Engineering Transactions
type: channel
description: Engineering Transactions (formerly Rozprawy Inżynierskie) is a refereed international journal founded in 1952. The journal promotes research and practice in engineering science and provides a forum for interdisciplinary publications combining mechanics with: Material science, Mechatronics, Biomechanics and Biotechnologies, Environmental science, Photonics, Information technologies, Other engineering applications. The journal publishes original papers covering a broad area of research activities including: Experimental and hybrid techniques, Analytical and numerical approaches. Review articles and special issues are also welcome. Following long tradition, all articles are peer reviewed and our expert referees ensure that the papers accepted for publication comply with high scientific standards. Engineering Transactions is a quarterly journal intended to be interesting and useful for the researchers and practitioners in academic and industrial communities. Occasionally, special issues of the journal may be devoted to publication of all or selected papers presented at international conferences or other scientific meetings. However, all papers intended for such an issue are subjected to the usual reviewing and acceptance procedure.
publisher: Institute of Fundamental Technological Research Polish Academy of Sciences
language: en
publication name: Engineering Transactions
issn: 0867-888X
copyright: Copyright on any open access article in the Engineering Transactions published by Polish Academy of Sciences and Institute of Fundamental Technological Research Polish Acoustical Society is retained by the author(s). Authors grant Institute of Fundamental Technological Research Polish Academy of Sciences a license to publish the article and identify itself as the original publisher. Authors also grant any user the right to use the article freely as long as its integrity is maintained and its original authors, citation details and publisher are identified. The Creative Commons Attribution License-ShareAlike 4.0 formalizes these and other terms and conditions of publishing articles. Exceptions to copyright policy For the articles which were previously published, before year 2019, policies that are different from the above. In all such, access to these articles is free from fees or any other access restrictions. Permissions for the use of the texts published in that journal may be sought directly from the Editorial Office of Engineering Transactions .
items: Collision Integral for Non-Equilibrium Distributions of 1D Bosons with Non-Linear Dispersions
items: Global buckling of a thin-walled T-frame with consideration of the shear effect
items: Analytical Approach and Shooting Method Solution of Nonlocal Eringen Elasticity Problem of Nanorods
items: Non-linear analysis of wrinkling phenomena in sandwich beams with soft core
items: Sustainable Natural and Synthetic fibers with Epoxy Composites of Mechanical Characterization and One-Way ANOVA Statistical Analysis
items: Preface
items: Simulation Study of Direct-Shear Test on FRP-to-Concrete Bonded Joints by Means of XFEM
items: Numerical modeling of aluminum alloy AW5083using large strain thermo-elasto-plasticity
items: Analysis of a Variable Geometry Radial Inflow Turbine Using 1D Mean-line Model
items: Blade prime-number / uniform angular distribution criterion for vibration reduction
items: Performance of a Hybrid Ichthyoid-Waterjet Articulated Propulsor
items: Analysis of the Braking Process for Curvilinear Motion of Vehicle
items: Energy Efficiency of an LPG-Powered Extended-Range Electric Vehicle
items: On Frequency Dependence of Stability in Materials With Fractional Viscosity
items: Determination of Operating Conditions of a Probe Block Designed for Fault Diagnostics in Rail Heads
items: The Development Features and Design of a Vibratory Gyroscope with a Metallic Cylindrical Resonator
items: Multi-Objective Optimization of Hobbing Process Parameters Based on Response Surface Method
items: Dynamic Eccentricity Modeling of a Switched Reluctance Motor
items: Simulation of Vibro-Isolation Performance For Sensitive Cargo Transportation on Planforms with Quasi-Zero Stiffness Suspension Under Impact Perturbations
items: Comparison of Gantry Drive and Crankset: A Pilot Study Across a Broad Power Spectrum
items: Prediction of Soil Liquefaction Using Machine Learning Approaches
items: Effect of Initial Scratch on Ship Bottom Plate Corrosion Rate and Structural Crashworthiness in Grounding Incidents
items: Multi-Objective Design of a Pneumatic Adaptive Impact Absorber
items: Characteristics Evaluation and Application of SBS Composite Modified bitumen Materials in Low Temperature Environment
items: Assessment of Methods for Determining Vehicle Emission Characteristics
items: The Development of Green Polylactic Acid (PLA)Composites for Wastewater Treatment – A Review
items: Research on Liquid Flow Resistance in Flow and Centrifugal Extraction Reactors
items: Effect of Turbulent Oil Film on the Dynamic Characteristics of 2-lobe Journal Bearings
items: Impact of Spin Slip Conditions on the Axisymmetric Rotation of a Spherical Particle in a Couple Stress Fluid Within a Cavity
items: Numerical and Experimental Analysis of Tuning Three Selected Types of Acoustic Helicoidal Resonators with 90-Degree Duct Elbow

Collision Integral for Non-Equilibrium Distributions of 1D Bosons with Non-Linear Dispersions
type: item
description: In order to understand transport phenomena in a quasi-classical regime the Boltzmann transport equation (BTE) is one of the most frequently used tools. Therein, the key quantity is a collision integral – the quantity that encapsulates the properties of the medium under consideration. Usually the result of this integral is approximated by one single parameter, the relaxation time. However it leaves one wondering if such situation is sufficient: for instance, if the dispersion of bosons is non-linear then what will be the influence of this non-linearity on the BTE. Here we give a fully analytic solution of the collisions’ integral for 1D bosonic gases with non-linear dispersion and far out of equilibrium. Our analytic result is given in terms of the Lerch transcendent function and it has been obtained for the case of two sub-systems (one dragging another), by taking a maximum-entropy displaced Bose–Einstein ansatz for their distributions. Currently, there are numerous experiments performed far away from equilibrium, where distributions are massively shifted and our result will serve as a main building block to derive distributions of bosons, and later linear and nonlinear transport coefficients, in such regimes.
subject: Research Papers
  topic: section
subject: Boltzmann transport equation
  topic: keywords
subject: bosons with non-linear dispersion
  topic: keywords
subject: non-equilibrium distributions
  topic: keywords
creator: Piotr Chudzinski
creator: Wieslaw Larecki
rights: Copyright (c) 2025 Piotr Chudzinski, Wieslaw Larecki https://creativecommons.org/licenses/by/4.0
date: 2025-12-12
publication date: 2025-12-12
doi: 10.24423/engtrans.2025.3692

Global buckling of a thin-walled T-frame with consideration of the shear effect
type: item
description: The work concerns the global elastic buckling problem of a thin-walled T-frame with consideration of the shear effect. A novel approach was used to account for this effect namely the non-linear shear deformation theory which gives as a result the shear deformation function describing the behaviour of the beam cross-section. This thin-walled T-frame consists of horizontal beam and vertical column made of the same standard H-beams. The shape of this standard H-beam and the dimensionless deformation function of the plane cross-section, being the result of the shear effect, are analytical described. The buckling problem of the frame is analytically formulated and solved. The critical loads of exemplary beams are analytically determined. Moreover, a numerical FEM model of the frame is elaborated and the critical loads of exemplary frames are determined. Consequently, the research results obtained by both methods are compared and the advantages of the proposed approach is discussed.
subject: Research Papers
  topic: section
subject: elastic buckling
  topic: keywords
subject: frame
  topic: keywords
subject: H-beam
  topic: keywords
subject: thin-walled beam
  topic: keywords
subject: shear effect
  topic: keywords
creator: Krzysztof Magnucki
creator: Paweł Jasion
rights: Copyright (c) 2025 Krzysztof Magnucki, Paweł Jasion https://creativecommons.org/licenses/by/4.0
date: 2026-01-14
publication date: 2026-01-14
doi: 10.24423/engtrans.2026.3641

Analytical Approach and Shooting Method Solution of Nonlocal Eringen Elasticity Problem of Nanorods
type: item
description: The aim of this paper is to study the postbuckling behaviors of the nanorods combined with the small scale effects. In this paper, buckling of a nanorod column subjected to tip load is investigated. The nanorod is on a clamped support at one end, while the other end is simply-supported subjected to axial compression. At this end, the nanorod is movable only in a horizontal direction. The governing differential equation describing the behavior of the nanorod is developed by the moment–curvature relationship in analogy with the classical Euler–Bernoulli beam theory together with the equilibrium equations, including the effects of nonlocal elasticity as well as corresponding boundary conditions. The numerical shooting methods are derived and employed to solve the differential equations in this problem. The results, including nonlocal elasticity, reveal that nanorods have decreased structural stiffness and show the significant effect of geometrical parameters on the stability of buckled nanorods, emphasizing the importance of accounting for their interaction in the design of nanostructural systems.
subject: Technical Notes
  topic: section
subject: nonlocal elasticity theory
  topic: keywords
subject: nanorods
  topic: keywords
subject: small-scale effect
  topic: keywords
subject: postbuckling behaviors
  topic: keywords
creator: Aleksandra Manecka-Padaż
creator: Ewa Eliza Rożko
creator: Zdzisław Nowak
creator: Piotr Chudzinski
rights: Copyright (c) 2025 Aleksandra Manecka-Padaż, Ewa Eliza Rożko, Zdzisław Nowak , Piotr Chudzinski https://creativecommons.org/licenses/by/4.0
date: 2025-12-12
publication date: 2025-12-12
doi: 10.24423/engtrans.2025.3681

Non-linear analysis of wrinkling phenomena in sandwich beams with soft core
type: item
description: The work is devoted to the local stability analysis of sandwich beams with light core. A linear as well as non-linear numerical analysis is carried out with the use of the finite element method (FEM). Both material and geometrical nonlinearities are taken into account. The goal of the investigation is to examine the influence of the material model on the post-buckling behaviour of a sandwich beam especially on the formation and developing of wrinkles on the compressed face. A pure bending condition is considered for the beam simply supported at both ends. The results for materials of theoretical properties are presented as well as for data from experiments on aluminium sandwich beams. From the results it is seen that the linear analysis of wrinkling phenomenon for non-linear materials gives overestimated results and does not predict correctly the buckling shape.
subject: Research Papers
  topic: section
subject: wrinkling
  topic: keywords
subject: sandwich beams
  topic: keywords
subject: bending
  topic: keywords
subject: buckling
  topic: keywords
subject: equilibrium path
  topic: keywords
subject: non-linear analysis
  topic: keywords
creator: Paweł Jasion
creator: Iwona Małgorzata Wstawska
creator: Kamil Kołodziński
rights: Copyright (c) 2025 Paweł Jasion, Iwona Małgorzata Wstawska, Kamil Kołodziński https://creativecommons.org/licenses/by/4.0
date: 2025-12-11
publication date: 2025-12-11
doi: 10.24423/engtrans.2025.3607

Sustainable Natural and Synthetic fibers with Epoxy Composites of Mechanical Characterization and One-Way ANOVA Statistical Analysis
type: item
description: It is now well recognized that the combination of natural and synthetic fibers in synergistic fiber composite materials can greatly broaden their applications in engineering and technology. Natural-fibers are gaining more consciousness because of their biodegradability, easy availability, durability, and resistance to corrosion, positioning them as an eco-friendly substitute for conventional materials. At the same time, fiber-reinforced composites are increasingly replacing metals in multiple sectors owing to their cost-effectiveness and energy efficiency. Epoxy resin-based hybrid composites were prepared by incorporating glass, hemp and ramie fibers through the hand layup approch. Laminates were characterized for tensile, flexural, impact, and hardness performance using ASTM standard methods. The greatest tensile strength, 73.10 MPa, was achieved in the glass/ramie fiber composite. The hybrid composites comprising glass, ramie, and hemp fibers exhibited enhanced flexural behavior of 18.22 MPa, impact resistance of 142.45 kJ/m². Among the tested configurations, the glass–ramie fiber composite recorded the highest hardness value of 27.73 HV. Overall, the determination highlight that glass-ramie-hemp fiber-mixed epoxy composite materials can serve as prospective eco-friendly substitute to conventional synthetic composites in non-structural applications, such as automotive interiors, by offering a balance of good mechanical performance and sustainability.
subject: Research Papers
  topic: section
subject: Hybrid Composite
  topic: keywords
subject: Natural and Synthetic fibers
  topic: keywords
subject: Mechanical Properties
  topic: keywords
subject: Glass
  topic: keywords
subject: Ramie
  topic: keywords
subject: Hemp
  topic: keywords
subject: Hand lay-up method
  topic: keywords
creator: Sadashiva Kemparaju
creator: Bhanu Prathap Rangaswamy
creator: Balaji Javaraiah
creator: Shwetha Mahadev
creator: Rathika Murugan
creator: Tarakeshwar Jane
rights: Copyright (c) 2025 Sadashiva Kemparaju, Bhanu Prathap Rangaswamy, Balaji Javaraiah, Shwetha Mahadev, Rathika Murugan, Tarakeshwar Jane https://creativecommons.org/licenses/by/4.0
date: 2025-12-18
publication date: 2025-12-18
doi: 10.24423/engtrans.2025.3665

Preface
type: item
description: 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.
subject: SIMRTRANS: Innovative solutions in means of transport
  topic: section
creator: Dariusz WIĘCKOWSKI
rights: Copyright (c) 2025 Dariusz WIĘCKOWSKI https://creativecommons.org/licenses/by/4.0
date: 2025-09-24
publication date: 2025-09-24
starting page: 325
ending page: 325
doi: 10.24423/engtrans.3603.2025

Simulation Study of Direct-Shear Test on FRP-to-Concrete Bonded Joints by Means of XFEM
type: item
description: A proper numerical modelling of FRP-to-concrete bonded joints is crucial for determining their strength. In this paper the results of numerical analyses performed by XFEM on such joints in direct-shear test are presented. The study uses a fracture mechanics approach based on the traction-separation law for definition the FRP-concrete interface. It includes definition of damage initiation as well as damage evolution, taking advantage of the fracture energy for plain concrete as well as the interfacial fracture energy of analysed joint. The interfacial fracture energy of bonded joint is essential for accurately describing the local bond–slip behaviour. The numerical study is aimed to investigate the sensitivity of direct-shear test models to magnitude of fracture energies, material strengths, type of adhesive and the length of FRP-to-concrete joint. Some general results and conclusions of performed analyses are presented.
subject: Research Papers
  topic: section
subject: FRP strengthening
  topic: keywords
subject: XFEM analysis
  topic: keywords
subject: modes of fracture energy
  topic: keywords
subject: FRP-to-concrete joints
  topic: keywords
subject: interfacial fracture energy
  topic: keywords
subject: traction-separation law
  topic: keywords
creator: Iwona Jankowiak
rights: Copyright (c) 2025 Iwona Jankowiak https://creativecommons.org/licenses/by/4.0
date: 2025-12-12
publication date: 2025-12-12
doi: 10.24423/engtrans.2025.3626

Numerical modeling of aluminum alloy AW5083using large strain thermo-elasto-plasticity
type: item
description: This paper deals with the constitutive modeling and finite element simulations of advanced models related to large strain thermo-elasto-plastic behavior of aluminum alloy AW5083, which can reproduce the material response at different temperatures from room temperature up to 500 degrees Celsius. Significant focus is placed on the internal sources of cooling and heating resulting from thermo-elastic and thermo-plastic couplings, respectively, and the influence of elevated temperature on couplings. The formulation of the constitutive description is based on the thermodynamic approach. Two models are presented and tested: including temperature-dependent and temperature-independent plastic free energy function. Numerical tests of the developed models are carried out for a uniaxial tension test. For the sake of comparison with experimental results, a dogbone specimen examined in a tensile machine is analyzed.
subject: Research Papers
  topic: section
subject: aluminum alloy AW5083
  topic: keywords
subject: thermo-elasto-plasticity
  topic: keywords
subject: temperature dependent parameters
  topic: keywords
subject: large strains
  topic: keywords
subject: finite element method
  topic: keywords
creator: Agnieszka Sobierańska
creator: Balbina Wcisło
rights: Copyright (c) 2025 Agnieszka Sobierańska, Balbina Wcisło https://creativecommons.org/licenses/by/4.0
date: 2025-12-18
publication date: 2025-12-18
doi: 10.24423/engtrans.2025.3639

Analysis of a Variable Geometry Radial Inflow Turbine Using 1D Mean-line Model
type: item
description: 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.
subject: SIMRTRANS: Innovative solutions in means of transport
  topic: section
subject: mathematical modelling
  topic: keywords
subject: radial inflow turbine
  topic: keywords
subject: variable geometry
  topic: keywords
subject: loss analysis
  topic: keywords
creator: Dmytro SAMOILENKO
rights: Copyright (c) 2025 Dmytro SAMOILENKO https://creativecommons.org/licenses/by/4.0
date: 2025-09-24
publication date: 2025-09-24
starting page: 463
ending page: 483
doi: 10.24423/engtrans.3498.2025

Blade prime-number / uniform angular distribution criterion for vibration reduction
type: item
description: Currently, the vibration noise of casting cleaning equipment exceeds 95 dB, which not only impacts the equipment's service life but also jeopardizes workers' health. The primary cause lies in the resonance tendency resulting from an uneven distribution of blades in the shot blasting device. The prime-number / uniform angular distribution criterion and the dynamic balance elimination relation are established in this paper, aiming to minimize resonance coupling while considering the internal characteristics of the shot blast device and blade assembly. Subsequently, the shot blasting device of seven prime-number angular front-curved blades was designed and established, and the dynamic balance caused by uneven blade distribution was offset by drilling. We employ discrete element method analysis to evaluate projectile velocity and stability. Results indicate that shot velocity reaches a maximum of 75 m/s with fluctuations within 4 m/s. After reaching 0.24 s, particles accelerated by the shot blasting device achieve relative stability. Finally, vibration data acquisition at a sampling frequency of 10 Ksps demonstrates that noise levels are reduced from 97 dB (traditional structure) to 93.3 dB (new model). This new criterion for shot blasting machine models mitigates vibrations during operation while enhancing working conditions and improving overall stability and reliability.
subject: Research Papers
  topic: section
subject: shot blasting machine
  topic: keywords
subject: vibration-induced noise
  topic: keywords
subject: structural optimization
  topic: keywords
subject: co-prime / uniform vibration reduction selection criteria
  topic: keywords
subject: shot blasting device of 7 co-prime front curved blades
  topic: keywords
creator: Yong Li
creator: Yaao Di
creator: Wenzheng Dong
creator: Fangxiang Yin
creator: Yihao Yin
creator: Shanling Han
rights: Copyright (c) 2025 Yong Li, Yaao Di, Wenzheng Dong, Fangxiang Yin, Yihao Yin, Shanling Han https://creativecommons.org/licenses/by/4.0
date: 2025-12-11
publication date: 2025-12-11
doi: 10.24423/engtrans.2025.3603

Performance of a Hybrid Ichthyoid-Waterjet Articulated Propulsor
type: item
description: 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.
subject: Research Papers
  topic: section
subject: autonomous underwater vehicle
  topic: keywords
subject: waterjet propulsion
  topic: keywords
subject: fish swimming
  topic: keywords
subject: flutter
  topic: keywords
subject: fluid-conveying pipe
  topic: keywords
creator: Tomasz SZMIDT
rights: Copyright (c) 2025 Tomasz SZMIDT https://creativecommons.org/licenses/by/4.0
date: 2025-12-17
publication date: 2025-12-17
starting page: 591
ending page: 615
doi: 10.24423/engtrans.3593.2025

Analysis of the Braking Process for Curvilinear Motion of Vehicle
type: item
description: 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 a…
subject: Research Papers
  topic: section
subject: active safety
  topic: keywords
subject: braking on the road arc
  topic: keywords
subject: braking force
  topic: keywords
subject: driver reaction time
  topic: keywords
subject: intensity of turning
  topic: keywords
creator: Piotr FUNDOWICZ
creator: Hubert SAR
creator: Mateusz BRUKALSKI
creator: Michał ABRAMOWSKI
rights: Copyright (c) 2025 Piotr FUNDOWICZ, Hubert SAR, Mateusz BRUKALSKI, Michał ABRAMOWSKI https://creativecommons.org/licenses/by/4.0
date: 2025-12-17
publication date: 2025-12-17
starting page: 617
ending page: 633
doi: 10.24423/engtrans.3489.2025

Energy Efficiency of an LPG-Powered Extended-Range Electric Vehicle
type: item
description: 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.
subject: SIMRTRANS: Innovative solutions in means of transport
  topic: section
subject: extended-range electric vehicle
  topic: keywords
subject: efficiency
  topic: keywords
subject: energy consumption
  topic: keywords
subject: LPG
  topic: keywords
creator: Paweł KRAWCZYK
creator: Artur KOPCZYŃSKI
creator: Jakub LASOCKI
rights: Copyright (c) 2025 Paweł KRAWCZYK, Artur KOPCZYŃSKI, Jakub LASOCKI https://creativecommons.org/licenses/by/4.0
date: 2025-09-24
publication date: 2025-09-24
starting page: 421
ending page: 440
doi: 10.24423/engtrans.3490.2025

On Frequency Dependence of Stability in Materials With Fractional Viscosity
type: item
description: Material instability refers to the tendency of materials to undergo alterations in its properties in loading. The concept of instability is governed by the constitutive equation of solids. Our analysis uses the entire set of equations describing the motion of solids by adding the kinematical equation and Cauchy’s equations of motion. Damping or rate-dependence plays a crucial role in stability. A potential generalization involves the utilization of fractional order derivatives of strain or stress tensors. The stability analysis primarily focuses on periodic perturbations. The way of the loss of stability on various parts of the stability boundary is under consideration.
subject: SolMech 2024
  topic: section
subject: applied fractional calculus
  topic: keywords
subject: material instability
  topic: keywords
subject: dynamical systems
  topic: keywords
creator: Peter B. Béda
rights: Copyright (c) 2025 Peter B. Béda https://creativecommons.org/licenses/by/4.0
date: 2025-12-12
publication date: 2025-12-12
doi: 10.24423/engtrans.2025.3495

Determination of Operating Conditions of a Probe Block Designed for Fault Diagnostics in Rail Heads
type: item
description: 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.
subject: Research Papers
  topic: section
subject: railway rails diagnostics
  topic: keywords
subject: ultrasonic examination
  topic: keywords
subject: ultrasonic probe-rail interface
  topic: keywords
creator: Zbigniew RANACHOWSKI
creator: Sławomir MACKIEWICZ
creator: Tomasz KATZ
creator: Tomasz DĘBOWSKI
creator: Grzegorz STARZYŃSKI
creator: Marcin LEWANDOWSKI
creator: Łukasz ANTOLIK
rights: Copyright (c) 2025 Zbigniew RANACHOWSKI, Sławomir MACKIEWICZ, Tomasz KATZ, Tomasz DĘBOWSKI, Grzegorz STARZYŃSKI, Marcin LEWANDOWSKI, Łukasz ANTOLIK https://creativecommons.org/licenses/by/4.0
date: 2025-12-17
publication date: 2025-12-17
starting page: 579
ending page: 590
doi: 10.24423/engtrans.3522.2025

The Development Features and Design of a Vibratory Gyroscope with a Metallic Cylindrical Resonator
type: item
description: 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.
subject: Research Papers
  topic: section
subject: vibratory gyroscope
  topic: keywords
subject: standing wave
  topic: keywords
subject: control system
  topic: keywords
subject: auto-compensation
  topic: keywords
creator: Valerii CHIKOVANI
creator: Serhii HOLOVACH
creator: Hryhorii STROKACH
creator: Vadym AVRUTOV
rights: Copyright (c) 2025 Valerii CHIKOVANI, Serhii HOLOVACH, Hryhorii STROKACH, Vadym AVRUTOV https://creativecommons.org/licenses/by/4.0
date: 2025-06-26
publication date: 2025-06-26
starting page: 279
ending page: 304
doi: 10.24423/engtrans.3458.2025

Multi-Objective Optimization of Hobbing Process Parameters Based on Response Surface Method
type: item
description: In hobbing machining, gear geometric accuracy is an important factor affecting gear working performance, which is determined by the interaction of different process parameters. To improve the geometric accuracy of hobbing surface and obtain the minimum geometric error, this paper adopts the response surface method (RSM) to study the effects of various technological parameters on the geometric accuracy, and explores the influence law of various factors on the geometric accuracy through the response surface diagram. The mathematical models of total profile deviation, total helix deviation, cumulative total deviation of tooth spacing and radial runout were established based on response surface method, and the reliability of the models was tested by variance analysis. Non-dominated sorting whale optimization algorithm (NSWOA) was used to solve the mathematical model, and Pareto solution set was obtained. Entropy weight-TOPSIS method was used to determine the optimal scheme after NSWOA algorithm optimization. After optimization, the total deviation of tooth profile is reduced by 8.04 %, the total deviation of helix is reduced by 9.17 %, the cumulative total deviation of tooth spacing is reduced by 3.88 %, and the radial runout is reduced by 7.45 %, which proves that the optimized scheme can improve the gear accuracy after hobbing machining, and provides a reference for the reasonable selection of gear hobbing process parameters.
subject: Research Papers
  topic: section
subject: hobbing machining
  topic: keywords
subject: response surface method
  topic: keywords
subject: multi-objective optimization
  topic: keywords
subject: geometric accuracy
  topic: keywords
creator: Yazhou Wang
creator: Xiaohui Yin
rights: Copyright (c) 2025 Yazhou Wang, Xiaohui Yin https://creativecommons.org/licenses/by/4.0
date: 2025-12-12
publication date: 2025-12-12
doi: 10.24423/engtrans.2025.3453

Dynamic Eccentricity Modeling of a Switched Reluctance Motor
type: item
description: 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.
subject: SIMRTRANS: Innovative solutions in means of transport
  topic: section
subject: switched reluctance motor
  topic: keywords
subject: SRM
  topic: keywords
subject: motor diagnostics
  topic: keywords
subject: eccentricity
  topic: keywords
creator: Jakub LORENCKI
creator: Adrian CHMIELEWSKI
rights: Copyright (c) 2025 Jakub LORENCKI, Adrian CHMIELEWSKI https://creativecommons.org/licenses/by/4.0
date: 2025-09-24
publication date: 2025-09-24
starting page: 441
ending page: 461
doi: 10.24423/engtrans.3518.2025

Simulation of Vibro-Isolation Performance For Sensitive Cargo Transportation on Planforms with Quasi-Zero Stiffness Suspension Under Impact Perturbations
type: item
description: This work deals with the theoretical modeling of the vertical dynamics of a specialized vehicle featuring a dual suspension system. Vehicle ride quality is essential for ensuring the safety and comfort of passengers and the protection of sensitive or hazardous cargo. The study focuses on a two-axle vehicle model with a dual suspension system. The first level comprises a traditional suspension with linear stiffness, while the second level features nonlinear quasi-zero stiffness (QZS) characteristics. The research employs a discrete nonlinear dynamic model considers the vertical displacements and angular rotations of the vehicle’s masses. The nonlinear QZS response is modeled to optimize vibration isolation performance under varying load conditions, while damping effects are included via a Rayleigh dissipation function. The integral characteristics of the QZS element are also studied in detail using finite element (FE) computer simulations in a 3D statement. These simulations provide a comprehensive understanding of the mechanical response and stress-strain distribution within the QZS element, validating its performance under real-world conditions. The results demonstrate the influence of the nonlinear suspension characteristics on the vibration isolation performance and load stability. The QZS-based suspension effectively reduces dynamic stresses, particularly under low-frequency excitations, while maintaining structural integrity and operational efficiency.
subject: SIMRTRANS: Innovative solutions in means of transport
  topic: section
subject: vibro-isolation performance
  topic: keywords
subject: nonlinear discrete model
  topic: keywords
subject: kinematic excitations
  topic: keywords
subject: quasi-zero stiffness
  topic: keywords
subject: meta-structures
  topic: keywords
creator: Oleksiy Larin
creator: Ksenia Potopalska
creator: Galina Timchenko
creator: Nikita Vasylchenko
rights: Copyright (c) 2025 Oleksiy Larin, Ksenia Potopalska, Galina Timchenko, Nikita Vasylchenko https://creativecommons.org/licenses/by/4.0
date: 2025-12-16
publication date: 2025-12-16
doi: 10.24423/engtrans.2025.3484

Comparison of Gantry Drive and Crankset: A Pilot Study Across a Broad Power Spectrum
type: item
description: 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.
subject: SolMech 2024
  topic: section
subject: gantry
  topic: keywords
subject: crankset
  topic: keywords
subject: drive
  topic: keywords
subject: power
  topic: keywords
subject: vehicle
  topic: keywords
creator: Łukasz BEREŚ
creator: Marcin OBSZAŃSKI
creator: Paweł PYRZANOWSKI
rights: Copyright (c) 2025 Łukasz BEREŚ, Marcin OBSZAŃSKI, Paweł PYRZANOWSKI https://creativecommons.org/licenses/by/4.0
date: 2025-12-17
publication date: 2025-12-17
starting page: 659
ending page: 685
doi: 10.24423/engtrans.3485.2025

Prediction of Soil Liquefaction Using Machine Learning Approaches
type: item
description: 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.
subject: Research Papers
  topic: section
subject: liquefaction
  topic: keywords
subject: support vector machine
  topic: keywords
subject: mathematical functions
  topic: keywords
subject: divisional approaches
  topic: keywords
subject: performance metricsfunctions
  topic: keywords
subject: performance metrics
  topic: keywords
creator: Md. Mahabub RAHMAN
creator: Md. Belal HOSSAIN
creator: Abu SAYED
rights: Copyright (c) 2025 Md. Mahabub RAHMAN, Md. Belal HOSSAIN, Abu SAYED https://creativecommons.org/licenses/by/4.0
date: 2025-06-26
publication date: 2025-06-26
starting page: 257
ending page: 277
doi: 10.24423/engtrans.3360.2025

Effect of Initial Scratch on Ship Bottom Plate Corrosion Rate and Structural Crashworthiness in Grounding Incidents
type: item
description: 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.
subject: Research Papers
  topic: section
subject: scratch
  topic: keywords
subject: ship grounding
  topic: keywords
subject: severe corrosion
  topic: keywords
subject: finite element analysis
  topic: keywords
creator: Ocid MURSID
creator: Dean Nadhif ALFARIS
creator: Tuswan TUSWAN
creator: Ahmad Fauzan ZAKKI
creator: Aulia WINDYANDARI
creator: Karno R. MALAU
creator: Haris NUBLI
rights: 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
date: 2025-06-26
publication date: 2025-06-26
starting page: 233
ending page: 256
doi: 10.24423/engtrans.3434.2025

Multi-Objective Design of a Pneumatic Adaptive Impact Absorber
type: item
description: 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.
subject: Research Papers
  topic: section
subject: adaptive pneumatic absorbers
  topic: keywords
subject: impact absorption
  topic: keywords
subject: design optimization
  topic: keywords
subject: multi-objective optimization
  topic: keywords
subject: mass flow rate
  topic: keywords
creator: Rafal WISZOWATY
creator: Cezary GRACZYKOWSKI
creator: Grzegorz MIKUŁOWSKI
creator: Jan HOLNICKI-SZULC
creator: Zbigniew WOŁEJSZA
creator: Anita ORŁOWSKA-GAŁĘZIA
creator: Łukasz JANKOWSKI
rights: 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
date: 2025-12-17
publication date: 2025-12-17
starting page: 555
ending page: 578
doi: 10.24423/engtrans.3546.2025

Characteristics Evaluation and Application of SBS Composite Modified bitumen Materials in Low Temperature Environment
type: item
description: To improve the resistance of asphalt pavement to low temperature cracking, the study proposes a composite modified asphalt based on styrene butadiene styrene copolymer and rubber crumb. It is also tested for its performance in low temperature environment. The test results indicated that although after aging and freeze-thaw cycles, the creep rate of both modified asphalt and styrene butadiene styrene copolymer/rubber crumb were reduced. However, the creep rate of styrene butadiene styrene copolymer/rubber crumb composite modified asphalt was always better than that of styrene butadiene styrene copolymer modified asphalt. As an example, the creep rate of aged asphalt was 0.37 and 0.44 at -12°C, respectively. When asphalt mixes underwent freeze-thaw cycles and age, their fracture energy densities all drastically decreased. The fracture energy density of styrene butadiene styrene copolymer/rubber crumb composite modified asphalt mixtures, on the other hand, was larger than that of styrene butadiene styrene copolymer modified asphalt mixtures. The above results indicate that the composite modified asphalt with styrene butadiene styrene copolymer/rubber crumb has good rheological ability and freeze-thaw resistance, which can effectively ensure the low temperature performance of asphalt pavement.
subject: Research Papers
  topic: section
subject: SBS
  topic: keywords
subject: modified bitumen
  topic: keywords
subject: rheological properties
  topic: keywords
subject: low temperature properties
  topic: keywords
subject: cyclic freezing and thawing
  topic: keywords
subject: crumb rubber
  topic: keywords
creator: Wenxiao Ren
creator: Ping Li
rights: Copyright (c) 2025 Wenxiao Ren, Ping Li https://creativecommons.org/licenses/by/4.0
date: 2025-12-18
publication date: 2025-12-18
doi: 10.24423/engtrans.2025.3561

Assessment of Methods for Determining Vehicle Emission Characteristics
type: item
description: 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.
subject: SIMRTRANS: Innovative solutions in means of transport
  topic: section
subject: pollutant emissions
  topic: keywords
subject: emission modeling
  topic: keywords
subject: road emissions
  topic: keywords
subject: parametric estimation
  topic: keywords
creator: Piotr LASKOWSKI
creator: Edward KOZŁOWSKI
creator: Magdalena ZIMAKOWSKA-LASKOWSKA
creator: Piotr WIŚNIOWSKI
rights: Copyright (c) 2025 Piotr LASKOWSKI, Edward KOZŁOWSKI, Magdalena ZIMAKOWSKA-LASKOWSKA, Piotr WIŚNIOWSKI https://creativecommons.org/licenses/by/4.0
date: 2025-09-24
publication date: 2025-09-24
starting page: 407
ending page: 420
doi: 10.24423/engtrans.3494.2025

The Development of Green Polylactic Acid (PLA)Composites for Wastewater Treatment – A Review
type: item
description: 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.
subject: Review Papers
  topic: section
subject: polylactic acid
  topic: keywords
subject: PLA
  topic: keywords
subject: wastewater treatment
  topic: keywords
subject: adsorbents
  topic: keywords
subject: adsorption
  topic: keywords
subject: PLA composites
  topic: keywords
subject: environmental sustainability
  topic: keywords
creator: Andriy Anta KACARIBU
creator: Yuliani AISYAH
creator: Febriani FEBRIANI
creator: Darwin DARWIN
rights: Copyright (c) 2022 Andriy Anta KACARIBU, Yuliani AISYAH, Febriani FEBRIANI, Darwin DARWIN https://creativecommons.org/licenses/by/4.0
date: 2025-09-24
publication date: 2025-09-24
starting page: 485
ending page: 524
doi: 10.24423/engtrans.3534.2025

Research on Liquid Flow Resistance in Flow and Centrifugal Extraction Reactors
type: item
description: 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.
subject: SIMRTRANS: Innovative solutions in means of transport
  topic: section
subject: extraction reactor
  topic: keywords
subject: numerical investigations
  topic: keywords
subject: flow resistance
  topic: keywords
subject: medicinal herbs
  topic: keywords
creator: Jędrzej MĄCZAK
creator: Dmytro SAMOILENKO
creator: Michal MAKOWSKI
creator: Lech KNAP
rights: Copyright (c) 2025 Jędrzej MĄCZAK, Dmytro SAMOILENKO, Michal MAKOWSKI, Lech KNAP https://creativecommons.org/licenses/by/4.0
date: 2025-09-24
publication date: 2025-09-24
starting page: 387
ending page: 405
doi: 10.24423/engtrans.3471.2025

Effect of Turbulent Oil Film on the Dynamic Characteristics of 2-lobe Journal Bearings
type: item
description: 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.
subject: Research Papers
  topic: section
subject: multilobe journal bearing
  topic: keywords
subject: turbulent oil film
  topic: keywords
subject: dynamic characteristics
  topic: keywords
subject: rotor stability
  topic: keywords
creator: Stanislaw Kazimierz STRZELECKI
rights: Copyright (c) 2025 Stanislaw Kazimierz STRZELECKI https://creativecommons.org/licenses/by/4.0
date: 2025-06-26
publication date: 2025-06-26
starting page: 219
ending page: 232
doi: 10.24423/engtrans.3475.2025

Impact of Spin Slip Conditions on the Axisymmetric Rotation of a Spherical Particle in a Couple Stress Fluid Within a Cavity
type: item
description: 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.
subject: Research Papers
  topic: section
subject: couple stress fluid
  topic: keywords
subject: spin slip effect
  topic: keywords
subject: rotation
  topic: keywords
subject: torque
  topic: keywords
subject: spherical particle
  topic: keywords
creator: Shekhar NISHAD
creator: Krishna Prasad MADASU
rights: Copyright (c) 2025 Shekhar NISHAD, Krishna Prasad MADASU https://creativecommons.org/licenses/by/4.0
date: 2025-06-26
publication date: 2025-06-26
starting page: 199
ending page: 218
doi: 10.24423/engtrans.3427.2025

Numerical and Experimental Analysis of Tuning Three Selected Types of Acoustic Helicoidal Resonators with 90-Degree Duct Elbow
type: item
description: 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.
subject: OSA 2024
  topic: section
subject: helicoidal resonator
  topic: keywords
subject: duct acoustics
  topic: keywords
subject: experiment
  topic: keywords
subject: numerical analysis
  topic: keywords
creator: Wojciech ŁAPKA
rights: Copyright (c) 2025 Wojciech ŁAPKA https://creativecommons.org/licenses/by/4.0
date: 2025-12-17
publication date: 2025-12-17
starting page: 701
ending page: 717
doi: 10.24423/engtrans.3377.2025