Nauki Techniczne

Bulletin of the Polish Academy of Sciences Technical Sciences

Opis

The Bulletin of the Polish Academy of Sciences Technical Sciences is published bimonthly by the Division IV Engineering Sciences of the Polish Academy of Sciences, since the beginning of the existence of the PAS in 1952. The journal is peer‐reviewed and is published both in printed and electronic form. It is established for the publication of original high quality papers from multidisciplinary Engineering sciences with the following topics preferred:

Artificial and Computational Intelligence,
Biomedical Engineering and Biotechnology,
Civil Engineering,
Control, Informatics and Robotics,

Electronics, Telecommunication and Optoelectronics,
Mechanical and Aeronautical Engineering, Thermodynamics,
Material Science and Nanotechnology,
Power Systems and Power Electronics.

Submit your article

Journal Metrics:

JCR Impact Factor 2023:	1.2
5 Year Impact Factor 2022:	1.1
CiteScore 2023:	2.8
SCImago Journal Rank (SJR) 2023:	0.282
Source Normalized Impact per Paper (SNIP) 2023:	0.573
Ministry of Education and Science:	100 points

Abbreviated title: Bull. Pol. Acad. Sci. Tech. Sci.

ISSN

ISSN 2300-1917

Editorial Board 2023-2025

Editor-in-Chief:

A. Rogalski, Military University of Technology

Honorary (Past) Editor-in Chief:

T. Kaczorek, Warsaw University of Technology

M.P. Kaźmierkowski, Warsaw University of Technology

Deputy Editor-in-Chief:

B. Błachowski, Institute of Fundamental Technological Research PAN

M. Mrozowski, Gdansk University of Technology

Board of Topical Co-editors:

Artificial and Computational Intelligence

S. Osowski, B. Sawicki and T. Leś, Warsaw University of Technology

Biomedical Engineering and Biotechnology

D. Pijanowska, Institute of Biocybernetics and Biomedical Engineering PAN

Civil Engineering

L. Czarnecki, Building Research Institute, ITB, Warsaw

Ł. Sadowski, Wroclaw University of Science and Technology

Control, Robotics and Informatics

J. Klamka and A. Babiarz, Silesian Technical University

J. Stefanowski, Poznan University of Technology

Electronics, Telecommunication and Optoelectronics

M. Mrozowski and A. Lamęcki, Gdansk University of Technology

Mechanical and Aeronautical Engineering, Thermodynamics

B. Błachowski, Institute of Fundamental Technological Research PAN

G. Zboiński, Institute of Fluid-Flow Machinery PAN and University of Warmia and Mazury in Olsztyn

Materials Science and Nanotechnology

B. Major and P. Czaja, Institute of Metallurgy and Materials Science PAN

Power Systems and Power Electronics

J. Rąbkowski and M. Jasiński, Warsaw University of Technology

International Editorial Advisory Board

R. Asthana, University of Wisconsin-Stout, Menomonie, USA

Xu Binshi, China Association of Plant Engineering, Beijing, P.R. China

F. Blaabjerg, Aalborg University, Denmark

C. Cecati, University of L’Aquila, Italy

A. Cichocki, RIKEN Institute, Tokyo, Japan

M. David, National Polytechnique de Toulouse, France

R. Ebner, Materials Centre Leoben, Leoben, Austria

E. Fornasini, University of Padova, Padova, Italy

L.G. Franquelo, University of Sevilla, Spain

M. Gad-el-Hak, Virginia Commonwealth University, Richmond, USA

M. Giersig, Free University of Berlin, Germany

D. van Gemert, Catholic University Leuven, KU Leuven, Belgium

L. Keviczky, Hungarian Academy of Sciences, Budapest, Hungary

V. Kučera, Czech Technical University in Prague, Prague, Czech Republic

R. Kennel, Technical University Munich, Germany

T.A. Kowalewski, Institute of Fundamental Technological Research PAN

E. Levi, Liverpool John Moore University, UK

G. Maier, Technical University of Milan, Milan, Italy

K.F. Man, City University of Hong Kong,

R. Maniewski, Institute of Biocybernetics and Biomedical Engineering PAN

H.A. Mang, Austrian Academy of Sciences, Vienna, Austria

H. Mihashi, Tohoku University, Aoba-ku, Sendai, Japan

S. Mindess, University of British Columbia, Vancouver, Canada

D.A. Mlynski, University of Karlsruhe, Karlsruhe, Germany

A.S. Nowak, University of Michigan, Ann Arbor, USA

K. Ohnishi, Keio University, Yokohama, Japan

A. Öberg, Linköping University, Linköping, Sweden

W. Pedrycz, University of Alberta, Canada

M. Razeghi, Northwestern University, Evanston, USA

J. Rodriguez, University of Andres Bello, Santiago, Chile

J.V. Sloten, Catholic University Leuven, Leuven, Belgium

B.M. Wilamowski, University of Auburn, Alabama, USA

A.L. Yarin, University of Illinois at Chicago, USA

Du Xiangwan, Chinese Academy of Engineering, China

J. Żurada, Department of Computer Engineering, University of Louisville, USA

Editorial Office:

Pałac Kultury i Nauki

Wydział IV Nauk Technicznych PAN

Pl. Defilad 1

PL 00-901 Warszawa

Managing Editor:

Renata Podraza, e-mail: Renata.Podraza@pan.pl

Finance:

Katarzyna Łasak, e-mail: Katarzyna.Lasak@pan.pl

The Bulletin of the Polish Academy of Sciences Technical Sciences is an open access journal with all content available with no charge in full text version.

The journal content is available under the licencse CC BY 4.0 https://creativecommons.org/licenses/by/4.0/.

Roczniki i numery
Instrukcja dla autorów
Dodatkowe informacje

Wybierz numer

Zawartość

Bulletin of the Polish Academy of Sciences Technical Sciences | Early Access

1 Enhancing Mobile Eye-Tracking in Extreme Urban Lighting Conditions

Marta Rusnak , Zofia Koszewicz , Franciszek Hackemer , Izabela Garaszczuk , Andrew T. Duchowski , Rafał Karnicki

Bulletin of the Polish Academy of Sciences Technical Sciences | Early Access | e152709 | DOI: 10.24425/bpasts.2024.152709

Słowa kluczowe: outdoor eye-tracking smart city data quality calibration sunlight

Pobierz PDF Pobierz RIS Pobierz Bibtex

Abstrakt

One of the methods for understanding residents' needs and socially improving urban spaces in terms of transportation, safety, landscape protection, and managing tourist traffic load is eye-tracking (ET). Researchers using mobile ET for outdoor studies face significant challenges, particularly due to sunlight affecting data quality. Existing solutions often overlook participant comfort. This article introduces a novel accessory designed for extreme lighting conditions, such as bright days, sunsets, and snowy or water-filled environments. The goal is to eliminate disruptions caused by uncontrolled sunlight on participants' eyes and enables studies in urban environments. A custom sun shield, designed for ETs based on spectacle frames, prioritizes both physical and psychological comfort. The lightweight shield is easy to install, minimally restricts the field of view, and does not interfere with eye-tracking components. It is cost-effective and suitable for DIY 3D printing. Control studies and field research confirmed its effectiveness, with feedback from over 100 users improving the final design. The shield enhances eye-tracking research credibility in sunny conditions, supports efficient calibration, and improves participant recruitment and well-being. Jakość danych znacząco wzrosła co obrazuje porównanie danych dotyczących sposobu detekcji źrenicy. Thanks to this solution, it will be possible to conduct research aimed at better understanding the behavior of city users, while ensuring their comfort and safety. It will also be possible to conduct research within the framework of so-called living labs. Importantly, studies show that the approach to designing subsequent mobile ETs based on IR should undergo significant modification.

Przejdź do artykułu

Autorzy i Afiliacje

Marta Rusnak

Zofia Koszewicz

Franciszek Hackemer

Izabela Garaszczuk

Andrew T. Duchowski

Rafał Karnicki

2 Slip Compensation Technique In Five-Phase Induction Motors Drive System

Krzysztof Blecharz , Roland Ryndzionek , Paul Gondran , Imad Merzouk

Bulletin of the Polish Academy of Sciences Technical Sciences | Early Access | e153223 | DOI: 10.24425/bpasts.2025.153223

Słowa kluczowe: five-phase induction motor multi-phase motor open-loop control slip compensation scalar control

Pobierz PDF Pobierz RIS Pobierz Bibtex

Abstrakt

The article presents a slip compensation method for traditional scalar (V/f) control of a five-phase induction motor. The proposed control method uses the possibility of injecting the third harmonic of voltage to increase the motor’s electromagnetic torque. The solution is characterized by both the simplicity of scalar control and improved speed control efficiency. The paper presents the PLECS simulation results and describes the laboratory tests that were conducted. The several scenarios were performed with dedicated and self developed algorithm in a laboratory stand using a 5-phase induction motor.

Przejdź do artykułu

Autorzy i Afiliacje

Krzysztof Blecharz

e-mail:

ORCID:

Roland Ryndzionek

e-mail:

ORCID:

Paul Gondran

Imad Merzouk

3 Experimental Studies on Reducing Permanent Magnet Losses Through Segmentation in a Fractional Slot PMSM Motor with High Power Density

Tomasz Wolnik , Tomasz Jarek , Jan Mikoś , Vitezslav Styskala

Bulletin of the Polish Academy of Sciences Technical Sciences | Early Access | e153225 | DOI: 10.24425/bpasts.2025.153225

Słowa kluczowe: eddy-current losses segmentation of permanent magnets high power density motors

Pobierz PDF Pobierz RIS Pobierz Bibtex

Autorzy i Afiliacje

Tomasz Wolnik

e-mail:

ORCID:

Tomasz Jarek

e-mail:

ORCID:

Jan Mikoś

Vitezslav Styskala

4 DODGE: Congestion Control in Manet via Dragonfly Optimized Deep Learning Model

S Gladson , K Pandiarajan

Bulletin of the Polish Academy of Sciences Technical Sciences | Early Access | e153231 | DOI: 10.24425/bpasts.2025.153231

Słowa kluczowe: MANET congestion node deep learning dragon fly optimization bidirectional long-short term memory

Pobierz PDF Pobierz RIS Pobierz Bibtex

Abstrakt

A mobile ad hoc network (MANET) is a collection of mobile devices attached without infrastructure or central management. Network size increases rapidly, resulting in congestion, network delay, data packet loss, a drop in throughput, resulting in poor energy efficiency. Data should be mitigated based on the prediction of congestion. To resolve the problem of congestion, a novel Dragonfly Optimized Deep learning for conGestion Elimination (DODGE) technique has been proposed which predicts the congested node effectively. Initially, the Transmission Control Protocol (TCP), User Datagram Protocol (UDP) packets from the MANET environment has been pre-processed and the features are selected using Dragon Fly Optimization (DFO). The features that are selected from the DFO model has been provided to the Stacked Convolutional Neural Network combined with Bidirectional Long Short-Term Memory (SCNN-BiLSTM). The Deep Learning network will predict the congested node and if congestion is found, then the message will be displayed. The DODGE is simulated by using Network simulator2 (NS2) and a comparison is made between proposed DODGE and traditional approaches such as Hybrid Gravitational Fuzzy Neural Network (HGFNN), Quality of Service-Aware Distributed Congestion Control (QoS-ADCC), and ImprovedPriority Aware-Ad Hoc On-Demand Distance Vector (IPA-AODV) in terms of Packet Delivery Ratio (PDR), Delay (DE), Throughput (TP), Energy Consumption (EC), Latency (L), Detection Rate (DR), and Network Lifetime (NL). The proposed SCNN-BiLSTM improves the overall accuracy better than 10.05%, 6.59%, 3.26% Bidirectional Long ShortTerm Memory (BiLSTM), Deep Neural Network (DNN), Convolutional Neural Network (CNN) for predict the congested node in the shortest time.

Przejdź do artykułu

Autorzy i Afiliacje

S Gladson

K Pandiarajan

5 Multilevel voltage source inverter with coupled reactors using coarsely quantized pulse amplitude modulation

Krzysztof Jakub Szwarc , Artur Cichowski , Paweł Szczepankowski , Janusz Nieznański , Ryszard Strzelecki

Bulletin of the Polish Academy of Sciences Technical Sciences | Early Access | 153227 | DOI: 10.24425/bpasts.2025.153227

Słowa kluczowe: multi-level inverter pulse amplitude modulation coupled reactors multi-pulse voltage source inverter

Pobierz PDF Pobierz RIS Pobierz Bibtex

Abstrakt

The paper discusses a multilevel voltage source inverter with coupled reactors (MVSI-CR). The output voltage is generated using the novel coarsely quantized pulse amplitude modulation (CQ-PAM). The AC voltage synthesis is realized by selecting and applying an appropriate collection of voltage vectors from the space-vector diagram. Integrating classical two-level inverters allows achieving modularity of the solution. The main advantage of the proposed approach is a very low switching-to-fundamental frequency ratio and a multistep quasisinusoidal output voltage. The paper includes a theoretical analysis, simulations, and laboratory test results.

Przejdź do artykułu

Autorzy i Afiliacje

Krzysztof Jakub Szwarc

Artur Cichowski

e-mail:

ORCID:

Paweł Szczepankowski

e-mail:

ORCID:

Janusz Nieznański

Ryszard Strzelecki

e-mail:

ORCID:

6 Study on Properties of Multipole Switched Reluctance Motor Designed for Multichannel Operation – Single Channel Operation Analysis

Mariusz Korkosz , Piotr Bogusz , Jan Prokop , Piotr Zasowski

Bulletin of the Polish Academy of Sciences Technical Sciences | Early Access | e153428 | DOI: 10.24425/bpasts.2025.153428

Słowa kluczowe: multi-channel spectrogram switched reluctance motor critical drive increased redundancy drive single channel operation

Pobierz PDF Pobierz RIS Pobierz Bibtex

Abstrakt

The following paper deals with the multipole design of the switched reluctance motor (SRM). The design is intended to facilitate the four-channel operation of the motor. Due to multipole design of the rotor and multichannel operation abilities, there are numerous possible configurations for powering the poles in each phase. Analysis of selected such configurations was carried out, including multichannel (MC) operating conditions (e.g. single-channel operation (SCO)). A mathematical model of three-phase MC SRM is presented. The static electromagnetic torque characteristics were obtained together with the self- and mutual inductance characteristics. Selected laboratory test results are presented in the paper.

Przejdź do artykułu

Autorzy i Afiliacje

Mariusz Korkosz

e-mail:

ORCID:

Piotr Bogusz

Jan Prokop

Piotr Zasowski

7 Analysis of the impact of the method of manufacturing the rotor on the parameters of an ACIPM machine

Mariusz Korkosz , Adrian Młot , Elżbieta Sztajmec , Karol Ryłło

Bulletin of the Polish Academy of Sciences Technical Sciences | Early Access | e153433 | DOI: 10.24425/bpasts.2025.153433

Słowa kluczowe: anisotropy cogging torque IPM motor electrical steel sheet torque ripple reduction

Pobierz PDF Pobierz RIS Pobierz Bibtex

Abstrakt

This article presents the technological problem related to the production of rotor with internal permanent magnet. Most often, the magnetic circuits of such rotors used in alternating current synchronous motors (AC IPM) are made of isotropic magnetic sheets. At this point, it should be noted that it is often not taken into account that each isotropic magnetic sheet exhibitssome anisotropy. This significantly affects the operational parameters of the brushless permanent magnet (PM) motor such as a cogging torque, electromagnetic torque ripples and an increase in induced voltage harmonics. To illustrate how important it is to properly design the rotor core, two rotors of the IPM motor were analysed in this work. In the first rotor solution, the minimisation of the anisotropy of the magnetic sheet was not taken into account, and the skew of the magnets was not used. In the second case of the IPM motor, the problem of anisotropy of the rotor magnetic circuit was minimised and an additional skew of the PMs was used. The obtained measurements and calculations of selected useful parameters of both rotor designs were compared with each other. Importantly, the conclusions and comments are extremely important for designers, assemblers and manufacturers of electrical machine components.

Przejdź do artykułu

Autorzy i Afiliacje

Mariusz Korkosz

e-mail:

ORCID:

Adrian Młot

e-mail:

ORCID:

Elżbieta Sztajmec

Karol Ryłło

8 Modeling the responsive structures under external forces using an evolutionary algorithm

Szymon Jankowski , Waldemar Bober

Bulletin of the Polish Academy of Sciences Technical Sciences | Early Access | e153432 | DOI: 10.24425/bpasts.2025.153432

Słowa kluczowe: responsive architecture for urban planning shape changing structures morphing urban structures smart city structures evolutionary algorithm structure behavior modeling

Pobierz PDF Pobierz RIS Pobierz Bibtex

Abstrakt

The design of responsive structures has evolved significantly, establishing itself as an interdisciplinary field characterized by a fully customized ideation process. To streamline and unify this process, a novel method for modeling the behavior of rod-like responsive structures using an evolutionary algorithm is introduced. The proposed mathematical framework leverages key geometric and physic parameters to control the generative process, enabling adaptability and fluidity in form development. By employing an evolutionary algorithm, the method offers an alternative to conventional rigid and repetitive morphing models, providing flexibility and innovation in responsive design outcomes. The developed model supports independent learning and fosters originality in solutions at both architectural and urban scales. Moreover, the presented methodology serves as the foundation upon which the authors developed the model, enabling its application across a wide spectrum of responsive structures for users. This paper addresses challenges in spatial modeling, behavioral algorithms, and the implementation of responsive architecture, presenting the author’s innovative model for rod-like responsive structures alongside performance analysis. The methodology demonstrates promising results in terms of adaptability and efficiency, with potential for further refinement to enhance speed and output quality. Research also describes challenges and risks for further development of responsive models implementation.

Przejdź do artykułu

Autorzy i Afiliacje

Szymon Jankowski

Waldemar Bober

9 Three-Axis Forces and Torque Sensor

Paweł Młotek , Piotr Mynarek , Marcin Kowol

Bulletin of the Polish Academy of Sciences Technical Sciences | Early Access | e153437 | DOI: 10.24425/bpasts.2025.153437

Słowa kluczowe: three-axis force and torque sensor optical measurement of force and torque STM microcontroller structural analysis

Pobierz PDF Pobierz RIS Pobierz Bibtex

Abstrakt

This paper describes research on a prototype of a multi-axis force and torque sensor dedicated to the support system of a telescopic camera crane arm. Based on studies conducted on an actual telescopic camera crane arm., the requirements that the sensor must meet to enable precise control of the drives in two working axes of the telescopic camera crane arm were defined. In the developed sensor, a method for measuring forces and torques using an optical displacement sensor was proposed. A simplified sensor prototype was made to verify the assumptions, and measurement tests were carried out. Additionally, the paper presents a CAD model of the sensor using an elastic pin, based on which a numerical model was developed, and calculations of displacements and mechanical stresses were performed.

Przejdź do artykułu

Autorzy i Afiliacje

Paweł Młotek

Piotr Mynarek

Marcin Kowol

e-mail:

ORCID:

10 The Fast Type-IV Discrete Sine Transform Algorithms for Short-Length Input Sequences

Marina Polyakova , Anna Witenberg , Aleksandr Cariov

Bulletin of the Polish Academy of Sciences Technical Sciences | Early Access | e153827 | DOI: 10.24425/bpasts.2025.153827

Słowa kluczowe: discrete sine transform matrix factorization fast algorithms computational complexity digital signal processing

Pobierz PDF Pobierz RIS Pobierz Bibtex

Abstrakt

The fast algorithms of discrete sinusoidal transform of the fourth type (DST-IV) for small-length input data in the range of lengths from 2 to 9 are developed. Fast algorithms for short input data sequences are subsequently used as building blocks for designing fast algorithms of large-sized discrete transforms. Applying the fast DST-IV algorithms for small-size block processing can reduce overall system complexity and delay, allowing detailed signal processing. As a result of the literature review, two main approaches to developing fast discrete sine transform (DST) algorithms were identified, namely, the polynomial algebraic approach and the matrix factorization approach. In the paper, the last approach is exploited. A matrix-vector product expression of the DST-IV is the starting point for designing the fast algorithms. Then based on the repetition and arranging of the matrix elements, the factorization of the matrices of coefficients of DST-IV is produced to reduce computational complexity. The correctness of the obtained algorithmic solutions was justified theoretically using a strict mathematical background of each of them. The elaborated algorithms were then further tested using MATLAB R2023b software to finally confirm their performance. The resulting factorizations of the DST-IV matrices reduce the number of multiplications by 63% but increase the number of additions by 8% on average in the range of signal sample numbers from 3 to 9. It has been observed that for even-length input sequences, the reduction in the number of multiplications is not as significant as for odd-length sequences. For some other well-known discrete trigonometric transforms (discrete Fourier transform, discrete Hartley transform) the opposite situation holds. The proposed DST-IV fast algorithms do not limit the length of the input data sequence to powers of two or three. The data flow graphs constructed for the proposed algorithms reveal their modular space-time structure suitable for VLSI implementation.

Przejdź do artykułu

Autorzy i Afiliacje

Marina Polyakova

Anna Witenberg

Aleksandr Cariov

Khishigjargal Gonchigsumlaa , Young Il Kim , Kun Min Yeo , Seong Hee Park , Yong Tae Lee

Bulletin of the Polish Academy of Sciences Technical Sciences | Early Access | e153828 | DOI: 10.24425/bpasts.2025.153828

Słowa kluczowe: optimal control multi-camera trajectory unmanned aerial vehicle entropy maximization surveillance area

Pobierz PDF Pobierz RIS Pobierz Bibtex

Abstrakt

The widespread use of unmanned aerial vehicles (UAVs) has heightened the demand for effective UAV monitoring, particularly in protected areas. Current learning-based detection systems depend heavily on camera sensors’ ability to capture UAVs in surveillance areas; however, advanced camera control methods remain limited. This paper proposes determining multi-camera trajectories that maximize UAV capture probability, ensuring UAVs remain within the camera’s field of view for further analysis, such as detection methods from camera-shot images. For this purpose, stochastic modelling is considered in the control framework for optimizing surveillance camera trajectories to enhance the probability of capturing UAVs. Key control parameters are derived through classical probability evaluations of the model with maximizing the entropy and covering trajectory-based strategies are applied. The reliability of stochastic system modeling is empirically validated through comprehensive computational experiments. These findings demonstrate the model’s potential to enhance UAV capture rates through optimized camera trajectories and coverage efficiency, paving the way for future advancements in real-environment applications.

Przejdź do artykułu

Autorzy i Afiliacje

Khishigjargal Gonchigsumlaa

Young Il Kim

Kun Min Yeo

Seong Hee Park

Yong Tae Lee

12 Bending behaviour of thin-walled perforated channel beams with modified cross sectional shape – Part 2: analytical calculations and FEM

Paweł Jasion , Aleksandra M. Pawlak , Piotr Paczos , Michał Plust , Marcin Rodak

Bulletin of the Polish Academy of Sciences Technical Sciences | Early Access | e153435 | DOI: 10.24425/bpasts.2025.153435

Słowa kluczowe: thin-walled channel beams web perforations four-point bending structural stability bucklinganalysis

Pobierz PDF Pobierz RIS Pobierz Bibtex

Abstrakt

This article is the second part of a comprehensive research program investigating the structural performance of thinwalled channels with modified cross-sectional geometries. The study involved testing six beams, three of which featured perforated webs, while the other three had flat, solid webs. The beams were subjected to four-point bending tests to evaluate their load-bearing capacity. The first part of the research presented the results of experimental tests and finite strip analysis. This article will focus on finite element analyses and analytical calculations conducted in accordance with Eurocode 3 guidelines and the principle of minimizing potential energy. The study provides several significant contributions: it integrates experimental, numerical, and theoretical methods to deliver a thorough evaluation of beam performance. The finite element method (FEM) simulations offer precise modeling of complex stress and strain states, while analytical calculations supply a solid theoretical foundation for interpreting structural behavior. The research demonstrates that web perforation, while reducing critical and maximum forces, also results in considerable weight savings, enhancing material efficiency. Additionally, the division of the research into two articles ensures clarity and accessibility, with this second part dedicated to detailed FEM and analytical results, thereby facilitating both academic understanding and practical engineering applications.

Przejdź do artykułu

Autorzy i Afiliacje

Paweł Jasion

e-mail:

ORCID:

Aleksandra M. Pawlak

e-mail:

ORCID:

Piotr Paczos

e-mail:

ORCID:

Michał Plust

e-mail:

ORCID:

Marcin Rodak

13 Thermal Transfer Performance of Downhole Electric Heaters for In-Situ Pyrolysis in Tar-Rich Coal

Ying Tang , Li Xiao , Fan Yang , Xiaodan Wu , Zhan Su , Yue Zhang , Shixin Jiang , Peng Yang

Bulletin of the Polish Academy of Sciences Technical Sciences | Early Access | e153839 | DOI: 10.24425/bpasts.2025.153839

Słowa kluczowe: tar-rich coal in-situ heat injection downhole heater thermal performance well-wall stability

Pobierz PDF Pobierz RIS Pobierz Bibtex

Abstrakt

The performance of a large-size helical baffle heater in an in-situ operating is investigated using a numerical simulation method. It revealed that the fluid in the shell retains a spiral flow, and the output flow velocity is higher than in the surrounding area. However, the pitch design is rather big, resulting in a low-velocity flow zone on the backwind side. At 100 kW and 500 m³/h, the fluid flow is turbulent. 50 kW and 200 m³/h, the fluid remained laminar. As flow rate rose, the pressure of tar-rich coal formation grew dramatically. The wall temperature exhibited spiral plunger at the inlet, but the bottom temperature was symmetrically distributed. Under low power and flow, Reynolds number change has a greater impact on the combination of Nusselt and Prandtl number. The wellbore experiences higher thermal loads during downhole heating, increasing the possibility of thermal damage dramatically. An increase in the heater shell length improves the total heat transfer performance. Conventional heaters often only heat the bottom formation. Therefore, while optimizing the construction, it is vital to ensure that the weight of heater itself does not exceed the tensile strength of cable, and consider shifting down the perforation outlet or lowering the outlet.

Przejdź do artykułu

Autorzy i Afiliacje

Ying Tang

Li Xiao

Fan Yang

Xiaodan Wu

Zhan Su

Yue Zhang

Shixin Jiang

Peng Yang

e-mail:

ORCID:

14 Numerical analysis of seal force in contacting finger seal

Yuan Wei , Bowen Ma , Yi Li , Kai-Uwe Schröder

Bulletin of the Polish Academy of Sciences Technical Sciences | Early Access | e153840 | DOI: 10.24425/bpasts.2025.153840

Słowa kluczowe: bending flexxible beam contacting finger seal seal force eccentricity numerical analysis

Pobierz PDF Pobierz RIS Pobierz Bibtex

Abstrakt

Finger seal is a flexible sealing device widely used in high-temperature and high-pressure environments such as gas turbine. Its force analysis is the key to design and optimize the performance of finger seal. At present most of the research on force analysis of finger seal are focused on the whole seal ring, but each finger beam has a different contacting performance with the shaft. In this work, a new force analysis method for contacting finger seal is proposed, as well as the model of finger seal with or without eccentricity is established to analyze the force of a single finger beam. The curved flexible finger beam is transformed into a straight one loaded with a certain moment at the end of it. The force acting on the finger beam is studied and compared with the existing reference to demonstrate the feasibility of the analysis method. By changing each parameter of the finger seal, the relationship between seal force and structural parameter is investigated. It shows that this method is meaningful to the calculation results of seal force for single finger beam, and can promote the development of finger seal and make it further in engineering application.

Przejdź do artykułu

Autorzy i Afiliacje

Yuan Wei

Bowen Ma

Yi Li

Kai-Uwe Schröder

15 Research on coordinated control of hydromechanical continuously variable transmission tractor mode switching based on model reference adaptation

Liyou Xu , Linkuan Zhang , Dongqing Wang , Mengnan Liu , Junjiang Zhang

Bulletin of the Polish Academy of Sciences Technical Sciences | Early Access | e154064 | DOI: 10.24425/bpasts.2025.154064

Słowa kluczowe: hydro-mechanical continuously variable transmission model reference adaptive control modeswitching coordinated control smoothness

Pobierz PDF Pobierz RIS Pobierz Bibtex

Abstrakt

Aiming at the problem that the difference between the speed of the hydraulic speed control system and the mechanical transmission speed is too large during the mode switching process of the equipped HMCVT tractor, which leads to the deterioration of the smoothness of the mode switching process, a mode switching coordination control strategy based on the model reference adaptive is proposed. Based on the mode switching process, the mathematical model of HMCVT mode switching is constructed; with the output speed of the hydraulic system as the reference model, the output speed of the mechanical transmission as the control object, and the output speed of the mechanical transmission following the output speed of the hydraulic system as the target, design model reference adaptive controller, based on the MATLAB simulation platform for the simulation test of the control strategy. The results show that when switching from H mode to HM1 mode, the maximum jerk is reduced by 70.3% and the slip friction work is reduced by 28.6%, and when switching from HM1 mode to H mode, the maximum jerk is reduced by 67% and the slip friction work is reduced by 28.9% compared to the use of the rule-based control strategy.

Przejdź do artykułu

Autorzy i Afiliacje

Liyou Xu

Linkuan Zhang

Dongqing Wang

Mengnan Liu

Junjiang Zhang

e-mail:

ORCID:

16 Study and Design of a Coaxial Magnetic Gear with a High Torque Density in Telescopic Camera Cranes

Piotr Warmuzek , Janusz Kołodziej , Marcin Kowol

Bulletin of the Polish Academy of Sciences Technical Sciences | Early Access | e154203 | DOI: 10.24425/bpasts.2025.154203

Słowa kluczowe: telescopic camera cranes magnetic gear magnetic torque torque ripple radial forces

Pobierz PDF Pobierz RIS Pobierz Bibtex

Abstrakt

Magnetic gears are slowly becoming a natural alternative to mechanical gears. Providing contactless, frictionless, and low-noise torque conversion, they are finding applications in renewable energy sources and electric vehicles, among others. This paper presents a comprehensive theoretical analysis with numerical calculations of a magnetic gear (MG) design for novel applications in telescopic camera cranes. Based on numerical simulations of selected MG variants, a potential transducer configuration was chosen that would meet the requirements of the drive transmission system - supporting the movement of the telescopic camera crane arm.

Przejdź do artykułu

Autorzy i Afiliacje

Piotr Warmuzek

Janusz Kołodziej

e-mail:

ORCID:

Marcin Kowol

e-mail:

ORCID:

17 Numerical Simulation of Transient Start-up Characteristics in Pump-Driven Two-Phase Flow Systems

Nianyong Zhou , Jing Li , Jixiang Liu , Kaiming Liu , Feifei Wang , Lianghui Liu

Bulletin of the Polish Academy of Sciences Technical Sciences | Early Access | e154202 | DOI: 10.24425/bpasts.2025.154202

Słowa kluczowe: pump two-phase flow heat transfer evaporative cold plate startup characteristic

Pobierz PDF Pobierz RIS Pobierz Bibtex

Abstrakt

The pump-driven two-phase flow system is widely used in electronic cooling due to its high heat transfer efficiency and stable temperature control. However, transient startup behaviors, crucial for reliability in dynamic thermal environments, remain poorly understood. This study addresses this gap by developing a simulation model using AMESim software with R134a as the working fluid, investigating the effects of heat load, pump speed, and cooling water temperature on startup dynamics. Results reveal three distinct startup types: Type I rising startup, Type II rising startup, and Type I falling startup. As the heat load increases from 2 kW to 5 kW, the system transitions from Type I to Type II, with the cold plate wall temperature decreasing by up to 27%. At 2 kW and 5 kW, the system exhibits Type I upward and Type II upward startup behaviors, respectively. Type II startup demonstrates reduced overshoot, enabling a quicker approach to quasi-steady state. At 2 kW, the system exhibits both single-phase and two-phase heat transfer, with the latter lowering the temperature by 2.26℃. Excessive subcooling can induce temperature oscillations within the evaporator. At a pump speed of 200 r/min, Type I upward startup is observed; however, increased speeds result in wall temperature overshoot. Furthermore, raising the cooling medium temperature from 10℃ to 40℃ elevates the evaporator wall temperature by 51.67%. By integrating quantitative metrics for overshoot, response time, and subcooling effects, this work provides actionable insights for optimizing pump-driven two-phase systems in high-heat-flux electronic cooling applications.

Przejdź do artykułu

Autorzy i Afiliacje

Nianyong Zhou

e-mail:

ORCID:

Jing Li

Jixiang Liu

Kaiming Liu

Feifei Wang

Lianghui Liu

18 Numerical simulation method of fork-flow condenser and the influence of fin structure characteristics

Kaiming Liu , Nianyong Zhou , Lianghui Liu , Benshi Han , Jing Li , Guanghua Tang , Jixiang Liu , Feifei Wang

Bulletin of the Polish Academy of Sciences Technical Sciences | Early Access | e154273 | DOI: 10.24425/bpasts.2025.154273

Słowa kluczowe: condenser multiphase flow priodic iteration numerical simulation heat transfer characteristics

Pobierz PDF Pobierz RIS Pobierz Bibtex

Abstrakt

Many researchers have investigated numerical simulation methods for two-phase flow in condensers. Still, challenges persist due to these models' large size, complex structure, and multiphase flow fields. To address these issues, this paper employs a periodic iterative numerical simulation approach for ultra-long condensers, validating the method through experiments and advancing the numerical simulation technology for such models. The study emphasises the impact of structural changes on the refrigerant and air sides. Results indicate that the most minor error occurs when the number of iterations in the two-phase zone does not exceed three. Increasing the total number of refrigerant channels from 10 to 18 enhances heat transfer by 17.7% and condensation capacity by 10.6%. However, further increases in channel numbers lead to a significant rise in pressure drop, deteriorating heat transfer performance. The heat transfer and condensation capacity improve with the height-to-width ratio of the refrigerant channel, reaching optimal performance when the ratio is close to 1. Additionally, increasing the aspect ratio on the air side will improve the heat transfer and condensation rate of the condenser. However, when the aspect ratio reaches 4.53, further increases will lead to a decrease in the heat transfer coefficient and an increase in pressure drop.

Przejdź do artykułu

Autorzy i Afiliacje

Kaiming Liu

Nianyong Zhou

e-mail:

ORCID:

Lianghui Liu

Benshi Han

Jing Li

Guanghua Tang

Jixiang Liu

Feifei Wang

19 Signed Networks with Laplacian Feedback: Observability and Minimal Sensor Problem

Vijayakumar S. Muni , Kallu Vetty Muhammed Rafeek , Gudala Janardhana Reddy , Deena Sunil Sharanappa

Bulletin of the Polish Academy of Sciences Technical Sciences | Early Access | e154061 | DOI: 10.24425/bpasts.2025.154061

Słowa kluczowe: multi-agent systems observability signed graph

Pobierz PDF Pobierz RIS Pobierz Bibtex

Abstrakt

In many multi-agent networks that evolve according to specific dynamical rules, our direct access is often limited to only a small subset of agents, known as “sensors.” The remaining agents in the network, whose states are entirely inaccessible, are referred to as “actuators.” If it is possible to retrieve the complete states of the actuators from the knowledge of the sensors’ states, the network is said to be “sensor– actuator observable”; otherwise, it is deemed unobservable. This research explores the analysis of sensor–actuator observability property (i.e., observable or unobservable) in networks where agent communications encompass both cooperation and competition (i.e., signed networks). It is assumed that the network’s agents continuously update their states within R under the Laplacian protocol. We simplify the Kalman’s and the PBH rank criteria for evaluating sensor–actuator observability property into several verifiable algebraic tests, emphasizing the significance of the system matrices’ spectral properties. This property is also examined from the perspective of the network’s graph topology. Sensor– actuator observability property is significantly influenced by the nature of agent communications and is often differs between signed and unsigned networks. However, we demonstrate that for a structurally balanced signed network, with specific set of sensors, it’s sensor–actuator observability property aligns with that of its unsigned variant. We present a formula utilizing Laplacian spectral information to determine the minimum number of sensors for an ensured sensor–actuator observable network. Applying the formula to path and cycle networks, it is found that paths are observable with one sensor, and cycles require two for observability.

Przejdź do artykułu

Autorzy i Afiliacje

Vijayakumar S. Muni

Kallu Vetty Muhammed Rafeek

Gudala Janardhana Reddy

Deena Sunil Sharanappa

20 A flying start method for sensorless induction machine-based electric drives

Daniel Wachowiak

Bulletin of the Polish Academy of Sciences Technical Sciences | Early Access | e154206 | DOI: 10.24425/bpasts.2025.154206

Słowa kluczowe: induction machine flying start speed observer sensorless drive DC injection

Pobierz PDF Pobierz RIS Pobierz Bibtex

Abstrakt

This paper presents an analysis of a proposed flying start method for sensorless electric drives based on an induction machine. The method introduces two stages. In the first stage, the rotor speed is estimated using the step response of the machine, which enables coarse estimation of the speed and direction of rotation, helping to reduce the initial slip. The second stage introduces an intermediate control system to facilitate the machine restart and assist the speed observer in converging. Simulation and experimental studies demonstrate that the method successfully restarts the machine with unknown initial rotor speed without exceeding the nominal current. The auxiliary control system fully excites a 5.5 kW machine within 300 ms during the flying start, after which it is possible to transition to the target control system.

Przejdź do artykułu

Autorzy i Afiliacje

Daniel Wachowiak

e-mail:

ORCID:

21 Processing and analysis of trolleybus traction data using LINQ technology

Andrzej Wilk , Mikołaj Bartłomiejczyk , Jacek Skibicki , Leszek Jarzębowicz , Dariusz R. Karkosinski , Łukasz Hupka , Jan Hupka , Paweł Kaczmarek , Natalia Karkosinska-Brzozowska

Bulletin of the Polish Academy of Sciences Technical Sciences | Early Access | e154144 | DOI: 10.24425/bpasts.2025.154144

Słowa kluczowe: trolleybuses traction batteries exploatation and maintaining

Pobierz PDF Pobierz RIS Pobierz Bibtex

Abstrakt

The paper presents the processing and analysis of the recorded trolleybus data using the LINQ (Language Integrated Query) software technology. The trolleybus data acquisition system collects a huge amount of electromechanical data in real time during the vehicle operation. These data are used for the analysis in post-processing mode. In this paper, the data processing has been performed to assess the technical condition of trolleybus batteries. Selected standard query operators of the LINQ technology have been implemented in the Windows Presentation Foundation (WPF) application to process the data and to determine the charge and energy stored in the battery. The LINQ technology has been proven to be useful for analysing large amounts of data recorded from trolleybuses.

Przejdź do artykułu

Autorzy i Afiliacje

Andrzej Wilk

e-mail:

ORCID:

Mikołaj Bartłomiejczyk

Jacek Skibicki

Leszek Jarzębowicz

Dariusz R. Karkosinski

Łukasz Hupka

Jan Hupka

Paweł Kaczmarek

Natalia Karkosinska-Brzozowska

22 A Markov Chain Model to Determine Optimal Maintenance Policy for Production Process

Mohammad Saber Fallah Nezhad , Mohammad Hossein Kargar Shouroki , Shahaboddin Kharazami

Bulletin of the Polish Academy of Sciences Technical Sciences | Early Access | e154065 | DOI: 10.24425/bpasts.2025.154065

Słowa kluczowe: discrete-time Markov chain maintenance policy optimum policy cost minimization

Pobierz PDF Pobierz RIS Pobierz Bibtex

Abstrakt

This paper considers an operating machine with deteriorating performance over time. Initially, functioning at 100% of its nominal capacity, the machine fails after a stochastic period, reducing its capacity to a proportion of the nominal level. In this degraded capacity state, three maintenance and repair policy options are available for evaluation. By modeling the system as a discrete-time Markov chain and analyzing the probability transition matrix between the system states, the costs associated with the loss of production, part replacement, and ongoing operation in each state can be quantified. The objective function representing the average cost per unit time of production is calculated to determine the optimal maintenance policy. Different policies are modeled by Markov chain and the average cost of each policy are obtained. The results demonstrate the applicability of the proposed methodology to evaluating different policies.

Przejdź do artykułu

Autorzy i Afiliacje

Mohammad Saber Fallah Nezhad

Mohammad Hossein Kargar Shouroki

Shahaboddin Kharazami

23 EMF Signature Analysis in a Marine-Type Brushless Synchronous Generator for Online Fault Detection

Filip Kutt , Michał Michna , Grzegorz Kostro

Bulletin of the Polish Academy of Sciences Technical Sciences | Early Access | e154207 | DOI: 10.24425/bpasts.2025.154207

Słowa kluczowe: generator maintenance diagnostic marine ship

Pobierz PDF Pobierz RIS Pobierz Bibtex

Autorzy i Afiliacje

Filip Kutt

e-mail:

ORCID:

Michał Michna

e-mail:

ORCID:

Grzegorz Kostro

e-mail:

ORCID:

24 Strain-controlled uniaxial fatigue of an AA2519 aluminum alloy sheet

Łukasz Pejkowski , Maciej Kotyk

Bulletin of the Polish Academy of Sciences Technical Sciences | Early Access | e154271 | DOI: 10.24425/bpasts.2025.154271

Słowa kluczowe: AA2519 aluminum alloy sheet metal fatigue life

Pobierz PDF Pobierz RIS Pobierz Bibtex

Abstrakt

This study provides a comprehensive investigationŁ of the uniaxial, strain-controlled fatigue behavior of an AA2519 aluminum-copper alloy. The alloy was characterized in the as-fabricated state. Three orientations relative to the rolling direction were used to determine the mechanical properties. The quasistatic strength and cyclic stress‒strain response of the AA2519 aluminum alloy for the examined cases were similar regardless of the rolling direction, although slight differences between them were noticeable. Similarly, the fatigue life was not strongly affected by the specimen orientation. The investigation also included fractographic analysis of the fracture surfaces, revealing differences between strain amplitude levels and specimen orientations. The experimental results obtained provide a good basis for engineering applications of the analyzed AA2519 alloy and offer a solid foundation for further research into the effect of heat treatment on the fatigue strength of the investigated alloy.

Przejdź do artykułu

Autorzy i Afiliacje

Łukasz Pejkowski

Maciej Kotyk

25 Tribological properties of plasma sprayed NiAlAg-Ta-Cr₂O₃ composite lubrication coatings from room temperature to 750 C

Chengqi Yan , Xiaopeng Miao , Zhuying Jia , Fei Zhao , Yong Zhang

Bulletin of the Polish Academy of Sciences Technical Sciences | Early Access | e154275 | DOI: 10.24425/bpasts.2025.154275

Słowa kluczowe: lubricating coatings plasma spraying silver tantalate wide temperature range

Pobierz PDF Pobierz RIS Pobierz Bibtex

Abstrakt

With the rapid advances in science and technology, the core parts and techniques in tribo-systems rely on the solidlubricating materials at wide-temperature range for durability, especially for designing and producing materials with low friction coefficient and high wear resistance over a wide temperature ranges. In this paper, a series of NiAl-Ag-Ta-Cr₂O₃ composite coatings with different contents of Ta and Ag were deposited by plasma spraying, their tribological properties at RT-750 C under dry sliding conditions were investigated by a ball-on-disk tribometer. The friction products and compositions of worn surface at different temperature were investigated. The deposited NiAl-Ag-Ta-Cr₂O₃ composite coatings exhibited excellent wear resistance at RT (10^-7 mm³ /N m), while the friction coefficients lower than 0.5 at RT to 750 C. The contents of Ta and Ag decided mechanical properties of coatings, and greatly affected the tribological properties by creating an tribo-film (lubricant film and glaze layer). NiAl-10Ag-5Ta-20Cr₂O₃ coating shows better tribological properties over all temperature, while the wear rate reduces to 5 58×10^-6 mm³ /N m at 750 C and the friction coefficient reduces to 0.21 at 600 C. The excellent lubrication and wear resistance of composite coatings at high temperatures are mainly attributed to the Ag acted as lubrication phase, and the top surface of wear track was covered with a smooth glaze layer, which consisted of Ag, Ta₂O₅, Cr₂O₃ and AgTaO₃. In addition, the lubrication mechanism of silver tantalate was also briefly discussed.

Przejdź do artykułu

Autorzy i Afiliacje

Chengqi Yan

Xiaopeng Miao

Zhuying Jia

Fei Zhao

Yong Zhang

26 Feasibility Study on In-Situ Heat Injection of Tongchuan Oil Shale and Tar-Rich Coal Based on TG-DTG

Heping Yan , Xiurong Wu , Qiang Li , Yinghui Fang , Qingfeng Bu

Bulletin of the Polish Academy of Sciences Technical Sciences | Early Access | e154274 | DOI: 10.24425/bpasts.2025.154274

Słowa kluczowe: in-situ conversion tongchuan oil shale TG-DTG pyrolysis characteristic

Pobierz PDF Pobierz RIS Pobierz Bibtex

Abstrakt

In-situ thermal injection is an effective development method for low-value unconventional resources. The non-isothermal pyrolysis characteristics of Tongchuan oil shale and tar-rich coal were investigated by TG-DTG extrapolation. In addition, the pyrolyzed shale oil was analyzed. It results shows that the pyrolysis of oil shale and tar-rich coal can be divided into three stages. The pyrolysis temperature intervals of the both can be consistent. Compared with the oil shale, ignition temperature of the mixed decreased by 2.3% and burnout temperature increased by 1.4%. The pyrolysis index increased by 40.3%, the pyrolysis stability increased by 66.7%, and the content of oxygenated compounds increased by 552.4%. The conversion of oxygenated compounds to phenolic compounds was inhibited at the 20°C/min heating rate. In the air, the excessively fast heating rate caused the tar to condense earlier and coking on the sample surface. The pyrolysis index of the mixed decreased from 3.2 to 1.8 times, while the pyrolysis stability increased by 6.7 times, respectively. The introduction of excessive oxygenated groups by the air increased the content of oxygenated compounds in the mixed by 485.44%. while the aromatic hydrocarbons decreased by 17.97%. It can be seen that the co-pyrolysis of oil shale and tar-rich coal can improve the ignition characteristics of oil shale. The co-pyrolysis of oil shale and tar-rich coal not only conforms to the distribution characteristics of the both, but also greatly cooperates with the topical chemical reaction method.

Przejdź do artykułu

Autorzy i Afiliacje

Heping Yan

Xiurong Wu

Qiang Li

e-mail:

ORCID:

Yinghui Fang

Qingfeng Bu

27 Discrete Non-Integer Order Model of Synchronous Generator for Power Hardware In the Loop Implementation

Szymon Racewicz , Filip Kutt , Łukasz Sienkiewicz , Michał Michna , Roland Ryndzionek

Bulletin of the Polish Academy of Sciences Technical Sciences | Early Access | e154272 | DOI: 10.24425/bpasts.2025.154272

Słowa kluczowe: non-integer order modeling synchronous generator power hardware in the loop PHIL

Pobierz PDF Pobierz RIS Pobierz Bibtex

Abstrakt

Non-integer order modelling is used for a better description of different nature physical phenomena which leads to more compact and knowledge-based models. The main objective of the presented study is to apply the non-integer order model of synchronous generator (SG) in the Power Hardware In the Loop (PHIL) technique which is readily used for i.e. design, research and development, maintenance or service purposes. The developed model was prepared and run in the MATLAB/Simulink software using a discrete solver. To discretize the non-integer order model, the Z-transform was applied and the half-order derivatives and integrals present in the model’s equations were evaluated using Oustaloup approximation. Finally, the model was validated on the measurements of the 125 kVA SG connected to the active-reactive loads of different values and compared with the classical integer order one.

Przejdź do artykułu

Autorzy i Afiliacje

Szymon Racewicz

e-mail:

ORCID:

Filip Kutt

e-mail:

ORCID:

Łukasz Sienkiewicz

e-mail:

ORCID:

Michał Michna

e-mail:

ORCID:

Roland Ryndzionek

e-mail:

ORCID:

28 Flower Pollination Algorithm Optimization Applied for Lyapunov-based Fuzzy Logic Speed Controller of a Complex Drive System

Grzegorz Kaczmarczyk , Radosław Stanisławski , Łukasz Knypiński , Danton Diego Ferreira , Marcin Kamiński

Bulletin of the Polish Academy of Sciences Technical Sciences | Early Access | e154205 | DOI: 10.24425/bpasts.2025.154205

Słowa kluczowe: flower pollination algorithm fuzzy logic controller two-mass system electric drives

Pobierz PDF Pobierz RIS Pobierz Bibtex

Abstrakt

With the current trends in manipulator design, plentiful examples of machines with flexible links and joints can be instantiated. Lighter construction that allows bending and torsion offers multitude of advantages, such as lower energy consumption and better operation safety when collision is possible in the working environment. However, precise control of applications with such mechanical constructions is very challenging. The state variables might be affected by torsional vibrations, and identification of controller parameters is more difficult, which makes the controller tuning complicated. Therefore, this work focuses on tackling the issues related to speed control of electric drives with sophisticated, and elastic couplings. The robustness against parameter uncertainty is provided through the use of a fuzzy logic system. The speed controller design process incorporates the selection of the rule base, designation of membership functions, as well as controller gain optimization using a nature-inspired technique - the Flower Pollination Algorithm (FPA). Increased damping of torsional vibrations, as well as decreased sensitivity to inertia changes is expected compared to other conventional control solutions, such as PI control. In this study both numerical and experimental studies are conducted.

Przejdź do artykułu

Autorzy i Afiliacje

Grzegorz Kaczmarczyk

e-mail:

ORCID:

Radosław Stanisławski

Łukasz Knypiński

e-mail:

ORCID:

Danton Diego Ferreira

e-mail:

ORCID:

Marcin Kamiński

29 Design and Implementation of Non-circular Gears Based on Target Transmission Ratio

Weizhen SONG , Yong HE

Bulletin of the Polish Academy of Sciences Technical Sciences | Early Access | e154227 | DOI: 10.24425/bpasts.2025.154277

Słowa kluczowe: non-circular gear target transmission ratio kinematic analysis tooth profile extraction equal arc length algorithm

Pobierz PDF Pobierz RIS Pobierz Bibtex

Abstrakt

Addressing the complexities inherent in current specific non-circular gear design, including the extensive computational demands involved in solving tooth profile feature points and the lack of a rigorous design and verification process, this study proposes a design method grounded in gear meshing theory. Specifically, the method focuses on achieving the target transmission ratio for non-circular gear. First, the pitch curve equation for the non-circular gear is computed. Secondly, an equal arc length algorithm is proposed to determine the polar diameter rotation angle corresponding to the same arc length per turn, generating a non-circular gear envelope diagram using the equal arc length enveloping method. Subsequently, an edge extraction algorithm is presented to obtain the tooth profile feature data. After obtaining tooth profile feature data, the 3D model of non-circular gears are generated. Then, the gear pair is virtually assembled, and the meshing process is analyzed using a motion simulation method. The results show that the tooth profile meshes well, and the angular velocity curve of the driven wheel is consistent with the target transmission ratio. Finally, the processed non-circular gear was inspected, and the results indicated that the error between produced non-circular gear and the theoretical tooth profile was within a reasonable range. This confirms the accuracy of the proposed method and provides a rigorous design and verification process for non-circular gears, which is beneficial for further analysis in manufacturing and other tasks. This method not only significantly reduces computation time but also simplifies the process of extracting tooth profile feature points, ensuring extraction accuracy.

Przejdź do artykułu

Autorzy i Afiliacje

Weizhen SONG

Yong HE

30 Dynamics Analysis on Cavitation Flow Field of Centrifugal Pumps using Modal Order Reduction

Yancheng Zhang , Lei Zhang , Cong Wang , Tengjiao Sun , Z. Li , Dezhi Jiang

Bulletin of the Polish Academy of Sciences Technical Sciences | Early Access | e154280 | DOI: 10.24425/bpasts.2025.154280

Słowa kluczowe: centrifugal pump cavitation flow field modal, analysis dynamic modal decomposition

Pobierz PDF Pobierz RIS Pobierz Bibtex

Abstrakt

Throughout the operational lifecycle of centrifugal pumps, cavitation is an omnipresent phenomenon that frequently leads to cavitation erosion and a decline in hydraulic heads, leading to mechanical failures and substantial damages to the pump assembly. Although the cavitation phenomenon has been widely studied in existing literature, it is still a challenging task for reliable flow dynamics analysis of the centrifugal pumps using the modal order reduction technique. In this study, the modal decomposition and reconstruction of the flow field of a centrifugal pump with considering the cavitation are carried out. The dynamic modal decomposition (DMD) based on the singular value decomposition (SVD) is employed to explore the dynamic behavior of the cavitation flow field by reducing the modal order of the flow field. Then, the modal characteristics of the pump flow field are systematically analyzed. The results demonstrate that the DMD method can improve the accuracy of the order reduction model and reduce the modal reconstruction error, the reconstruction error loss is less than 5%, and the calculation efficiency is significantly enhanced to analyze the pump cavitation flow field. In addition, through comparing the calculation data between the finite element simulation and the DMD reconstructed flow field, it indicates the potential application of the DMD method in investigating the degradation of the flow field due to cavitation, which provides new perspective and solid technique support for centrifugal pump cavitation analysis.

Przejdź do artykułu

Autorzy i Afiliacje

Yancheng Zhang

Lei Zhang

e-mail:

ORCID:

Cong Wang

Tengjiao Sun

Z. Li

Dezhi Jiang

Instrukcja dla autorów

Guide for Authors

https://www.editorialsystem.com/bpasts/journal/for_authors/

As of January 1st, 2025, there are changes in the fees for open access publications in Bulletin of the Polish Academy of Sciences Technical Sciences: 2000 PLN (approx. 500 EUR) - up to 8 pages of the journal format and mandatory over-length charges of 250 PLN (approx. 60 EUR) per page (see the above link with instructions for Authors for details)

Guide for Reviewers

https://www.editorialsystem.com/bpasts/journal/for_reviewers/

Call for Papers

https://www.editorialsystem.com/bpasts/journal/call_for_papers/

Guide for Guest Editors

https://www.editorialsystem.com/editor/bpasts/journal/page1/

Dodatkowe informacje

NEW PUBLICATION FEES
Articles submitted by December 31st, 2024: existing fee: 1500 PLN (and mandatory over-length charges of 230 PLN per page)
Articles submitted from January 1st, 2025: new fee: 2000 PLN (approx. 500 EUR- depending on the exchange rate) - a flat fee per paper up to 8 pages of the journal format (each additional page will be charged an additional 250 PLN).