Nauki Techniczne

Bulletin of the Polish Academy of Sciences: Technical Sciences

Zawartość

Bulletin of the Polish Academy of Sciences: Technical Sciences | 2022 | 70 | No. 5

Abstrakt

The paper presents a concept of a new turbine engine with the use of rotating isochoric combustion chambers. In contrast to previously analyzed authors’ engine concepts, here rotating combustion chambers were used as a valve timing system. As a result, several practical challenges could be overcome. An effective ceramic sealing system could be applied to the rotating combustion chambers. It can assure full tightness regardless of thermal conditions and related deformations. The segment sealing elements working with ceramic counter-surface can work as self-alignment because of the centrifugal force acting on them. The isochoric combustion process, gas expansion, and moment generation were analyzed using the CFD tool (computational fluid dynamics). The investigated engine concept is characterized by big energy efficiency and simple construction. Finally, further improvements in engine performance are discussed.
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Autorzy i Afiliacje

Piotr Tarnawski
1
ORCID: ORCID
Wiesław Ostapski
1

  1. Institute of Machine Design Fundamentals, Warsaw University of Technology, Narbutta 84, 02-524 Warsaw, Poland

Abstrakt

The current research focuses on the implementation of the fuzzy logic approach for the prediction of base pressure as a function of the input parameters. The relationship of base pressure (β ) with input parameters, namely, Mach number (M), nozzle pressure ratio (η), area ratio (α), length to diameter ratio (ξ ), and jet control (ϑ ) is analyzed. The precise fuzzy modeling approach based on Takagi and Sugeno’s fuzzy system has been used along with linear and non-linear type membership functions (MFs), to evaluate the effectiveness of the developed model. Additionally, the generated models were tested with 20 test cases that were different from the training data. The proposed fuzzy logic method removes the requirement for several trials to determine the most critical input parameters. This will expedite and minimize the expense of experiments. The findings indicate that the developed model can generate accurate predictions
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Autorzy i Afiliacje

Jaimon D. Quadros
1
ORCID: ORCID
Suhas P.
2
Sher A. Khan
3
ORCID: ORCID
Abdul Aabid
4
Muneer Baig
4
Yakub I. Mogul
5

  1. Fluids Group, School of Mechanical Engineering, Istanbul Technical University, Gümüs¸suyu, 34437 Istanbul
  2. Department of Mechanical Engineering, Sahyadri College of Engineering and Management, Mangaluru 575007, Karnataka, India
  3. Department of Mechanical Engineering, Kulliyyah of Engineering, International Islamic University Malaysia, 53100, Selangor, Malaysia
  4. Department of Engineering Management, College of Engineering, Prince Sultan University, 66833, Riyadh 11586, Saudi Arabia
  5. National Centre for Motorsport Engineering, University of Bolton, Bolton, BL3 5AB, UK

Abstrakt

The modeling of P-waves has essential applications in seismology. This is because the detection of the P-waves is the first warning sign of the incoming earthquake. Thus, P-wave detection is an important part of an earthquake monitoring system. In this paper, we introduce a linear computational cost simulator for three-dimensional simulations of P-waves. We also generalize our formulations and derivation for elastic wave propagation problems. We use the alternating direction method with isogeometric finite elements to simulate seismic P-wave and elastic propagation problems. We introduce intermediate time steps and separate our differential operator into a summation of the blocks, acting along the particular coordinate axis in the sub-steps. We show that the resulting problem matrix can be represented as a multiplication of three multi-diagonal matrices, each one with B-spline basis functions along the particular axis of the spatial system of coordinates. The resulting system of linear equations can be factorized in linear O (N) computational cost in every time step of the semi-implicit method. We use our method to simulate P-wave and elastic wave propagation problems. We derive the condition for the stability for seismic waves; namely, we show that the method is stable when τ < C min{ hx,hy,hz}, where C is a constant that depends on the PDE problem and also on the degree of splines used for the spatial approximation. We conclude our presentation with numerical results for seismic P-wave and elastic wave propagation problems.
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Autorzy i Afiliacje

Marcin Łoś
1
ORCID: ORCID
Pouria Behnoudfar
2
ORCID: ORCID
Mateusz Dobija
3
Maciej Paszynski
1
ORCID: ORCID

  1. AGH University of Science and Technology, Faculty of Computer Science, Electronics and Telecommunications, al. Mickiewicza 30, 30-059 Krakow, Poland
  2. Mineral Resources, Commonwealth Scientific and Industrial Research Organisation (CSIRO), Kensington, Perth, Western Australia
  3. Jagiellonian University, Faculty of Astronomy, Physics and Applied Computer Science, Kraków, Poland

Autorzy i Afiliacje

Paweł Baranowski
1
ORCID: ORCID
Michał Kucewicz
1
ORCID: ORCID
Mateusz Pytlik
2
ORCID: ORCID
Jerzy Małachowski
1
ORCID: ORCID

  1. Military University of Technology, Faculty of Mechanical Engineering, Institute of Mechanics & Computational Engineering, Gen. S. Kaliskiego 2, 00-908 Warsaw, Poland
  2. Central Mining Institute, Conformity Assessment Body, 40-166 Katowice, Poland

Abstrakt

The safety and reliability of the manned airship depend to a considerable extent on its thermal performance. In this paper, heat balance equations are developed and solved in the C++ programming language. The temperature variation of the enclosure, gasbag, and nacelles of the manned airship is investigated. In addition, the effects of season, latitude, and orientation on the thermal performance of the manned airship and the airship nacelle are investigated. The results show that: (1) The average temperature difference of the nacelle surface at the same time is 25 K, while the maximum temperature difference in the nacelle is 29 K during the day, (2) the temperature distribution in the nacelle is similar in spring and autumn, with maximum temperature between 306 K and 309 K. The maximum temperature in the nacelle is between 300 K and 303 K in winter while the maximum temperature in the nacelles is between 309 K and 315 K in summer, (3) as the flight position of the manned airship changes from 20°N to 60°N, the average nacelle temperature varies slightly by about 1 K. However, as the latitude increases, the high- temperature region shifts from the bottom of the nacelle to the side of the nacelle, and (4) the temperature distribution of the upper envelope of the airship varies considerably with orientation. However, the average temperature of the nacelle is less impacted by orientation. These results are useful for understanding the thermal performance of manned airships.
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Autorzy i Afiliacje

Hong Shi
1
Meinan Liu
1
Jiamin Chen
1
Yitao Zou
2

  1. College of Energy and Power Engineering, Jiangsu University of Science and Technology, China
  2. Key Laboratory of Aircraft Environment Control and Life Support, Nanjing University of Aeronautics and Astronautics, China

Abstrakt

A specified weight-cutting system for irregular solid materials such as rubber is important for industrial engineering. Currently, the workers’ experience is used, which has low accuracy and efficiency. A specified weight cutting system for irregular solid material based on 3D scanning is proposed in this paper, which aims to overcome the inaccuracy and inefficiency of the manual cutting process. Firstly, the surface of the irregular solid material is scanned by a tracking 3D laser scanner, and a triangular mesh file is generated. Secondly, the defects of the 3D model are repaired by reverse engineering, and then the 3D model file of the irregular objects is generated. Finally, the cutting position of the specified weight solid material is calculated by the calculation algorithm in UG software. In short, this research creates a new method for processing data collected by the 3D scanner, by working jointly with multiple devices and software, facilitating the cutting of irregular solid materials with specified weights. Additionally, the system has the advantage of accuracy and efficiency over the experience of workers.
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Autorzy i Afiliacje

Jiadong He
1
ORCID: ORCID
Yafeng Huang
2
Xiao Zang
1
Yajun Zhang
1

  1. College of Mechanical and Electrical Engineering, Beijing University of Chemical Technology, Beijing, 100029, China
  2. Xi’an Modern Chemistry Research Institute, Xi’an, 710065, China

Abstrakt

GaSe<CS(NH 2) 2<C 14H 10>> clathrate with a hierarchical subhost<host<guest>> type architecture was formed under illumination and its electrically conductive properties were studied. The method of impedance spectroscopy studied the frequency behavior of the real and imaginary parts of the complex total impedance in the range of 10 -3-10 6 Hz. The measurements were performed under normal conditions, in a permanent magnetic field (220 kA/m), or under light illumination (for a standard solar spectrum AM 1.5 G total available power is 982 W/m 2). The structure of the impurity energy spectrum at the Fermi level was investigated by the method of thermostimulated discharge in the temperature range from 240 to 340 K. Using Jebol-Pollack theoretical approaches based on impedance spectra, the parameters of the impurity energy spectrum were calculated, such as the density of states at the Fermi level, the jump radius , the scatter of trap levels near the Fermi level and the real density of deep traps. As evidenced by studies, illumination during clathrate synthesis, forms an internal electret polarization, which leads to abnormal behavior of the photoresistive effect and to the appearance of the memristive effect. The imposition of a permanent magnetic field during the measurement of complex resistance leads to the appearance of quantum capacitance.
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Autorzy i Afiliacje

Fedir Ivashchyshyn
1 2
ORCID: ORCID
Vitaliy Maksymych
2
ORCID: ORCID
Dariusz Calus
1
ORCID: ORCID
Dariya Matulka
2
ORCID: ORCID
Piotr Chabecki
1
ORCID: ORCID
Andrii Kunynets
2
ORCID: ORCID

  1. Czestochowa University of Technology, Al. Armii Krajowej 17, 42-200 Częstochowa, Poland
  2. Lviv Polytechnic National University, Bandera Str. 12, Lviv, 79013, Ukraine

Abstrakt

This paper deals with rotational moulding. The relationship between mould speed and wall thickness in the upper, middle and lower areas of rotational moulded parts is investigated. Young’s modulus of moulded parts is determined via static tensile testing. A static compression test is performed to determine the maximum compressive force causing strain. The test is conducted on the wall of moulded parts, parallel to the main axis of rotation. Also, energy consumption in rotational moulding is investigated for different rotational speeds of the mould. Moulded parts are made of DOWLEX®2629UE linear low-density polyethylene (LLDPE). Experimental results are statistically analysed using STATISTICA 13. Non-parametric statistical tests are used for results analysis. The ANOVA method is employed to determine if there are any significant differences between obtained results. The statistical tests show that the range is much narrower for a speed ratio of 4:1. The narrowest range value is obtained for 12 3 rpm. The highest Young’s modulus values are obtained for the parts moulded at 12 3 rpm (1263.33 MPa) and 16 4 rpm (1263.67 MPa). The highest maximum compressive force is obtained for the parts moulded at 12 3 rpm (10 400 N). An analysis of the results demonstrates that the part moulded at 12 3 rpm has the most advantageous properties. For this mould speed, the power consumption amounts to 8.28 kWh. Experimental results and statistical analyses demonstrate that mould speed affects both moulded part quality and energy consumption in the rotational moulding process.
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Autorzy i Afiliacje

Karolina Głogowska
1
ORCID: ORCID
Filip Longwic
1
Krzysztof Ludziak
2

  1. Department of Technology and Polymer Processing, Faculty of Mechanical Engineering, Lublin University of Technology, Poland
  2. Department of Sustainable Transport and Powertrains, Faculty of Mechanical Engineering, Lublin University of Technology, Poland

Abstrakt

A review of the Miller, Laue and direction indices characterization was made. Excluding or allowing non-coprime indices, depending on whether the lattice is primitive or centred, were compared. The solution of the “spacing counting problem for centred lattices was proposed. It was shown that for centred lattices: (1) Laue indices nh nk nl can represent not only n-th order diffraction on (hkl) planes, but also the first order diffraction from a family of planes (nh nk nl); (2) “integral reflection conditions” are necessary, but not sufficient for the existence of given Miller indices. “Integral reflection conditions” for Laue indices hkl and other “conditions for Miller indices” (hkl) were distinguished. It was shown that in the case of centred lattices, the inference based on the value of n obtained from the equation of lattice planes, may not be correct. The homogeneity of the centred reciprocal lattices has been clarified. “Simple cubic cell with a base” as a choice of unit cell proposed by “general rule” was contrasted with: “unit cell, if not centred, must be the smallest one”. “Integral reflection conditions” for Laue indices and other, new “conditions for Miller indices”, resulting from transformation of centred lattices to unconventional primitive ones have been proposed. Examples of the not correct use of indices in the morphology and diffraction pattern descriptions were shown.
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Autorzy i Afiliacje

Edward Michalski
1
ORCID: ORCID

  1. Institute of Optoelectronics, Military University of Technology, Gen. Sylwestra Kaliskiego 2, 00-908 Warsaw, Poland

Autorzy i Afiliacje

Sebastian Słomiński
1
ORCID: ORCID

  1. Warsaw University of Technology, Institute of Electrical Power Engineering, Lighting Technology Division, Koszykowa 75, 00-662 Warsaw, Poland

Abstrakt

The paper is a structured, in-depth analysis of dual active bridge modeling. In the research new, profound dual active bridge converter (DAB) circuit model is presented. Contrary to already described idealized models, all critical elements including numerous parasitic components were described. The novelty is the consideration of a threshold voltage of diodes and transistors in the converter equations. Furthermore, a lossy model of leakage inductance in an AC circuit is also included. Based on the circuit equations, a small-signal dual active bridge converter model is described. That led to developing control of the input and output transfer function of the dual active bridge converter model. The comparison of the idealized model, circuit simulation (PLECS), and an experimental model was conducted methodically and confirmed the high compatibility of the introduced mathematical model with the experimental one. Proposed transfer functions can be used when designing control of systems containing multiple converters accelerating the design process, and accurately reproducing the existing systems, which was also reported in the paper.
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Autorzy i Afiliacje

Roman Barlik
1
Piotr Grzejszczak
1
Mikołaj Koszel
1

  1. Warsaw University of Technology, Warsaw, Poland

Abstrakt

Fog networks facilitate ultra-low latency through the use of data availability near the network edge in fog servers. Existing work in fog networks considers the objective of energy efficiency and low latency for internet-of-things (IoT) for resource allocation. These works provide solutions to energy efficiency and low latency resource allocation problem without consideration of secure communication. This article investigates the benefits of fog architecture from the perspective of three promising technologies namely device-to-device (D2D) communication, caching, and physical layer security. We propose security provisioning followed by mode selection for D2D-assisted fog networks. The secrecy rate maximization problem is formulated first, which belongs to mixed-integer nonlinear programming (MINLP) problem. It is NP-hard, that is why an exhaustive search for finding the solution is complex. Keeping in view the complexity, a nonlinear technique namely outer approximation algorithm (OAA) is applied. OAA is a traditional algorithm, whose results are compared with the proposed heuristic algorithm, namely the security heuristic algorithm (SHA). Performance of the network is observed for the different numbers of eavesdroppers, IoT nodes, and fog nodes.
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Autorzy i Afiliacje

Rabeea Basir
1
ORCID: ORCID
Naveed Ahmad Chughtai
2
Mudassar Ali
2 3
Saad Qaisar
1 4
Anas Hashmi
4

  1. School of Electrical Engineering and Computer Science (SEECS), National University of Sciences and Technology, Islamabad, Pakistan
  2. Military College of Signals, National University of Sciences and Technology, Rawalpindi, Pakistan
  3. Telecommunication Engineering Department, University of Engineering and Technology, Taxila
  4. Department of Electrical and Electronic Engineering, University of Jeddah, Jeddah, Saudi Arabia

Abstrakt

In this paper the controllability properties of the convex linear combination of fractional, linear, discrete-time systems are characterized and investigated. The notions of linear convex combination and controllability in the context of fractional-order systems are recalled. Then, the controllability property of such a linear combination of discrete-time, linear fractional systems is proven. Further, the reduction of an infinite problem of transition matrix derivation is reduced to a finite one, which greatly simplifies the numerical burden of the controllability issue. Examples of controllable and uncontrollable, single-input, linear systems are presented. The possibility of extension of the considerations to multi-input systems is shown.
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Autorzy i Afiliacje

Tadeusz Kaczorek
1
ORCID: ORCID
Jerzy Klamka
2
ORCID: ORCID
Andrzej Dzieliński
3
ORCID: ORCID

  1. Bialystok University of Technology, Faculty of Electrical Engineering, ul. Wiejska 45D, Bialystok, Poland
  2. Institute of Theoretical and Applied Informatics, Polish Academy of Sciences, ul. Bałtycka 5, Gliwice, Poland
  3. Warsaw University of Technology, Faculty of Electrical Engineering, ul. Koszykowa 75, Warsaw, Poland

Abstrakt

Fault location, isolation and self-restoration (FLISR) automation is an essential component of smart grids concept. It consists of a high level of comprehensive automation and monitoring of the distribution grid improving the quality of energy supplied to customers. This paper presents an algorithm for decentralized FLISR architecture with peer-to-peer communication using IEC 61860 GOOSE messages. An analysis of short circuit detection was presented due to the method of the grid earthing system. The proposed automation model was built based on communication logic between configured intelligent electronic devices (IED) from ABB and Siemens. The laboratory tests were conducted in a half-loop grid model with a bilateral power supply (typical urban grid). The laboratory research concerned three locations of short circuits: between substation and section point, between two section points and between section point and normally open point (NOP). The logic implementation was developed using State Sequencer software offered by Test Universe.
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Autorzy i Afiliacje

Paweł Bielenica
1
Joanna Widzińska
2
Artur Łukaszewski
2
ORCID: ORCID
Łukasz Nogal
2
ORCID: ORCID
Piotr Łukaszewski
2

  1. ENCO Sp. z o.o., Poste˛ pu 13, 02-676 Warsaw, Poland
  2. Electrical Power Engineering Institute, Faculty of Electrical Engineering, Warsaw University of Technology, Koszykowa 75, 00-662 Warsaw, Poland

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