. The elements of which include—a flywheel, planetary gears with two [...] Read more.

The subject of this study is the dynamic analysis of the energy flow in the transient mode of the movement of the vehicle with a kinetic accumulator, implemented with a purely mechanical transmission. The elements of which include—a flywheel, planetary gears with two degrees of freedom, some ordinary gears, a friction mechanism with a variable transmission ratio (CVT), and a certain number of brake clutches, etc. A control algorithm is proposed; the differential equations of motion are derived and solved. The effectiveness and applicability of such a purely mechanical transmission for accumulating and realizing energy during braking and accelerating of the electro-mobile are proven, in which it is possible to extend the range by up to 12–14%. Full article

(This article belongs to the Proceedings of The 17th International Scientific Conference on Aerospace, Automotive, and Railway Engineering)

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