Wyniki wyszukiwania - BazTech

1

Experimental analysis of diving fins energy efficiency using hydrodynamic modelling

Grządziela Andrzej, Szymak Piotr, Kluczyk Marcin, Praczyk Tomasz, Piskur Pawel, Hożyń Stanisław, Batur Tomislav

Advances in Science and Technology. Research Journal

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2026

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Vol. 20, no. 6

368--380

EN

This study presents a research methodology and test setup to analyze different types of recreational fins for specific tasks: beginner recreational swimming, deep-water diving, and sports swimming. The fins tested were Aqualung, Scubapro, and Exotech. The primary goal is to present the diving fins research methodology, experimental results, and conclusions. The study achieves high reliability in real-world conditions by combining experimental design with mathematical models based on hydrodynamic similarity. Key to this approach is conducting methodologically sound experiments on a controllable object, allowing precise energy measurements of the swimmer's leg. Despite the challenges posed by the variable thrust force of diving fins in different leg positions, this method remains the most reliable way to integrate experimental data with hydrodynamic theories in comprehensive, multivariate research. Presented results show that fin energy efficiency strongly depends on the interaction between fin geometry, flexural stiffness, and swimming style, with different fin designs achieving maximum efficiency under different operating conditions.

2

Influence of Butanol-Diesel Oil Fuel Blends on Marine Engine Vibration Characteristics

Kluczyk Marcin

Advances in Science and Technology. Research Journal

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2024

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Vol. 18, no. 5

372--384

EN

One of the primary sources contributing to vibrations in operational marine diesel engines is the combustion process of fuel injected into the cylinders. Hence, alterations in the injection process and the quality and type of fuel supplied to the engine can modulate the combustion parameters, consequently impacting noise and vibration levels. A literature review on this subject suggests that while some research has been conducted, mainly focusing on small engines in the automotive sector, there's been limited exploration in the marine domain. Despite the recent surge in manufacturers' interest in electrifying road transport vehicles, a similar trend has not been observed in sea transport besides short-range ferries, mainly due to the substantial range requirements of vessels. It is conceivable that the utilisation of liquid fuels in shipbuilding will persist. Presently, the predominant marine fuels are fossil-based, the reserves of which are progressively declining. However, the widespread adoption of alternative fuel additives like butanol holds promise in curbing fossil fuel consumption. One of the conditions to be met by a new commonly used fuel for marine engines is its good properties in limiting the parameters of accompanying processes like vibrations. The article delineates a comparative analysis of parameter values related to the vibrations of a marine engine fueled by different blends of butanol and diesel oil. Laboratory tests were conducted on a six-cylinder marine engine under load using a water brake, encompassing various engine loads to replicate real-world operating conditions accurately.

3

Kinematic and Dynamics Modeling of Nonholonomic Mobile Robot

Jasiński Krzysztof, Murawski Lech, Szeleziński Adam, Kluczyk Marcin

Scientific Journal of Gdynia Maritime University

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2023

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nr 128

33--56

EN

This paper presents computer simulation results of kinematic and dynamic of two and three – wheeled mobile robot, conducted in the Matlab&Simulink packet environment. Models of kinematics and dynamics were developed with the aid of Jacobians and Lagrange II multiplayers equations.

4

Influence of Added Water Mass on Ship Structures Vibration Parameters in Virtual and Real Conditions

Doan Do Van, Murawski Lech, Szeleziński Adam, Muchowski Tomasz, Kluczyk Marcin, Muc Adam, Jasiński Krzysztof, Chodnicki Marek

Scientific Journal of Gdynia Maritime University

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2023

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nr 128

57--77

EN

Modeling of ship structures in a virtual environment is now standard practice. Unfortunately, many engineers forget about considering the influence of added water on the frequency values and the amplitude of natural vibrations. The article presents the effect of water damping on the frequency values of the individual natural vibration modes. The tests were carried out in two stages, first, the mentioned values were determined using FEM and then the values obtained in this way were compared with the parameters measured during laboratory tests. For the needs of laboratory measurements, structural elements made of ship steel in one of the Polish shipyards were used. All welds of the test objects have been verified in terms of their correctness. Irregularities in the execution of welded joints could result in a measurement error that is difficult to identify. As a result of the tests, the percentage differences in the frequency of occurrence of natural vibrations of individual modes were determined according to added water mass considerations. Importantly, the research concerned a real structural element of the hull, and the obtained results confirm the need to take into account the mass of accompanying water during the hull's FEM analysis. A number of more detailed research results were obtained, the most important of which is the fact that the finite element method is a valuable method for assessing the dynamics of wetted structures - the error in determining the vibration frequency did not exceed 5% for basic modes. The method of modeling the tested structures was almost equally important - the discrepancy of the results reached 4% depending on the modeling method. When designing marine SHM systems, it is essential to consider the effect of added water mass, since the frequency variations of a damaged structure relative to an undamaged one, are of the same order as the effect of added water.

5

Multi-symptom measurement based fault detection of the PEM fuel cell system

Polak Adam, Kluczyk Marcin

International Journal of Applied Mathematics and Computer Science

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2023

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Vol. 33, no. 2

197--205

EN

The proper functioning of the fuel cell system depends on the proper operation of all its subsystems. One of the key subsystems is the oxidant supply system, which is responsible for supplying oxygen for the electrochemical reaction taking place in the cell. It also transports the reaction products, i.e., water, outside the fuel cell stack, and in some cases removes excess heat generated in the stack. Changes in the technical condition of machine individual elements always result in changes in operating or residual parameters; however, it is necessary to select appropriate diagnostic methods to be able to use these changes to assess the machine’s technical condition. This article presents the results of research focused on assessing the possibilities of diagnosing the oxidant supply subsystem, in particular, too low an oxidant flow leading to oxygen starvation and cathode flooding, based on the analysis of the voltage occurring in individual cells of the stack as well as on the basis of vibration and acoustic emission (AE) measurements. The presented results show that the faulty operation of that system can be indicated either through electrical and vibroacoustic/acoustic emission measurements.

6

Selected Aspects of 3D Printing for Emergency Replacement of Structural Elements

Jasiński Krzysztof, Murawski Lech, Kluczyk Marcin, Muc Adam, Szeleziński Adam, Muchowski Tomasz, Chodnicki Marek

Advances in Science and Technology. Research Journal

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2023

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Vol. 17, no. 1

274--289

EN

The paper presents a synthetic characterization of modern methods of manufacturing or regenerating machine elements. Considered methods are machining and additive methods, in particular 3D printing in the FDM/FFF technique. For the study, the authors made samples of the holder bracket using selected methods. Samples made by machining operations, 3D printing with various filling were tested. The paper contains a technical and economic analysis of the production of a holder bracket using the discussed methods. The dynamics of steel and FDM/FFF printed samples were also assessed by determining their resonance curves. The vibration magnification fac-tors were analyzed - the quotient of the vibration amplitudes in the resonance to the static deformations that occurred under the influence of the constant force and the location of the vibration resonances - the natural frequencies for individual vibration modes. The study's main objective is to assess the possibility of emergency changing the manufacturing technology of selected machine components. The authors were interested in partially replacing costly and not environmentally friendly milling with 3D printing. Machine elements can be manufactured by printing in classical machine building and emergency conditions to replace a damaged component temporarily (e.g., on a ship, for the time of arrival at a port or shipyard). The main assumption guiding the authors during the preparation of this publication was the analysis of the possibility of using the production of "ad hoc" prepared spare parts and their use in the event of a lack of access to parts made of the intended materials.

7

Comparison of calculating algorithms for logarithmic decrements applied to welded joints assessments

Szeleziński Adam, Muc Adam, Murawski Lech, Muchowski Tomasz, Kluczyk Marcin, Jasiński Krzysztof, Antczak-Jarząbska Romana

Scientific Journal of Gdynia Maritime University

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2022

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nr 124

7--19

EN

There are numerous non-destructive methods in welded joints investigation, but the most promising, especially in applications with steady monitoring of the structure, is the vibro-diagnostic approach. In the course of the research work, the responses were obtained and detected by accelerometers, providing valuable diagnostic information, which later was mathematically processed in the field of time or frequency. The mathematical processing aimed to distinguish significant characteristics embedded in the processes typical of the investigated joints and allow an assessment of how they were made. For this purpose, two methods were proposed, based on determining the logarithmic decrement as a function of time. Due to the complicated course of the impact responses, the method of calculating the logarithmic decrement has been suggested, involving the approximation of responses with various functions. According to the research, the analysis of changes in the logarithmic decrement as a function of time applied to welded plates was proposed, as it enables the initial assessment of joint quality.

8

Design and operational diagnostics of marine propellers made of polymer materials

Kluczyk Marcin, Grządziela Andrzej, Batur Tomislav

Polish Maritime Research

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2022

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nr 4

115--122

EN

There has been a rapidly growing interest in the use of composite and polymer materials for the construction of marine propellers for over 20 years. The main advantages of these materials are a reduction in the weight of the propeller, increased efficiency due to the hydroelasticity effect, a reduction of the hydroacoustic signature, and a cost reduction for serial production. This paper presents an overview of diagnostic methods that can be applied at the design level and during the operation of marine propellers made of polymeric materials. Non-invasive contact and non-contact-based diagnostic techniques for evaluating the technical state of the propeller are reviewed, and the advantages and disadvantages of qualitative and quantitative methods are identified. Operational diagnostic procedures for propellers are areessential for the safety of vessels at sea. Finally, the structure of a diagnostic system is proposed. It combined diagnosis process with the genesis of damage and the prognosis of the technical condition, i.e. production and in-service diagnostics.

9

The process of acquiring, collecting, processing and archiving data for the SHM system designed to identify defects in thin-walled structures

Muchowski Tomasz, Szeleziński Adam, Murawski Lech, Muc Adam, Kluczyk Marcin

Journal of KONBiN

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2022

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Vol. 52, iss. 4

135--142

EN

The article shows the results of the preparatory steps taken to create the artificial intelligence used in the automatic recognition of defects in ship thin-walled structures. The above steps are used to create a university private cloud and a computer system maintaining a dataset of vibration signal samples. In the article, a prototype of the private cloud was designed and developed, a model of the vibration sample was prepared, and a microservice was designed aimed at sharing the obtained data. The article demonstrates the results of the completed development.

PL

W artykule przedstawiono wyniki przeprowadzonych działań przygotowawczych do stworzenia sztucznej inteligencji wykorzystywanej w automatycznym rozpoznawaniu defektów okrętowych konstrukcji cienkościennych. Przeprowadzone kroki służą stworzeniu uczelnianej chmury prywatnej oraz systemu informatycznego utrzymującego zbiór danych próbek sygnałów drganiowych. W ramach artykułu zaprojektowano oraz stworzono prototyp chmury prywatnej, przygotowano model próbki drganiowej oraz zaprojektowano mikroserwis służący udostępnianiu uzyskanych danych. Artykuł przedstawia wyniki wykonanej pracy.

10

Analysis of the possibility of using vibration parameters for diagnostics of selected defects in welded joints of the hull plating elements

Muchowski Tomasz, Szeleziński Adam, Murawski Lech, Muc Adam, Kluczyk Marcin

Journal of KONBiN

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2022

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Vol. 52, iss. 3

165--174

EN

The article presents results of vibration tests of thin-walled plates used in shipbuilding for plating hulls of vessels. The conducted tests were aimed at determining the possibility of using measurements of vibration acceleration recorded on the tested objects as parameters enabling the detection of damages in the performed welded joints. Seven plates were compared, six of which had joints in different technical conditions, and one was a board without a weld. The quality of the welds was verified using X-ray methods. The adopted research methodology and the obtained results were presented.

PL

W artykule przedstawiono wyniki badań drganiowych płyt cienkościennych wykorzystywanych w okrętownictwie jako poszycie kadłubów jednostek pływających. Przeprowadzone badania miały na celu określenie możliwości stosowania pomiarów przyspieszeń drgań rejestrowanych na badanych obiektach jako parametrów umożliwiających wykrycie uszkodzeń w wykonanych połączeniach spawanych. Porównano siedem płyt, z czego sześć miało spoiny w różnym stanie technicznym, a jedna była bez spawu. Jakość spoin zweryfikowana została metodami RTG. Przedstawiono przyjętą metodykę badawczą oraz uzyskane wyniki.

11

Analysis of the Use of Undervolting to Reduce Electricity Consumption and Environmental Impact of Computers

Muc Adam, Muchowski Tomasz, Kluczyk Marcin, Szeleziński Adam

Rocznik Ochrona Środowiska

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2020

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Tom 22, cz. 2

791--808

EN

This paper presents a method of lowering the processor’s voltage and temperature in which the computer operates by performing an operation called undervolting. By using undervolting it is possible to reduce electricity consumption and the amount of heat generated by computer workstations by up to 30%. This problem is particularly relevant for institutions that use a large number of computers. The more the computers are subjected to the higher computational load, the more effective the mechanism of undervolting is. Undervolting the processor does not reduce its performance, but lowers its operating temperature, has a positive impact on its life span and power consumption. Maintaining a low temperature of operation for computer hardware is essential to reduce operating and repair costs. The paper also presents the results of environmental research aimed at assessing the validity and effectiveness of undervolting.

PL

W pracy przedstawiono metodę obniżania napięcia procesora i temperatury pracy komputera poprzez wykonanie operacji zwanej undervoltingiem. Przez zastosowanie undervoltingu można obniżyć nawet o 30% zużycie energii elektrycznej i ilość wydzielanego ciepła przez stanowiska komputerowe. Problem ten jest szczególnie istotny w przypadku instytucji, które korzystają z dużej liczby komputerów. Skuteczność mechanizmu jest tym większa im komputery poddane undervoltingowi są bardziej obciążone obliczeniowo. Wykorzystywanie undervoltingu w konfiguracji procesora nie zmniejsza jego wydajności, a obniża jego temperaturę pracy, wpływa pozytywnie na jego żywotność i zużycie energii elektrycznej. Utrzymanie dobrej kultury pracy sprzętu komputerowego jest kluczowe, by obniżyć koszty eksploatacji oraz napraw. W pracy przedstawiono również wyniki badań środowiskowych, których celem była ocena zasadność i efektywności stosowania undervoltingu.

12

Ensuring Equal Bandwidth for Remote Connections to the Local Company Server

Muc Adam, Muchowski Tomasz, Kluczyk Marcin, Szeleziński Adam

Multidisciplinary Aspects of Production Engineering

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2020

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Vol. 3, Iss. 1

285--295

EN

Creating the required IT infrastructure to enable the ability for comfortable remote working is not an easy task. Improper configuration can create the possibility of taking over the whole bandwidth of the link by one device. Increasing bandwidth introduces extra costs and does not completely eliminate the problem – it will be more difficult to take over the whole bandwidth, but it is still possible. The solution to the problem may be the use of clouds and VPS, but it is associated with high costs and the need to entrust company data to providers of these services. Due to security and too high costs, this may not be an optimal solution. An alternative solution may be to use QoS along with PCQ. This mechanism allows to ensure equal division of the bandwidth between the devices under its control. With an appropriate configuration, QoS can eliminate the problem of taking over the whole bandwidth and ensure equal access to resources.

13

The Single Degree of Freedom Simulation Model of Underwater Explosion Impact

Grządziela Andrzej, Załęska-Fornal Agata, Kluczyk Marcin

Archives of Acoustics

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2020

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Vol. 45, No. 2

341--348

EN

The hulls of naval ships are exposed to forces and moments coming from internal and external sources. Usually, these are interactions that can be described mathematically by harmonic and polyharmonic functions. The shock of UNDEX type (underwater explosion) works completely differently and its time waveform is difficult to describe with mathematical functions as pressure vs. time. The paper presents a simplification of physical and mathematical models of 1-D kickoff pressure whose aim is performance the simulation of the external force of the detonation wave. The proposed models were verified and tuned on naval, sea trials. The main goals of the proposed models are to perform simulation calculations of the detonation pressure for different explosion charge weights from different distances of the UNDEX epicentre for the design process of machine foundation. The effects of pressure are transformed as impulses exposed on shock absorber mounted at light shock machine.

14

Marine diesel engine common rail injectors monitoring with vibration parameters

Kluczyk Marcin, Grządziela Andrzej

Diagnostyka

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2019

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Vol. 20, No. 3

37--44

EN

The paper presents a results of vibration tests of common rail injectors operating in diesel engines. The most common methods of diagnosing common rail injectors (CR) as well as the most common damage of injectors of this type have been described. The results and analyzes of tests obtained during measurements on two different test stands were presented. Obtained results allowed for the preliminary determination of diagnostically sensitive parameters, which may allow the development of the injector diagnostics method without the need to stopping the engine.

PL

W artykule przedstawiono wyniki badań drganiowych wtryskiwaczy Common Rail pracujących w silnikach o zapłonie samoczynnym zasilanych. Opisano najpowszechniej stosowane metody diagnozowania wtryskiwaczy Common Rail (CR), jak również najczęstsze uszkodzenia wtryskiwaczy tego typu. Zaprezentowano wyniki i analizy badań uzyskane podczas pomiarów na dwóch różnych stanowiskach testowych. Uzyskane wyniki pozwoliły na wstępne określenie parametrów wrażliwych diagnostycznie, co może pozwolić na opracowanie metody diagnostyki wtryskiwaczy bez potrzeby zatrzymywania silnika.