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Institute of Fundamental Technological Research Polish Academy of Sciences
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Preface to a selection of papers presented at the SiMRTRANS Scientific and Technical Conference: “Innovative Solutions in Transport”, which took place at the Warsaw University of Technology, Faculty of Automotive and Construction Machinery Engineering, on September 19, 2024.
SIMRTRANS: Innovative solutions in means of transport
Copyright (c) 2025 Dariusz WIĘCKOWSKI https://creativecommons.org/licenses/by/4.0
Analysis of a Variable Geometry Radial Inflow Turbine Using 1D Mean-line Model
Despite great progress in 3D computational fluid dynamics (CFD), mathematical modeling used for turbomachinery analysis, the prediction of flow parameters in the rotor (impeller) of radial inflow turbines using existing turbulence models often yields unsatisfactory results. This is because real physical processes related to turbulence are very complex. Other limitations of CFD tools include numerical errors due to finite difference approximations. Thus, for the analysis and optimization of radial inflow turbines, empirical loss correlations applied to a mean-line 1D mathematical model can provide faster and more accurate results compared to CFD simulations. In this study, a 1D approach was used for the mathematical modeling of gas flow in a variable geometry radial inflow turbine with a vaneless volute distributor (VVD). The variable geometry turbine (VGT) was part of a turbocharging system. Combustion engine operation mode with high-power and low-crankshaft rotational speed was chosen, as engine performance under this condition is sensitive to turbocharger adjustment in terms of break specific fuel consumption (BSFC) and other critical parameters. An experimentally-based approach was used where gas flow characteristics in the VGT were calculated under real engine-turbocharger operating conditions. Accordingly, exhaust gas parameters were first measured on an experimental setup. Mathematical modeling then allowed to assess how adjustment in VGT influenced turbine indices, including loss distribution across the stage. It was also validated in this study that during high-load and low-crankshaft operating conditions of the compression ignition (CI) engine, it is recommended to minimize the cross-sectional area at the outlet of the volute acceleration section in the VGT. This adjustment results in better fuel efficiency and lower thermal loads on turbine components, despite a slight reduction in the turbine’s overall efficiency.
Copyright (c) 2025 Dmytro SAMOILENKO https://creativecommons.org/licenses/by/4.0
Performance of a Hybrid Ichthyoid-Waterjet Articulated Propulsor
The concept of a bioinspired ichthyoid-waterjet propulsor for autonomous underwater vehicles (AUVs) is investigated. The propulsor consists of an articulated fluid-conveying pipe with a propulsive fin at the end. Water drawn into the hull is accelerated to a supercritical velocity, which yields flutter vibrations of the propulsor resembling the motion of a swimming fish. The fin acts on the surrounding water and generates thrust. At the same time, the ejected water produces recoil. Using the proposed dynamical model, three types of propulsors for different swimming speeds are investigated. At low swimming speeds, the propulsive force generated by the propulsors can be up to 30% higher than the thrust of a conventional waterjet propulsor with the same physical parameters. However, this advantage in the generated thrust decreases with the swimming speed increase. The results are obtained by analyzing the approximation of the bifurcating solution and numerical simulations of the differential equation governing the dynamics.
Copyright (c) 2025 Tomasz SZMIDT https://creativecommons.org/licenses/by/4.0
Analysis of the Braking Process for Curvilinear Motion of Vehicle
Road incident reconstruction frequently includes the possibility of avoiding a collision. To perform such analysis, it is necessary to compare the available distance with the minimum braking distance. Therefore, to avoid a collision, the braking distance must be shorter than the available distance. The braking distance depends on parameters such as tyre-to-road adhesion coefficient, the initial velocity of a vehicle, the driver’s reaction time and the time needed to reach full braking force. However, the problem is that, in practice, none of these values are known during traffic incident reconstruction. As a result, the estimated vehicle velocity is uncertain. This is due to the method used to reconstruct a road incident (and the errors in the evidence data). The tyre-to-road adhesion coefficient depends on many factors and can be estimated with limited accuracy, usually ±0.1. The uncertainty of the estimate is approximately ±15%. The reaction time of a specific driver under the conditions present during a road incident is not precisely known. Therefore, an average value for most drivers is taken into account. It is assumed that a healthy driver’s reaction time should not exceed this value, and a longer reaction time is associated with incorrect driving behavior. The time taken to reach full braking force in a real situation is also unknown. Usually, average values are taken from the literature, without the analysis of a technical condition of a vehicle. This article considers the mechanics of vehicle braking, taking into account the action of lateral forces on this vehicle while considering a curved track. The maximum deceleration during braking is determined analytically, and a condition is formulated to indicate whether it is justified to use an advanced computational model instead of the basic one described in the literature. The analysis includes some dimensionless parameters describing the position of the center of gravity, tangential forces between the tyre and the road, the intensity of turning and braking, suspension characteristics, and asymmetrical mass distribution. This dimensionless approach may be useful for applying the presented analysis of braking on the road arc in accident reconstruction, especially when comparative analysis is recommended.
Copyright (c) 2025 Piotr FUNDOWICZ, Hubert SAR, Mateusz BRUKALSKI, Michał ABRAMOWSKI https://creativecommons.org/licenses/by/4.0
Energy Efficiency of an LPG-Powered Extended-Range Electric Vehicle
This paper deals with energy efficiency evaluation of an extended range electric vehicle (EREV) equipped with a range extender (REX) powered by liquefied petroleum gas (LPG). The investigation is based on simulation, with key input data derived from empirical studies carried out by the authors. It includes four target driving ranges (200, 300, 400, 500 km), six driving cycles (WLTC 3b, FTP-75, CLTC-P, Artemis 130, NYCC, HWFET) and three battery size variants for the WLTC 3b cycle. The influence of the these factors on the overall efficiency and specific energy consumption of the EREV is assessed. The results are analyzed in terms of the number of REX activations per 100 km and the total REX operating time.
Copyright (c) 2025 Paweł KRAWCZYK, Artur KOPCZYŃSKI, Jakub LASOCKI https://creativecommons.org/licenses/by/4.0
Determination of Operating Conditions of a Probe Block Designed for Fault Diagnostics in Rail Heads
In this paper, the key parameters influencing the proper operation of ultrasonic probes for railway rails diagnostics are determined. The goal is to test a set of ultrasonic probes under conditions occurring at high diagnostic speeds. Four issues are studied in more detail. The probe block-rail contact force required to obtain maximum echo level is determined. In the authors’ opinion, the key aspect is the design of the water irrigation nozzle shape in order to produce a laminar couplant flow under the probes. The dependence of the amplitude of the recorded echo on the coupling layer thickness is experimentally investigated. The population of registered signal samples is processed to determine the testing speed limit, which resulted from the loss of data validation ability. The speed limit is calculated based on the average value of the amplitude of the measured signal and the standard deviation of the registered population of amplitudes. The conducted research allows the authors to conclude that the instrumentation they developed enables the recording of an ultrasonic signal propagating through the tested rail at scanning speed of up to 100 km/h.
Copyright (c) 2025 Zbigniew RANACHOWSKI, Sławomir MACKIEWICZ, Tomasz KATZ, Tomasz DĘBOWSKI, Grzegorz STARZYŃSKI, Marcin LEWANDOWSKI, Łukasz ANTOLIK https://creativecommons.org/licenses/by/4.0
The Development Features and Design of a Vibratory Gyroscope with a Metallic Cylindrical Resonator
This paper presents the results of developing a vibratory gyroscope with a cylindrical resonator made of Elinvar alloy. The vibratory gyroscope operates in three modes. These modes include rate mode, rate-integrating mode, and a new, third, differential mode. The differential mode can simultaneously measure two opposite angular rates, Ω and −Ω. A block diagram of the standing wave control system for each mode is presented. The advantages and disadvantages of each of the modes are analyzed. A triple-mode gyro is proposed. The results of experimental studies and simulation data are also presented.
Copyright (c) 2025 Valerii CHIKOVANI, Serhii HOLOVACH, Hryhorii STROKACH, Vadym AVRUTOV https://creativecommons.org/licenses/by/4.0
Dynamic Eccentricity Modeling of a Switched Reluctance Motor
The switched reluctance motor (SRM), known for its robust and simple construction, is widely utilized in critical applications. This study investigates the impact of rotor dynamic eccentricity on the motor's current signal. Our research introduces a straightforward diagnostic method to detect and quantify dynamic eccentricity by analyzing the current signal spectrum. This approach specifically focuses on identifying amplitude increases in characteristic additional harmonics, leveraging fundamental electromagnetic transformations to eliminate the need for complex algorithms. Through coupled computer simulations, combining a finite element analysis model (FEMM) with dynamic equation solutions in Simulink, this study identifies specific eccentricity ranges and their corresponding characteristic current values, offering a reliable tool for SRM condition monitoring.
Copyright (c) 2025 Jakub LORENCKI, Adrian CHMIELEWSKI https://creativecommons.org/licenses/by/4.0
Comparison of Gantry Drive and Crankset: A Pilot Study Across a Broad Power Spectrum
The gantry drive was originally invented in 1948 in England and was “rediscovered” in Poland in 2019 while working on lightweight, personal, compact vehicles. In this study, the gantry drive is subjected to dynamic tests against the background of the commonly known crankset. The aim of the dynamic tests is to develop power curves and measure efficiency for various human-mechanism systems, i.e., the hand-driven crankset, the leg-driven crankset, and the gantry drive. Pilot dynamic tests have shown many advantages of the gantry over the crankset; in general, test participants were much less tired when using the gantry drive.
Copyright (c) 2025 Łukasz BEREŚ, Marcin OBSZAŃSKI, Paweł PYRZANOWSKI https://creativecommons.org/licenses/by/4.0
Prediction of Soil Liquefaction Using Machine Learning Approaches
In the geotechnical engineering field, the assessment of liquefaction potential is a critical aspect of site evaluation. This work focuses on the application of support vector machines (SVM) to improve the accuracy of liquefaction potential evaluation. Input data were collected from the authors' previous study and include parameters such as groundwater table (GWT), depth, fineness content, peak ground acceleration (PGA), corrected SPT-N value, total stress, and effective overburden stress. Radial basis function (RBF), linear, polynomial, and sigmoid are the four SVM kernel functions that are examined in this study to model liquefaction-related data using three approaches: grid search cross-validation, k-fold cross-validation, and fuzzy c-clustering means (FCM). Several performance metrics, including accuracy, precision, recall, and the area under the receiver operating characteristics (ROC) curve (AUC), among others, are used to evaluate the developed machine learning (ML) models. The linear and polynomial functions, for the grid search cross-validation approach, show higher performance with an accuracy of 94.64%, recall of 95.55%, F1-score of 96.63, and AUC of 0.99 on the testing data. For the k-fold partitioning approach, the RBF yields higher performance metrics compared to the other three functions, with an accuracy of 92.73%, precision of100%, F1-score of 95.0%, and AUC of 0.98. In the FCM technique, the linear and polynomial kernels again yield greater accuracy, precision, F1-score, and specificity, while, the AUC values of the sigmoid and RBF kernels are higher. The current analysis recommends the RBF over other mathematical functions based on the k-fold partitioning technique after evaluating all performance matrices.
Copyright (c) 2025 Md. Mahabub RAHMAN, Md. Belal HOSSAIN, Abu SAYED https://creativecommons.org/licenses/by/4.0
Effect of Initial Scratch on Ship Bottom Plate Corrosion Rate and Structural Crashworthiness in Grounding Incidents
Hitting an object in the ocean can peel off the coating on a ship's plate. The exposed plate can be vulnerable to corrosion because it is exposed to the environment and seawater, which can degrade its strength. So, the crashworthiness of the bottom plate should be evaluated in the event of a grounding incident. The ratio of the scratch area and the number of stripes are used as experimental variables. Based on seawater corrosion experiments, the plate's corrosion rate increases quadratically with the scratch area, which is then used for grounding simulations. Eighteen grounding scenarios, based on scratch size, dimensions, and corrosion exposure, reveal that only two or three stripes significantly reduce the plate’s strength in simulations. In addition, in the case of two or three stripes of scratches, corrosion further reduces the plate’s strength in the grounding simulations. This plate has limited space in the vertical direction, which influences the horizontal stripe of scratches and affects the plate's strength in grounding simulation, as compared to the vertical stripes. Besides this, the pattern of crack propagation depends on the reaction force.
Copyright (c) 2025 Ocid MURSID, Dean Nadhif ALFARIS, Tuswan TUSWAN, Ahmad Fauzan ZAKKI, Aulia WINDYANDARI, Karno R. MALAU, Haris NUBLI https://creativecommons.org/licenses/by/4.0
Multi-Objective Design of a Pneumatic Adaptive Impact Absorber
This manuscript proposes a multicriteria approach to the design optimization of adaptive pneumatic impact absorbers. The considered absorber consists of two sealed chambers separated by a piston with an internal valve. Proper valve control affects gas flow between the chambers and ensures a flat reaction force profile over a possibly long piston stroke. The design of such an absorber is defined by three parameters: initial gas pressure, diameter, and length. For a given range of impact conditions, the worst-case maximum deceleration and maximum mass flow rate are used as design criteria in a multicriterial minimization problem. Solutions to this problem provide an optimal balance between impact absorption performance and the technical requirements the valve must meet. An example is considered, which illustrates the Pareto-optimal solutions in the design space and the complex interdependency between initial pressure and absorber diameter at each absorber length. The results demonstrate that a proper choice of design parameters can result in significant performance improvements.
Copyright (c) 2025 Rafal WISZOWATY, Cezary GRACZYKOWSKI, Grzegorz MIKUŁOWSKI, Jan HOLNICKI-SZULC, Zbigniew WOŁEJSZA, Anita ORŁOWSKA-GAŁĘZIA, Łukasz JANKOWSKI https://creativecommons.org/licenses/by/4.0
Assessment of Methods for Determining Vehicle Emission Characteristics
This paper presents an analysis of pollutant emissions (carbon monoxide, hydrocarbons, nitrogen oxides, methane, non-methane volatile organic compounds and carbon dioxide) from a passenger car, particularly under real-world driving conditions, to more accurately model the impact of transport on the environment. These pollutants were selected due to their regulatory relevance and significant environmental and health impacts. A mathematical model developed in this study was used to estimate emissions, with vehicle speed identified as a key parameter influencing emission levels. Various speed ranges and their impact on emission levels were considered during parametric identification. Since the relationship between pollutants and speed is nonlinear, the least squares method was applied to estimate model parameters for the different pollutants. The model developed in the paper allows for precise emission prediction for various vehicle use scenarios. The scenarios analyzed include urban driving conditions with vehicle speeds not exceeding 60 km/h. The selected speed profile was first recorded in real-world traffic using a portable emissions measurement system (PEMS) and subsequently reproduced on a chassis dynamometer to ensure test repeatability under controlled laboratory conditions.
Copyright (c) 2025 Piotr LASKOWSKI, Edward KOZŁOWSKI, Magdalena ZIMAKOWSKA-LASKOWSKA, Piotr WIŚNIOWSKI https://creativecommons.org/licenses/by/4.0
The Development of Green Polylactic Acid (PLA)Composites for Wastewater Treatment – A Review
Polylactic acid (PLA) is a biodegradable polyester derived from renewable resources, recognized for its environmental sustainability and versatile properties. Its applications spam the biomedical, textile, and packaging industries and, more recently, wastewater treatment. This review explores recent advancements in the use of PLA and its composites for wastewater treatment, emphasizing their effectiveness, modification techniques to enhance performance, and future research directions. A thorough literature review was conducted, covering the past decade studies, and, including research articles, reviews, and case studies on PLA’s application in wastewater treatment and comparative performance against other adsorbents. Although PLA’s natural adsorption capacity is limited, it has demonstrated significant potential for removing contaminants such as heavy metals, organic dyes, and other organic pollutants. Various modifications, including surface chemical changes, physical blending with nanomaterials, and more, have notably improved its adsorption performance. Modified PLA composites thus present a viable and sustainable solution for wastewater treatment. Continued research is essential to further optimize these modifications, explore novel composite materials, develop scalable technologies, and assess long-term environmental impacts. This review offers a critical synthesis of current knowledge on PLA-based materials in wastewater treatment, aiming to inform and guide future research in sustainable water purification technologies.
Copyright (c) 2022 Andriy Anta KACARIBU, Yuliani AISYAH, Febriani FEBRIANI, Darwin DARWIN https://creativecommons.org/licenses/by/4.0
Research on Liquid Flow Resistance in Flow and Centrifugal Extraction Reactors
This paper presents research that formed the basis for the development of a low-temperature centrifugal extraction reactor. This reactor is used to obtain medicinal substances from herbs, where key parameters include extraction time, temperature, and the velocity of the solvent that flows through the dried herbs. An important parameter for performing simulation studies was the assessment of the medium flow characteristics through the dried medicinal herb material. For this purpose, a flow reactor was developed and tested. The first part of the paper discusses the results of numerical and experimental studies on liquid flow through the extraction reactor. This part of the work was carried out in order to determine the parameters related to the resistance of liquid flow through dried medicinal herbs. This resistance of the liquid flow through the herbs affects the limitation of its velocity and has a direct impact on the efficiency of the process. In the second part of the paper, the results obtained from the flow reactor experiments were used for numerical investigations of the centrifugal extractor drum.
Copyright (c) 2025 Jędrzej MĄCZAK, Dmytro SAMOILENKO, Michal MAKOWSKI, Lech KNAP https://creativecommons.org/licenses/by/4.0
Effect of Turbulent Oil Film on the Dynamic Characteristics of 2-lobe Journal Bearings
Turbogenerators in power plants utilize two-lobe journal bearings, which can carry large loads with good stability at the speeds typically encountered in the power industry. These bearings feature the profiles such as elliptical, offset, cylindrical or pericycloidal. The design of these bearings ensures proper load capacity, favorable thermal conditions for the oil film, and stable operation of the associated turbounits. However, the design of these bearings should be supported by calculations that account for turbulence generated in the oil film. This paper presents the results of dynamic characteristic calculations for four types of two-lobe journal bearings operating under adiabatic laminar or turbulent flow conditions in the lubricating gap. The dynamic characteristics, expressed as the stiffness and damping coefficients of the oil film, were obtained using the perturbation method. Stability ranges for a simple symmetric rotor were determined for the considered bearings. A numerical algorithm for the iterative solution of the Reynolds, energy and viscosity equations was employed to calculate the oil film forces, which formed the basis for the bearing’s dynamic characteristics. These investigations were carried out assuming the static equilibrium position of the journal.
Copyright (c) 2025 Stanislaw Kazimierz STRZELECKI https://creativecommons.org/licenses/by/4.0
Impact of Spin Slip Conditions on the Axisymmetric Rotation of a Spherical Particle in a Couple Stress Fluid Within a Cavity
This paper investigates the effect of spin slip condition on the flow of a couple stress fluid between two concentric spheres. The spherical particles rotate about the z-axis with different angular velocities and under the assumption of low Reynolds numbers. To solve the governing equations, we impose tangential slip and couple stress spin slip boundary conditions at the surfaces of the particle and the cavity wall. The nondimensional torque is computed, tabulated and graphically analyzed for various values of the separation parameter, couple stress viscosity, angular velocity ratio, tangential slip, and couple stress spin slip parameters. Our findings indicate that torque value increases with higher values of the couple stress viscosity parameter, separation parameter, tangential slip parameter, and spin slip parameter. However, the torque decreases as the angular velocity ratio increases. Furthermore, our results agree with previously published findings for cases with vanishing tangential slip and spin slip at the particle and cavity surfaces.
Copyright (c) 2025 Shekhar NISHAD, Krishna Prasad MADASU https://creativecommons.org/licenses/by/4.0
Numerical and Experimental Analysis of Tuning Three Selected Types of Acoustic Helicoidal Resonators with 90-Degree Duct Elbow
This work presents the results of numerical and experimental analyses regarding the tuning of three selected acoustic helicoidal resonators using a 90-degree elbow in a cylindrical duct. The elbow is placed directly at the end of the resonators, which were additionally rotated about the duct axis at a specific angle (45° angle change in the numerical analysis and 90° angle change in the experiment). Three resonators with the same helicoid pitch-to-duct diameter ratio of s/d = 1.976 but with different numbers of turns n of 0.671, 0.695, and 1.0 were selected for analysis. They represent three different transmission loss (TL) characteristics in the frequency domain. In the considered system of helicoidal resonators and a 90-degree duct elbow, it was found that the selected resonators can be tuned by rotating them, effectively covering nearly the entire range of their characteristic sound attenuation resulting from acoustic resonance.
Copyright (c) 2025 Wojciech ŁAPKA https://creativecommons.org/licenses/by/4.0
A Concept of a Vision System for Position DeterminationUsing Spatial-Time-Frequency Analysis
This paper presents the concept of a vision system designed to determine the position of a camera within a given coordinate system. The system focuses on identifying pulsating light markers in images recorded by the camera. These markers are characterized by specific colors, pulsation frequencies and known locations. Detection is achieved using a spatial-time-frequency processing method developed by the authors. The identified markers serve as input data for a mathematical model that determines the camera’s position within the reference system. The article discusses the theoretical foundations of the proposed system design. The system was subjected to testing to verify its operational accuracy and precision in position determination. The results of these tests are presented. The article concludes with a summary of the work and a discussion of the system’s further development and practical applications.
Copyright (c) 2022 Piotr MIŚ, Przemysław SZULIM, Jędrzej MĄCZAK https://creativecommons.org/licenses/by/4.0
Assessment of GFRP Reinforcement Bars Condition Based on Elastic Wave Propagation
New technologies in construction constitute a crucial element of effective development. Contemporary trends have led to increasing interest in composite materials, mainly due to their unique properties. The flexibility in shaping composite materials enables the production of reinforcing bars, providing a viable alternative to the widely used steel bars. The implementation of innovative solutions necessitates monitoring the performance of structures. Using information on the propagation of elastic waves is one of the non-destructive testing (NDT) methods for observing the construction behavior. An effort to employ this technique in the assessment of the anchoring condition and stress evaluation in glass fiber-reinforced polymer (GFRP) bars is presented in this study. During laboratory testing, samples of ribbed bars with diameters of f6 mm, f10 mm, and f16 mm were used (a total of 20 bars). Measurements were performed using laser Doppler vibrometry and piezoelectric transducers (PZT). Elastic waves were excited using a PZT sensor attached to one end of the bar, and the wave propagation was recorded in three ways: using a PZT sensor at the opposite end of the bar, using LDV at the opposite end, and on the sidewall. The research included samples of bars without anchorage, bars with anchorages (used for placement in a strength-testing machine), and specimens subjected to tensile testing (according to ISO 10406-1:2015). The collected signals were compared in both the time and frequency domains, considering variations in wave propagation due to different diameters, anchoring methods, and stress states. Based on the obtained results, it can be concluded that the analysis of the elastic wave propagation holds potential for assessing the condition of GFRP reinforcing bars.
Copyright (c) 2022 Anna RZEPKA, Dominika ZIAJA, Michał JUREK, Agnieszka WIATER https://creativecommons.org/licenses/by/4.0
Performance Evaluation of the Optimized Design Ratio Between the Diameters of the Basin and Curved Blade in the Gravitational Water Vortex Turbine
The key role of the gravitational water vortex turbine (GWVT) is to generate electricity to support modern civilization in their essential daily needs by harnessing kinetic energy from flowing water. With this, the lack of access to electricity can be addressed by utilizing the potential of the Philippines’ abundant bodies of water. This study evaluates the impact of low-density turbine blades on the GWVT with reference to the selected parameters: rotational speed and mechanical efficiency. The ANSYS simulation and laboratory test both found that the 0.55 ratio between the diameters of the nylon rod blade and the optimized basin with guide vanes achieved the highest rotational speed of 205.95 RPM and 120.1 RPM, respectively. Conversely, the design with a 0.60 ratio between the diameters of the steel blade and the normal basin provided optimum performance, achieving an average of 98.2 RPM and the highest mechanical efficiency of 43.75%, thereby preventing energy loss and maximizing output performance. Results also indicated a significant difference in the performance of the GWVT using the normal basin compared to the optimized basin with guide vanes. Lastly, there was a considerable difference in the performance of the GWVT for the design ratios of 0.55, 0.60, and 0.65 for the runner blade and basin, and further analysis showed that torque and rotational speed have a linear relationship. Thus, this study could serve as a benchmark for identifying alternative materials and optimizing the design of GWVT to help improve power generation using hydropower as a source of electricity.
Copyright (c) 2022 Christie Claire D. BOISER, Lance Arthur Lim CARPIO, Philip Jun S. CELERINOS, Joven Dy S. LEE, Gary G. PINILI https://creativecommons.org/licenses/by/4.0
Simulation of an Anti-Lock Braking System in a MATLAB/Simulink Environment for Various Road Adhesion Properties
Driving safety is very important to every vehicle user. Automobile manufacturers compete by introducing increasingly advanced safety systems, which, when combined with appropriate driver response, help prevent road accidents. The demand for such systems in vehicles has been driven mainly by the dynamic development of automotive industry and continually increasing number of vehicles on the road. This paper deals with safety systems that monitor wheel longitudinal slip, with emphasis on testing an anti-lock braking system (ABS) in a MATLAB/Simulink environment. The aim of the work is to describe the development and operation of ABS, electronic stability program (ESP), acceleration slip regulation (ASR) and electronic brakeforce distribution (EBD) systems, and to develop a simulation model of ABS. The relationship between the tire-to-road adhesion coefficient and longitudinal wheel slip was modeled using the Magic Formula equation. The contribution of this system to the vehicle’s braking process on various surfaces (dry asphalt, wet asphalt, snow, and ice) and at various initial velocities was analyzed. In particular, braking distance as a function of time comparing scenarios with ABS activated and deactivated is presented. The structure of the paper includes a theoretical part overviewing automotive safety systems, a description of the ABS model, and an analysis of the results.
Copyright (c) 2022 Łukasz KACPRZYCKI, Mateusz BRUKALSKI, Michał Mariusz ABRAMOWSKI, Hubert SAR, Piotr FUNDOWICZ https://creativecommons.org/licenses/by/4.0
The Effect of Vocal Effort on Voice Quality in Occupations with High Vocal Load
Phonation type identification and voice quality analysis are often performed using invasive methods such as laryngoscopy or fiberoscopy. This work aims to determine whether comparable results can be reproduced using acoustic analysis, a noninvasive method. The research consists of two series of experiments conducted on two separate groups of professional voice users to calculate the values of voice quality parameters (i.e., peak slope, normalized amplitude quotient, cepstral peak prominence, harmonics-to-noise ratio). The first experiment focused on recording voice in the sound studio (22 participants), while the second focused on collecting data using a dedicated mobile app outside the sound studio (20 participants). The collected samples were then analyzed to examine the effects of vocal load on voice quality and to determine variations between different groups of test participants. According to the results of the experiments, vocal load and working professionally with voice change the value of normalized amplitude quotient (NAQ). Furthermore, it has been shown that harmonics-to-noise ratio (HNR) and cepstral peak performance (CPP) vary with regular hydration status.
Copyright (c) 2022 Mateusz STERCZEWSKI, Daniel TRZASKOMA, Krzysztof SZKLANNY https://creativecommons.org/licenses/by/4.0
A Comprehensive Review on the Applications of Nanometal Additives in Fuels for Internal Combustion Engines
Nanometal additives have emerged as promising candidates for enhancing the performance and efficiency of internal combustion (IC) engines. The present review provides an overview of their applications and benefits in IC engines. These additives, characterized by their nanoscale size and unique properties, offer advantages such as improved combustion kinetics, enhanced catalytic activity, and reduced emissions. By leveraging their high surface-to-volume ratios and tailored surface chemistry, nanometal additives facilitate more efficient fuel combustion, leading to higher engine efficiency and lower pollutant emissions. Also, this review highlights the importance of nanometal additives in addressing challenges related to fuel quality, combustion efficiency, and environmental impact in IC engines, paving the way for cleaner and more efficient engine technologies.
Copyright (c) 2025 Udayakumar MOHAN, Selvaraju SIVAMANI https://creativecommons.org/licenses/by/4.0
Comparative Study of Matrix Methods for Modeling the Dispersive Character of Ultrasonic Guided Waves
This paper presents a comparative study of various matrix methods for obtaining the dispersion curves of ultrasonic guided waves in anisotropic media for both planar and cylindrical geometries. First, the mathematical formulation of the problem is introduced. Then, matrix methods are employed to generate the characteristic dispersion functions, with a particular focus on multilayer structures. To simplify the problem and enhance convergence, the formulation of Lamb modes is separated from that of shear modes. Dispersion curves are then plotted for single and multilayer planar and cylindrical geometries of propagating modes, with each case identifying the different modes obtained and explaining their symmetry characteristics. The dispersion curves are generated using a MATLAB program and compared with two software tools: Disperse Calculator for plates and GUIGUW for cylindrical structures. A perfect match is observed. A discussion is then presented to highlight the advantages and limitations of the matrix methods, offering reliable insights into which matrix method is most suitable for each type of waveguide and enabling the plotting of convergent curves with minimal computation time.
Copyright (c) 2025 Ismaine ZITOUNI, Hassan RHIMINI, Abdelkerim CHOUAF https://creativecommons.org/licenses/by/4.0
Strength Estimation of Teeth Reinforced with Different Types of Post Systems
Posts are permanent, single-tooth and periodontal restorations. During chewing, forces make teeth with posts to undergo complex stresses. The aim of this work is to compare and estimate the upper medial incisors restored with custom posts and prefabricated composite posts reinforced with fibreglass using the finite element method. Modelling and numerical analyses provide the opportunity to evaluate the reconstruction of teeth using custom and prefabricated posts.
Investigation of a Vibratory Stress Relief System for Hard-Turned EN 31 Components
This study examines the use of artificial neural networks (ANNs) to forecast and optimize residual stress and Brinell hardness in EN 31 components subjected to vibratory stress relief (VSR). The influence of important process parameters – amplitude, frequency, and time – was determined through comprehensive ANOVA analyses. According to the findings, residual stress and Brinell hardness are substantially influenced by amplitude, while frequency plays a crucial role in managing stress and hardness before VSR. The significance of time varied across different processes. The ANN model consistently demonstrated high predictive accuracy, achieving 99.82% for Brinell hardness after VSR, 98.27% for residual stress after VSR, 99.98% for Brinell hardness before VSR, and 98.20% for residual stress before VSR. Model performance was further improved through data transformation and normalization. A robust framework for optimizing VSR process parameters was established by integrating ANOVA and ANN, which enabled precise control over mechanical properties. This research emphasizes the potential of ANN in predictive modeling and process optimization in materials engineering, providing valuable insights for enhancing the performance and reliability of mechanical components through customized VSR processes.
Copyright (c) 2025 Pankaj BHOKARE, Vishal VASISTHA https://creativecommons.org/licenses/by/4.0
Modeling of the Acoustic Properties of Foamed Polypropylene Panels
This article presents research on modelling baffles with the desired properties of the sound absorption coefficient (SAC). The purpose of the study was to model and compare the SAC values based on selected theoretical models with the results obtained from measurements of this coefficient in panels made of foamed polypropylene. The assessment of sound absorption properties was carried out using two theoretical models: the Johnson–Champoux–Allard (JCA) model and the Sgard model. The accuracy of the calculated SAC was verified based on laboratory measurements of this parameter for selected material configurations, using the technique of two microphones in an impedance tube. Both theoretical and experimental studies were conducted on porous materials in the form of granules. The application of the Sgard model yielded the best results, with the smallest discrepancies in relation to the experimental tests. The results can be used to improve the SAC and efficiency of acoustic panels whose basic material is foamed polypropylene.
Investigating the Mechanical, Physical and Biological Properties of PMMA/TiO2 Composites with Nanoclay for Denture Applications
Prosthodontics uses permanent or removable dentures to replace missing teeth, with partial dentures made from cobalt chromium and full dentures from acrylic resin. This study presents Veracril self-curing acrylic, a material for hybrid artificial denture composites reinforced with montmorillonite (MMT) and titanium oxide (TiO2) particles. It is softer, lighter, and more stable than previous materials. Several experiments (mechanical, physical, and biological) have been carried out to examine the novel composite at various MMT and TiO2 weight ratios. The findings indicate that these additives significantly improve the mechanical properties of the matrix material, making it suitable for denture manufacturing. The addition of MMT as a filler enhances bonding between the matrix and additives. The additives' success in biological tests, including antibacterial activity and toxicity assessments, further supports their suitability for dental applications.
Enhancement of the Thermal Stability of Engine Block Alloy Al-10Si-1Cu-0.5Mg-0.5Ni-0.5Fe with Trace Additions of Ti and Zr
An investigation was carried out on the Al-10Si-1Cu-0.5Mg-0.5Ni-0.5Fe alloy engine block, emphasizing its physical and mechanical characteristics, as well as the presence of trace titanium (Ti) and zirconium (Zr). Three different alloys underwent processes such as homogenization, T6 solution treatment, quenching, and aging to observe both natural and artificial aging responses. The development of Al2Cu and Mg2Si phases within the aluminum matrix during the aging process led to the attainment of peak-aged strength. However, this strength diminished in the over-aged condition due to precipitation coarsening and recrystallization phenomena. The addition of Ti effectively refined the α-Al grain structure and led to the formation of thermally stable nano-sized Al3Ti dispersoids, which did not significantly enhance strength but prevented a drastic decline in the strength of the thermally damaged alloy. The simultaneous addition of Ti and Zr to the alloy further facilitated the precipitation of Al3(Ti, Zr) dispersoids, enhancing this capability. Trace addition reduced the alloys' toughness as well as thermal conductivity to a small extent due to grain refinement and precipitation formation, but these properties improved during aging due to recovery and recrystallization. Microstructural analysis of the alloys indicated that trace additions facilitated the formation of more finely distributed grains, contributing to grain refinement and preventing recrystallization in the over-aged state. The enhanced homogeneity of the grains due to trace additions was further supported by fractography studies.